A state of the art computational fluid dynamic methodology is proposed for first-principles-based simulation of detonation in FAE clouds. The approach is based on extensions of well proved and established technology currently in routine use for multiphase, chemically reacting and turbulent solid… More

Existing technology for the 3D CFD analysis of rocket plume/aerodynamic interactions will be specialized to the ejection seat problem. Present technology includes a 3D Navier-Stokes code, CRAFT, with detailed plume thermochemistry and multiphase flow and with turbulence models specialized to the… More

Extensions of a 3D upwind/implicit multiphase flow computer code (CRAFT) to simulate complex flow patterns associated with chemical/biological (C/B) agent release resulting from missile impact and from destruction of storage containers due to blast impact are proposed. The problems to be dealt with… More

This Phase I proposal involves initiating the path to properly simulating non-equilibrium multiphase flowfields utilizing advanced numerical techniques. Computational fluid dynamics (CFD) methodology for predicting steady and transient, chemically reacting, two - and three-dimensional, multiphase… More

The systematic upgrade of a two-phase (gas/particle) missile propulsive Navier-Stokes code, CRAFT, to simulate the three-phase combustive processes occurring in rocket combustion chambers and nozzles is proposed. Preliminary emphasis is on upgrades that will improve the ability to analyze… More

A state-of-the art CFD methodology that has well established aero-acoustic capabilities will be implemented for -investigating turbulence/acoustic interactions that characterize cavity flowfields. Exploratory numerical investigations will be conducted using the three-dimensional, finite volume … More

The systematic upgrade of a two-phase (gas/particle) missile propulsive Navier-Stokes code, CRAFT, to simulate the three-phase combustive processes occurring in rocket combustion chambers and nozzles is proposed. Preliminary emphasis is on upgrades that will improve the ability to analyze… More

A state-of-the art CFD methodology that has well established aero-acoustic capabilities will be implemented for -investigating turbulence/acoustic interactions that characterize cavity flowfields. Exploratory numerical investigations will be conducted using the three-dimensional, finite volume … More

An advanced computational framework for scramjet combustor simulation will be developed via turbulence extensions to a finite-volume implicit/upwind Navier-Stokes code that presently contains generalized multiphase combustive capabilities and is operational on parallel architecture machines using… More

A three-phase Navier-Stlkes code (CRAFT) that has been applied to varied multi-phase combustion problems, including high explosive (HE) detonation, blast wave interactions with bulk liquid, particulate dispersion and entrainment by turbulence, etc., will be specialized to address the end-to-end CB… More

Not Available A number of thin film deposition techniques such as rf magnetron sputtering, dual ion beam assisted deposition (DIBAD), ion assisted dynamic mixing, high pressure synthesis of sp2 bonded carbon nitrides, thermal decomposition of molecular precursors, an even high pressureshock wave… More

The proposed program provides for the development of advanced RANS/LES CFD methodology to permit the evaluation and design of advanced fuel injection concepts to enhance mixing and combustion in scramjets. These concepts will result in longer range andshorter time to target for next generation… More

The innovation proposed is the construction of a unified nonlinear turbulence model for use in jet noise studies that will operate in an invariant manner (fixed coefficients/correction terms), and will provide reliable mean flow and anisotropic stresses predictions for a broad range of jet… More

Large dynamic pressure loads occur on missile airframes produced by aerodynamic interactions associated with lateral/divert jet firings and from varied separation events (stage, shroud, submunitions dispense). The accurate prediction of such loads is acritical element of missile design since… More

Interceptor missiles achieve high maneuverability in final phases of their mission via the use of divert/attitude control jets. Jet firings are of relatively short duration (10-40ms) and the aerodynamic interaction process is highly transient,characterized by large regions of jet-induced… More

Numerical simulation of store separation from weapons bays or wing pylons is made difficult by the need to move the computational mesh and provide adequate resolution of flow structures that are changing with time. Recent advances in unstructured gridmethods have demonstrated that an adaptive grid,… More

The application of airborne and ground-based high power lasers as Directed Energy (DE) weapons is under consideration for the Joint Strike Fighter (JSF). Depending upon the integration selected for the laser, varied forms of turbulence is encountered alongthe beam propagation path, e.g. turbulent… More

The task of computationally simulating the dispersion and/or neutralization of toxic chemical/biological (CB) agents, released from weapons of mass destruction (WMD), puts a very high demand on the capability of current generation computational dynamics(CFD) codes. Current advanced computational… More

An internal aircraft weapons bay, when exposed to freestream flow, experiences an intense aeroacoustic environment and varied suppression concepts have been tested for attenuating flow-induced oscillations. Recent tests with open-loop, high-frequencyexcitation have shown great promise in providing… More

An internal aircraft weapons bay, when exposed to freestream flow, experiences an intense aeroacoustic environment and varied suppression concepts have been tested for attenuating flow-induced oscillations. Recent tests with open-loop, high-frequencyexcitation have shown great promise in providing… More

"Interceptor missiles achieve high maneuverability in final phases of their mission via the use of divert/attitude control jets. Jet firings are of short duration (10-40ms) and the entire process from firing to shut-off is of concern and requires veryaccurate modeling. Aerodynamic interactions are… More

"Dynamic pressure loads on missile airframes can produce severe vibrations which can be transmitted to sensitive internal components. Our Phase I effort initiated the development of a high fidelity computational package to predict such loads. A hybridRANS-LES framework was made operational… More

"The application of airborne Directed Energy (DE) weapons is under consideration for the Joint Strike Fighter (JSF) and Unmanned Combat Air Vehicles (UCAV). Intense turbulence is encountered along the beam propagation path in the aircraft nearfield, e.g.boundary layer, free shear layer, or wake.… More

"Numerical simulation of store separation from weapons bays or wing pylons is made difficult by the need to move the computational mesh and provide adequate resolution of flow structures that are changing with time. The Phase I achievements demonstratethat an adaptive grid, which is coarsened… More

"Solution of the Navier-Stokes equations for modeling 3D interceptor missile flowfields and divert jet interactions requires the availability of high performance, massively parallel, computing facilities since the grid resolution requirements and largeequation sets can necessitate runtimes exceeding… More

"The time-varying plume infra-red (IR) signature modulation provides a marker that allows a plume signal to be discriminated, in frequency space, from a cluttered background. From the perspective of Ballistic Missile Defense (BMD), it provides a novelopportunity for boost phase detection of targets.… More

"High-fidelity TBM rocket plume simulations performed using the CRAFT CFD code (under MDA, MSIC and AFRL support) for boost phase intercept studies, indicate the need to improve modeling capabilities in the 40-80 km altitude regime. At 40-60 km, modelingcomplexities entail predicting plume-induced… More

"In a recent Army Scramjet Technology Evaluation Program, full scale scramjet models (Hyper-X and Air Force type configurations) were tested at fully duplicated flight conditions in the CUBRC LENS shock tunnel facility. This data in conjunction withhigh-fidelity CFD studies, has identified the… More

"The extended transient exhaust plume from hypervelocity tactical missiles contains particulates which degrade EM waves used for guidance and/or tracking. Our proposed Phase I effort initiates the development of an efficient parallel architecture frameworkto analyze the complete transient plume,… More

"Laser beam interactions with free shear turbulent structures in the context of a recessed cavity window will be investigated. The proposed program will investigate the aero-optic degradation of a laser beam, housed within the cavity, and its remediationusing high frequency flow control. Beam wander… More

An innovative model for simulating cavitation in liquid rocket turbopumps using cryogenic working fluids is proposed. The formulation is based on a compressible gas-liquid framework that accurately models the acoustics in a multi-phase mixture. This methodology was successfully applied, in our Phase… More

An innovative model for simulating cavitation in liquid rocket turbopumps using cryogenic working fluids is proposed. The formulation is based on a compressible gas-liquid framework that accurately models the acoustics in a multi-phase mixture. This methodology was successfully applied, in our Phase… More

"Integration of aviation units with air capable Navy ships has always been a challenge. V/STOL aircraft, e.g. AV-8B, JSF, etc. encounter unique challenges in performing takeoff and landing during the course of shipboard operations due to the interaction ofthe propulsion-generated jet downwash with… More

This Small Business Innovation Research Phase I project will study an innovative formulation for simulating unsteady cavitation phenomena in pumps. The formulation is based on a compressible gas-liquid framework that accurately models the acoustics in multi-phase mixtures, and may be extended to… More

Massively parallel clusters of commercial off-the-shelf (COTS) computers provide the best opportunity for cost-effective missile flowfield solutions, but extensions to CFD and hardware are needed before their routine application to real problems can beeffective. This joint CRAFT Tech/COLSA effort,… More

The time-varying plume infra-red (IR) signature modulation provides a marker that allows a plume signal to be discriminated, in frequency space, from a cluttered background. From the perspective of Ballistic Missile Defense (BMD), it provides a novelopportunity for Early Launch Detection & Tracking… More

The extended transient exhaust plume from hypervelocity tactical missiles contains particles, which degrade EM waves used for guidance and/or tracking. Our proposed Phase II effort continues the development of an efficient parallel architecture frameworkto analyze the complete transient plume, from… More

The innovation proposed is the construction of a unified nonlinear turbulence model for use in jet noise studies that will operate in an invariant manner (fixed coefficients/correction terms), and will provide reliable mean flow and anisotropic stresses predictions for a broad range of jet… More

Characteristics of missile plume signature emissions have a great potential to enhance defensive capabilities in a number of important areas related to early (boost-phase) detection and identification of the missile system/rocket motor. Missile defensetechnologies where plume modeling plays a… More

The innovation for this Phase I program is the performance of a scope-out study that quantifies missile body heating effects due to plume interactions in the continuum altitude range of 30-80 km where plume induced separation is significant. The size andcharacteristics of the separation zone at… More

The innovation proposed for Phase I is the examination of two concepts for reducing turbulence-generated pressure-oscillations in a 90¿ bend and in a tee-duct. The first concept is based on introducing fine-grain, high-frequency turbulence just upstreamof the separated zone via a thin-rod shedding… More

Computational analyses aiding experimental testing of rocket propulsion systems have very rigorous requirements relating to turnaround time and fidelity of analyses. The performance of rocket propulsion systems is intricately tied to the functioning of valve and feed systems, since feed systems… More

Hypervelocity kinetic energy missiles such as the CKEM are being designed utilizing multistage Booster-Sustainer configurations. Concepts entail different methods to separate booster and sustainer stages including passive drag, pyrotechnically-assisted,and, sustainer-motor-ignition-assisted… More

The innovation is the inclusion of generalized 6DOF analysis methodology into advanced structured grid (CRAFT CFD) and unstructured grid (CRUNCH CFD), three-dimensional, time-accurate Navier-Stokes codes. This will permit the high fidelity simulation of abroad range of missile separation problems… More

The innovation proposed is the construction of a unified nonlinear turbulence model for use in jet noise studies that will operate in an invariant manner (fixed coefficients/correction terms), and will provide reliable mean flow and anisotropic stresses predictions for a broad range of jet… More

The time-varying plume infra-red (IR) signature modulation provides a marker that allows a plume signal to be discriminated, in frequency space, from a cluttered background. From the perspective of Ballistic Missile Defense (BMD), it provides a novelopportunity for boost phase detection of targets.… More

Our proposal addresses the high fidelity simulation of dynamic, post-burnout propulsive related events whose radiative characteristics are observable by space-based optical sensors. Events include persistent trails, fuel venting, tank rupture, etc. Wewill utilize a very advanced compressible… More

Understanding the transient events in plume signature emissions has a great potential to enhance defensive capabilities in a number of important areas related to early warning launch detection, post launch warning detection, missile typing algorithms,discrimination and background clutter… More

Plume/divert jet interactions on both missile performance and aerothermal effects (seeker window obscuration and heating) are a major concern at higher altitudes where the separation zone produced by these interactions can engulf a large portion of theoverall missile flowfield. Predictive… More

The field of CFD has witnessed dramatic maturation of unstructured, hybrid multi-element technology, along with implementation of such simulation methodology on large-scale multi-processor parallel, computational architecture. Absence of equivalent forradiative transfer simulations limits design or… More

The field of CFD has witnessed dramatic maturation of unstructured, hybrid multi-element technology, along with implementation of such simulation methodology on large-scale multi-processor parallel, computational architecture. Absence of equivalenttechnology for radiative transfer simulations limits… More

The innovation entails the extension of newly developed hypersonic transitional models and hybrid continuum/DSMC methodology to analyze plume and divert jet interactions at altitudes above 45km where present predictive capabilities are deficient due tocomplexities in the physics. In the altitude… More

The proposed effort entails the development of a CFD simulation framework for the modeling of coupled airwake-V/STOL flow fields. A novel strategy that combines a compressible and an incompressible flow solver is proposed, in which, the different regionsof the flow are computed using algorithms that… More

The proposed effort entails the development of a CFD simulation framework for the modeling of coupled airwake-V/STOL flow fields. A novel strategy that combines a compressible and an incompressible flow solver is proposed, in which, the different regionsof the flow are computed using algorithms that… More

In this Phase II program, we will obtain new data sets in the CUBRC LENS shock tunnel facility that duplicate true flight conditions and can be used to improve the predictive capabilities of missile/plume CFD models in the 35-70 km altitude regime. Tests will systematically vary altitudes and Mach… More

A program to develop flow control techniques to reduce aero-optic distortion due to near field turbulence is proposed. The program combines the use of advanced computational techniques such as Large Eddy Simulations, new experimental methods such as Particle Image Velocimetry (PIV) and Laser Speckle… More

Characteristics of missile plume signature emissions have a great potential to enhance defensive capabilities in a number of important areas related to early (boost-phase) detection and identification of the missile system/rocket motor. Missile defense technologies where plume modeling plays a… More

The development of simulation technology is proposed for carrying out high-fidelity transient analyses of systems that support experimental rocket testing such as control valves, feed system elements, pressure regulators and other flow control elements. The simulation technology comprises of a… More

The time-varying plume infra-red (IR) signature modulation provides a marker that allows a plume signal to be discriminated, in frequency space, from a cluttered background. From the perspective of Ballistic Missile Defense (BMD), it provides a novel opportunity for Early Launch Detection & Tracking… More

This effort entails the modeling of a variety of propulsive related missile phenomena of interest to MDA with an emphasis on lower altitude (h< 70km) problems, as well as on continuum/non-continuum bridging to provide the correct initial conditions for DSMC solutions. Phenomena to be modeled… More

The innovation for this Phase I program is the development of advanced high-fidelity techniques for the analysis of moving transient plumes at high altitudes, accounting for their distortion and trajectory changes due to interactions with the surrounding atmosphere, as well as procedures for… More

There currently are no analytical or CFD tools that can reliably predict unsteady cavitation dynamics in liquid rocket cryogenic systems. Analysis of cavitating cryogenic systems presents a challenge, and is poorly understood, because the phase change process couples with the temperature… More

Our proposal addresses the inclusion of a secondary smoke model into a modern CFD code that is widely used for plume simulations. This will permit high fidelity simulations of dynamic, missile exhaust plume flowfields that, under certain conditions, produce a condensation cloud that can obscure the… More

Our proposal addresses the inclusion of a secondary smoke model into a modern CFD code that is widely used for plume simulations. This will permit high fidelity simulations of dynamic, missile exhaust plume flowfields that, under certain conditions, produce a condensation cloud that can obscure the… More

A program to demonstrate a Computational Fluid Dynamics (CFD) technology for the prediction of Helmholtz resonance in openings on submarine hull structures is proposed. The program seeks to build upon established technology developed under funding from the US Navy for the modeling and study of… More

The task of computationally simulating the dispersion and/or neutralization of toxic chemical/biological (CB) agents, released from weapons of mass destruction (WMD), puts a very high demand on the capability of current generation computational dynamics (CFD) codes. Current advanced computational… More

A new hybrid model will be developed under this Phase II effort predicting the propagation of transient bursts at high-altitudes that can be used to design and evaluate flux-based discrimination concepts. The hybrid model has 3D continuum (CRAFT CFDr Code), DSMC (DAC97 Code), and free molecular… More

There currently are no analytical or CFD tools that can reliably predict unsteady cavitation dynamics in liquid rocket turbopumps. Cavitation effects, particularly at low-flow, off-design conditions, generate large amplitude pressure fluctuations that result in performance loss, and may interact… More

The proposed Phase II effort aims to develop, validate and demonstrate a Computational Fluid Dynamic (CFD) tool capable of predicting the occurrence of Helmholtz resonance in cavities in underwater vehicles. Preliminary validation of the CFD tool and identification of numerical fidelity parameters… More

Our Phase I program entails examining the addition of micron and nano-sized aluminum particles to hydrogen fuel for use in hypersonic (M>8) scramjet propulsive flowpath concepts being evaluated for long range missile applications. CFD methodology will be used in these studies that has been validated… More

Jet noise mitigation techniques are currently under evaluation by CRAFT Tech and NCPA for application to the F/A-18 E/F aircraft. Varied passive technologies, e.g. microjet blowing, corrugations, etc. analyzed at 1/10th scale culminated in full-scale propulsion stand tests of a F404-400 engine… More

The accurate prediction of missile plume signatures within the afterburning shutdown regime plays a crucial role in the development of a number of missile defense technologies for Boost Phase Intercept (BPI). These include algorithms for plume-to-hardbody handover, aimpoint selection, system typing,… More

High-fidelity missile plume flowfield simulations of MDA interest require use of detailed chemical kinetic mechanisms, which significantly improve IR/UV/RCS/visible signature prediction but entail long solution runtimes for completion. These long runtimes result from the required iterative solution… More

The innovation for this Phase I program is the extension of the new Rocket Plume Flowfield Model (RPFM) to analyze Reentry Vehicle (RV) body flows. The Phase I effort provides the foundation for a highly optimized, fast-running Reentry Vehicle Flowfield Model (RVFM) for analysis of thermal… More

Recent work in high speed reacting flows has identified three areas in which model improvements are needed. (1) Multi-element grid adaptation for fuel injection problems - h-refinement (cell splitting) procedures being utilized in our grid adaptation tool, CRISPr, produce large meshes after several… More

CFD based analyses are playing an increasingly important role in supporting experimental testing of rocket propulsion systems. The focus of this proposal is towards identifying and characterizing flow induced instabilities in the experimental test facility. Computational simulations will be carried… More

The innovation is the systematic "building-block" validation of CFD/turbulence models employing a GUI driven CFD code (RPFM) and existing as well as new data sets to be generated in this proposed program. Unified ke and algebraic stress (EASM) turbulence models, shown to adequately simulate… More

The innovation is demonstrating how the addition of aluminum particles to hydrogen fuel, for a hypersonic scramjet, can enhance overall performance while reducing volumetric fuel storage requirements. In Phase I, preliminary "one-way" Al burn rate models were formulated, relevant at… More

The proposed Phase II program will lead to the development & demonstration of a highly optimized, fast-running 3D Reentry Vehicle Flowfield Model (RVFM3D) for performing trajectory analysis of Reentry Vehicle flowfields. The RVFM3D model will feature innovative methodology that will couple the RV… More

High-fidelity flowfield simulations of US Army interest for tactical and hypersonic missile aeropropulsive applications require replacement of simplified modeling approximations with more accurate but complex formulations. These improvements have incurred significant computational cost through use… More

High-fidelity flowfield simulations of US Army interest for tactical and hypersonic missile aeropropulsive applications require replacement of simplified modeling approximations with more accurate but complex formulations. These improvements have incurred significant computational cost through use… More

CFD codes used to simulate upper stage expander cycle engines are not adequately mature to support design efforts. Rapid and accurate simulations require more versatile grid frameworks to handle complex geometries of multi-element injector configurations. Turbulence models require upgrades to… More

A hybrid continuum/noncontinuum computational model will be developed for analyzing the aerodynamics and heating on aeroassist vehicles. Unique features of this model include (1) the ability to model rarefied flows with localized continuum features at high altitudes, (2) the ability to model both… More

Reliable diagnostic tools to support system health monitoring are critical both for liquid rocket experimental ground test facilities and flight systems. Here, flow induced instabilities can generate flow anomalies such as large scale pressure fluctuations that may couple with other system… More

The solution of the 3D unsteady Navier-Stokes fluid mechanics equations, coupled to the Maxwell's equations for electrical propagation, is being conducted utilizing an innovative Multi-Physics Simulation (MPS) Architecture. The MPS Architecture provides efficient resolution of a key technical… More

Our proposal addresses the high fidelity modeling of transient rocket exhaust plumes in a static test environment. Static testing provides a practical means of obtaining plume signature and interference data to support model validation. However, existing CFD codes routinely used for plumes in… More

Development of a surface measurements based active feedback flow control strategy for cavity flow fields is proposed. The method relies on the estimation of flow field characteristics using surface pressure measurement. The estimated flow field will be used by a controller to provide suitable… More

The program focuses on turbulence modeling enhancements for predicting high-speed rocket base flows. A key component of the effort is the collection of high-fidelity data for supporting turbulence model validation and calibration. Base flow configurations of interest to NASA Marshal will also be… More

Solution errors are inherent in any Computational Fluid Dynamics (CFD) simulation. Sources of error include spatial and temporal discretization, inadequacy or incapacity of physical models to capture complex fluid flow phenomena, and human errors in the setup and use of the CFD code. Systematic… More

Intense dynamic and thermal loads will occur during stage-separation events that are of major concern from both operational and safety viewpoints. The insensitive-munitions (IM) stimuli and thermal/dynamic response associated with such events has received very little attention, yet this is of major… More

The proposed effort focuses on fuel/air mixing in scramjet environments, as well as on optimization of fuel injector designs and patterns. Turbulence model upgrades will focus on predicting Prandtl and Schmidt number variations using a scalar fluctuation model (SFM) validated for a limited number of… More

Recently developed gas/liquid (G/L) methodology, being used for cavitating flow problems, and extended for all-speed operability using preconditioning, will be used to analyze fuel jet atomization in high-speed military gas turbines. This methodology can capture G/L interfaces, and using… More

The F/A-22 main weapons bay experiences severe acoustic loading when exposed to the freestream. The severity and attenuation of this loading is exacerbated by the flight envelope of the F/A-22 aircraft, as well as the requirement to carry and release "smart" weapons throughout this envelope. This… More

The technical objective of this program is to develop a fast running, subgrid scale turbulence-chemistry interaction model for large-eddy simulation (LES) of aircraft augmentors that can accurately capture extinction and ignition effects. To accurately capture extinction and ignition, this model… More

The next generation liquid rocket systems envision novel designs for turbopumps that can operate at high suction speeds (i.e. low inlet pressures), and can be throttled over a wide range of low, off-design flow conditions. This is an extremely demanding flow regime where performance loss and damage… More

This program will develop the technology needed to design active combustion control (ACC) techniques using energetic secondary fuel injection concepts. We will use the ACC experiments of Yu (UMD) and the energetic fuel research of Yetter (PSU) as stepping-stones. CRAFT Tech will assess and validate… More

Simulation technology plays an important role in rocket engine test facility design and development by assessing risks, identifying failure modes and predicting anomalous behavior of critical systems. Advanced numerical tools assume greater significance in supporting testing and design of high… More

The proposed effort addresses a need for accurate computational models to support aeroassist and entry vehicle system design over a broad range of flight conditions including direct entry and aerocapture trajectories for manned and unmanned earth return and planetary exploration. These models are… More

Novel techniques for jet noise mitigation and plume IR attenuation techniques will be evaluated by CRAFT Tech and NCPA for application to the F/A-18 E/F and the Joint Strike Fighter (JSF) aircrafts. Two concepts, featuring corrugated nozzle seals and lobed ejector seals, will be analyzed at 1/10th… More

In-space valves for the main fuel and oxidizer feed systems are required to provide precise control, wide throttling range and handle rapid on-off control. These design requirements result in significant unsteady, transient effects both on the fluid mass flow rate, as well as the torque required… More

The proposed effort addresses a current need for high fidelity simulation tools to support the design and analysis of combustion devices for the Constellation program and Exploration Mission that includes earth-to-orbit, upper stage, as well as in-space propulsion systems. Injector designs are a… More

Solution errors are inherent in any Computational Fluid Dynamics (CFD) simulation. Sources of error include spatial and temporal discretization, inadequate physical models, and human errors in the setup and use of the CFD code. Systematic identification, reduction, and control of these various… More

A Phase I program is proposed which lays the groundwork for validation of CFD to accurately model heated exhaust plume discharge from non-conventional exit configurations into low-speed crosswinds. A key component of the Phase I effort is development of a detailed experimental plan to acquire… More

Our proposal addresses the enhancement of design capabilities for supersonic inlets using advanced CFD methodology integrated with efficient design-optimization procedures in an automated, GUI driven framework. Three-dimensional CFD solvers, coupled with design optimization techniques, can now… More

A surface pressure measurement based closed loop adaptive flow control strategy for the minimization of dynamic loads caused by high subsonic/supersonic flow over a cavity is proposed. In the Phase I part of this program we have focused on the examining the feasibility of this approach and… More

The proposed research program aims to develop an efficient, high-fidelity simulation tool for ship-board flight testing of unmanned aerial vehicles (UAVs) that provides a computational testbed for UAV design, autonomous control system design, and UAV/Ship integration analysis. The envisioned flight… More

The development of a trajectory envelope prediction tool, capable of identifying stores that may experience significant trajectory deviations due to unsteady loading is proposed. The Phase I part of this program will provide a comprehensive demonstration of the significance of these unsteady loads… More

The JSF weapons bay experiences severe acoustic loading when exposed to the freestream. The severity and attenuation of this loading is exacerbated by the flight envelope of the JSF aircraft, as well as the requirement to carry and release "smart" weapons over an extended envelope. This extremely… More

The innovation is that of using blast-based concepts for the hypersonic/endo dispense of an array of small hardened projectiles (SHAPs) from an interceptor missile. Hit-to-kill successes using this SHAP concept will be significantly enhanced from that of conventional, single warhead concepts, akin… More

Intense dynamic and thermal loads will occur during stage-separation events that are of major concern from both operational and safety viewpoints. The insensitive-munitions (IM) stimuli and thermal/dynamic response associated with such events has received very little attention, yet this is of major… More

This effort entails the validation of a RANS turbulent scalar transport model (SFM) for high speed propulsive flows, using new experimental data sets and accompanying large-eddy simulation (LES) solutions. The SFM has been used to predict local values of the turbulent Prandtl and Schmidt numbers and… More

This proposal entails the development of specialized CFD models which can analyze transpiration cooling processes in complex high-speed environments. This is of significant importance to the Army since "well-designed" transpiration concepts are needed on missile systems that can provide reductions… More

The overall goal of this STTR program is to develop an efficient, high-fidelity, CFD-based design tool for the simulation of ship-board flight testing of autonomous UAV systems. In Phase I, an overall flight simulation framework that employs a modular approach to the flight simulation problem was… More

This program entails designing a Mach 10, scramjet propelled missile system using advanced CFD and design-optimization tools. The CFD codes were validated using full-scale data sets obtained from tests performed in the LENS shock tunnel facility. They contain advanced turbulence and thermochemical… More

A new chemical kinetics model and database will be developed for aerothermodynamic analyses on entry vehicles. Unique features of this model include (1) the ability to model chemical kinetics in highly nonequilibrium flows at high altitudes, (2) the ability to predict nonequilibrium dissociation… More

Propulsion systems may perform a variety of maneuvers during the ascent phase of flight that can impact the performance of an interceptor or other parts of an MDA system designed to perform threat detection, discrimination, and tracking. Our Phase I effort focuses on building on extending existing… More

A unified comprehensive framework that incorporates Maxwell's equations coupled with the 3D unsteady Navier-Stokes equations of fluid mechanics, is being developed utilizing an innovative Multi-Physics Simulation (MPS) Architecture, for conducting multi-disciplinary simulations. The MPS Architecture… More

The innovation proposed is the development of a high-fidelity software tool to be used for the design of hypersonic UAV dispense and subsequent dispense and dispersion of small hardened projectiles (SHAPs) from the UAVs using blast-based concepts. Such dispersed kinetic energy concepts can be… More

A joint analytical/experimental program to develop technologies to improve thermal output from combustors in propulsion systems while ensuring their stable operation is proposed. The program will exploit the use of energetic materials as secondary fuels to be injected suitably into the combustors to… More

The F-22A main weapons bay experiences severe acoustic loading when exposed to the freestream. The severity and attenuation of this loading is exacerbated by the flight envelope of the F-22A aircraft, as well as the requirement to carry and release "smart" weapons throughout this envelope. This… More

Next generation liquid rocket systems envision novel designs for turbopumps that can operate at high suction speeds (i.e. low inlet pressures), and can be throttled over a wide range of low, off-design flow conditions. This is an extremely demanding flow regime where performance loss and damage… More

Upgrades to a RANS Scalar fluctuation model (SFM) used to predict variations in turbulent Prandtl and Schmidt numbers in a scramjet combustor environment are proposed. Such upgrades will permit obtaining more accurate solutions leading to improved combustor designs. Experiments to be performed in… More

Simulation technology plays an important role in propulsion test facility design and development by assessing risks, identifying failure modes and predicting anomalous behavior of critical systems. This is true for facilities such as the proposed A-3 that will operate at low pressures in conjunction… More

In-space valves are required to provide precise mass flow control, wide throttling range and handle rapid on-off control. These requirements can result in significant unsteady, transient effects both on the fluid mass flow rate, as well as the torque required. However, there currently are no… More

Modeling of missile plume signature emissions play a crucial role in supporting system-oriented studies in a number of important areas related to detection and identification of the rocket motor during high altitude maneuvers. Examples of these areas include early warning systems, post launch… More

The noise from the turbulent, hot, supersonic jets at take-offs and landings as well as high-Mach cruise at altitude dominates noise emanating from other powerplant components and has significant safety implications for launch personnel, as well as environmental impacts of noise pollution around… More

A new chemical kinetics model and database will be developed for aerothermodynamic analyses on entry vehicles. Unique features of this model include (1) the ability to model chemical kinetics in highly nonequilibrium flows at high altitudes, (2) the ability to predict nonequilibrium dissociation… More

Instabilities associated with fluid handling and operation in liquid rocket propulsion systems and test facilities usually manifest themselves as structural vibrations and may cause structural damage such as the cracks observed in the space shuttle hydrogen feed liners. While the source of the… More

Our Phase I program will extend and validate a high-speed engineering transitional model (ETM) using new CUBRC data sets (such as HIFIRE-1) of interest to the Air Force. The ETM is responsive to tunnel noise and wall heating, and predicts the overshoot in heat transfer observed in transitional data.… More

Control and management of cryogenic propellant tank pressures in low gravity is an important technical challenge to overcome for future long duration space missions. Heat leaking into the propellant tanks leads to self-pressurization of the tank due to vaporization. Advanced techniques such as… More

Characteristics of missile plume signature emissions have a great potential to enhance defensive capabilities in a number of important areas related to Ballistic Missile Defense Systems (BMDS). Supporting MDA's engineering applications related to missile typing, discrimination, tracking, algorithm… More

This proposal is focused on the development of a comprehensive aero-acoustic toolkit that can predict acoustic signatures of tactical projectiles. Development will focus on identification of noise generation mechanisms and their spectral content, propagation of the noise through non-uniform media… More

The program focuses on turbulence modeling enhancements for predicting hypersonic interceptor base flows, using existing benchmark data sets. Unified kε and algebraic stress (EASM) turbulence models, shown to adequately simulate fundamental high-speed jet data sets and now being validated with… More

The F-35 main weapons bay experiences severe acoustic loading when exposed to the freestream. The severity and attenuation of this loading is exacerbated by the very complex geometry of the weapons bay and the highly non-uniform approach flow. This extremely harsh aeroacoustic environment can also… More

The problem of interest is the development of a physics based model for conducting high-fidelity simulation of afterburning munitions, which are unique in that that they contain solid and/or liquid fuels that continue burning after the initial detonation to raise the temperature, enhance the… More

In the Phase I program, we will design an experiment/test article, and test/validate instrumentation and diagnostics, to be used to obtain plasma properties about a hypersonic vehicle having characteristics and features of the RAM-C flight vehicle. The test model is to be installed and tested in the… More

Characteristics of missile plume UV/Visible emissions & RCS have a great potential to enhance defensive capabilities in several areas related to Ballistic Missile Defense Systems (BMDS). Supporting MDA's engineering applications related to missile typing, discrimination, tracking, algorithm… More

The innovation in this proposal relates to the use of a generalized framework for prediction of RCS that utilizes a common procedure for computing the signature from a hardbody and its associated plume. The RCS methodology is based on a first principles approach to the solution of the Maxwell's… More

The noise from the turbulent, hot, supersonic jets at take-offs and landings as well as high-Mach cruise at altitude dominates noise emanating from other powerplant components and has significant safety implications for launch personnel, as well as environmental impacts of noise pollution around… More

Solution errors are inherent in any Computational Fluid Dynamics (CFD) simulation. Systematic identification, reduction, and control of these various error sources is crucial if the results of CFD simulations are to be trusted for design and performance assessment of air vehicles. While grid… More

The technical objective of this program is to develop a fast running, subgrid scale turbulence-chemistry interaction model for large-eddy simulation (LES) of aircraft combustors and augmentors that can accurately capture critical phenomena such as extinction and re-ignition effects. To accurately… More

The development of diagnostic techniques to simultaneously measure store trajectories and instantaneous flow state during store dispense at high speeds (Mach 2.0-5.0) from weapons bays is proposed. In Phase I of the proposed effort we will evaluate two different techniques for this purpose. The… More

Instabilities associated with the operation of liquid rocket propulsion systems and test facilities usually manifest themselves as structural vibrations and may cause structural damage. While the source of the instability is directly related to the performance of a component such as a turbopump, the… More

This proposal will lead to the development of a comprehensive aero-acoustic toolkit for predicting the acoustic signatures of tactical projectiles. Development will focus on identification of noise generation mechanisms and their spectral content, propagation of the noise through non-uniform media,… More

The program focuses on turbulence modeling enhancements for predicting coupled jet interaction baseflows. Unified kε turbulence model, and varied extensions that provide for scalar fluctutation models (SFM), baroclinic torque effects, realizability constrainst, vorticity/strain non-equilibrium… More

The Phase II program concentrates on improving computational capabilities for analyzing hypersonic missile base flow configurations by utilizing state-of-the-art experimental data and complementary LES data to support development and validation of RANS turbulence models for propulsive base flows.… More

This program focuses on the upgrade and validation of advanced turbulence models for the analysis of transpiration in high speed, aero-propulsive flows with and without combustion effects. A major upgrade involves the extension of scalar fluctuation models calibrated for fuel/air mixing to treat… More

The program focuses on the development of a unified design and optimization framework for hypersonic scramjet propulsive flowpaths. Preliminary design tools utilizing inverse ray tracing and characteristic techniques, as well as CFD codes containing advanced turbulence and chemical kinetic models… More

The proposed Phase I effort involves the formulation of innovative technical approaches for accurately simulating the transient power-on separation event for a two stage, supersonic/hypersonic missile. Our starting point for analyzing power on missile stage separation involves the use of both… More

Innovative approaches to make direct measurements of thrust/drag forces on scramjet inlets will be designed, constructed, and demonstrated in this Phase I program for use in hypersonic shock tunnel facilities. Two force measurements will be made. The first is a local skin friction measurement, that… More

The noise from the turbulent, hot, supersonic jets at take-offs and landings dominates noise emanating from other powerplant components and has significant safety implications for launch personnel, as well as by the integrity of the structural components of the deck itself. With the impending… More

CRAFT Tech and the research group at the Advanced Aero-Propulsion Laboratory of Florida State University have worked on the jet noise problem and its control for nearly a decade in highly interdisciplinary teams. Leveraging our considerable expertise, facilities that were specifically designed for… More

New high-efficiency, low-emission, fuel-flexible gas turbine designs will operate at fuel lean conditions near the flame blow-out limit. To maintain high efficiency and flame stability under these conditions, a detailed knowledge of the flame dynamics will be required from both experimental and… More

The uncertainty quantification methods developed under this program are designed for use with current state-of-the-art flow solvers developed by and in use at NASA. The Phase I program demonstrated the CRISP CFD<SUP>REG</SUP> error quantification and reduction code with simulations… More

An orifice element is commonly used in liquid rocket engine test facilities either as a flow metering device, or to provide a large reduction in pressure over a very small distance in the piping system. While the orifice as a device is largely effective in stepping down pressure, it is also… More

Current combustor design simulations aimed at reducing greenhouse gas emissions and improving fuel-lean combustion have entailed using large amounts of dedicated CPU resources for extended time periods due to the expense of solving detailed, strongly-coupled, chemical kinetic models. Such models… More

Pyrotechnically actuated valves are triggered on or off by firing an explosive charge that rapidly releases large amounts of high-pressure, gas. Pyrovalves are generally used for critical safety functions in almost all liquid and solid rocket systems and are designed to be fail-proof and provide… More

The proposed SBIR Phase I & II programs will lead to the validation of a state-of-the-art Large Eddy Simulation (LES) model, coupled with a Ffowcs-Williams-Hawkings (FW-H) farfield acoustic solver, for supporting the development of advanced engine concepts, including innovative flow control… More

New high-efficiency, low-emission, fuel-flexible gas turbine designs will operate at fuel lean conditions near the flame blow-out limit. To maintain high efficiency and flame stability under these conditions, a detailed knowledge of the flame dynamics will be required from both experimental and… More

ABSTRACT: Our Phase II program concentrates on extending, rectifying, and validating the ETM engineering transition model for 3D flows. ETM solves PDE"s for both transition onset and intermittency and has full 3D capabilities, shown to generate swept onset curves and variable transitional… More

An innovative approach for incorporating the coupled interaction between a ship airwake and rotor downwash in real-time dynamic interface simulations is proposed. The approach will use a database of high-fidelity ship-alone and coupled rotor-ship airwake CFD simulations to train an artificial neural… More

This proposal deals with the extension of physics in CFD codes to permit their more accurate and reliable analysis of transient missile jet/exhaust interactions. Such interactions include those associated with divert jet firings and with stage-separation, and their analysis is complicated by the… More

One of the persistent problems affecting the aerodynamic performance of rotorcrafts is retreating blade stall that results in large pitching moments and hazardous control situations. Our primary goal is the development of an unsteady design optimization framework that can be applied to refine… More

Accurate and efficient modeling of rotorcraft flowfields is challenging due to a combination of unsteady flow dynamics and a large disparity in Mach numbers. Preconditioning techniques used to alleviate numerical stiffness from low Mach numbers in steady flows have not performed as well in unsteady… More

The program focuses on CFD modeling requirements for predicting Multiple Reaction Control Jet (MRCJ) plume flowfields for hypersonic interceptors. Unified k & #949; turbulence model, and varied extensions that provide for scalar fluctutation models (SFM), baroclinic torque effects,… More

Modeling of missile plume signature emissions play a crucial role in supporting system-oriented studies in a number of important areas related to detection and identification of the rocket motor during high altitude maneuvers. Examples of these areas include early warning systems, post launch… More

Characteristics of missile plume signature emissions have a great potential to enhance defensive capabilities in a number of important areas related to Ballistic Missile Defense Systems (BMDS). Supporting MDA"s engineering applications related to missile typing, discrimination, tracking,… More

Characteristics of missile plume RCS have a great potential to enhance defensive capabilities in several areas related to Ballistic Missile Defense Systems (BMDS). Supporting MDA"s engineering applications related to missile typing, discrimination, tracking, algorithm development, etc. requires… More

Characteristics of missile plume UV/Visible emissions & RCS have a great potential to enhance defensive capabilities in several areas related to Ballistic Missile Defense Systems (BMDS). Supporting MDA"s engineering applications related to missile typing, discrimination, tracking, algorithm… More

ABSTRACT: The technical objective of this program is to develop a fast running, subgrid scale turbulence-chemistry interaction model for large-eddy simulation (LES) of aircraft combustors and augmentors that can accurately capture critical phenomena such as extinction and re-ignition effects. To… More

The proposed effort will conduct the development of the HSSS-DAT (High Speed Store Separation Data Acquisition Technique) System for simultaneously measuring store trajectories and instantaneous flow state during store dispense at high-speeds from weapons bays. CRAFT Tech & NCPA will complete… More

Our proposal involves the formulation and development of innovative technical approaches for accurately simulating the transient power-on separation event for a multi stage, supersonic/hypersonic missile. As part of this Phase II effort we will undertake the development and validation of a time… More

Our Phase II program will provide for the design, fabrication, and testing of skin friction gauges and force measurement modules that will operate in a hypersonic scramjet propulsive flowpath with hydrogen/air combustion. Gauges will be installed in the CUBRC Combustion Duct and a test matrix… More

The program focuses on turbulence modeling enhancements for predicting coupled jet interaction baseflows. Unified ke turbulence model, and varied extensions that provide for scalar fluctutation models (SFM), baroclinic torque effects, realizability constrainst, vorticity/strain non-equilibrium… More

Our proposal addresses the high fidelity modeling of transient rocket exhaust plumes in a static test environment. Static testing provides a practical means of obtaining plume signature data to support model validation. However, existing CFD codes routinely used for plumes in flight cannot… More

An orifice element is commonly used in liquid rocket engine test facilities to provide a large reduction in pressure over a very small distance in the piping system. Orifice elements are used in propellant lines, feed systems, plume suppression systems and steam ejector trains. While the orifice as… More

The proposed SBIR Phase II program will lead to the validation of a state-of-the-art Large Eddy Simulation (LES) model, coupled with a Ffowcs-Williams-Hawkings (FW-H) farfield acoustic solver, for supporting the development of advanced engine concepts, including innovative flow control strategies… More

The design, development and staging of tests to certify liquid rocket engines usually require high-fidelity structural, fluid and thermal support analysis. These analyses are crucial to a successful engine test program since pressurization requirements, heat loads, cooling requirements and… More

Plume signature phenomenology plays an increasingly important role in the development of a wide variety of missile defense technologies, both at the tactical and strategic levels. With the emergence of recent threats, plume signature phenomenology is increasingly central to Missile Defense… More

Plume signature phenomenology plays an increasingly important role in the development of a wide variety of missile defense technologies, both at the tactical and strategic levels. With the emergence of recent threats, plume signature phenomenology is increasingly central to Missile Defense… More

The proposed Phase I effort involves the formulation of improved models to accurately simulate the particles that are present in rocket exhaust plume flowfields with the goal of obtaining improved plume signature predictions. While the modeling of the exhaust plume flowfield is a relatively mature… More

ABSTRACT: Next generation liquid rocket systems, envision novel designs for cryogenic turbopumps that exhibit high suction performance with low inlet pressures, operate at high tip speeds to reduce size and weight, and can be throttled over a wide range of low, off-design flow conditions where the… More

As air vehicle speeds increase, air breathing engine and inlet technology follow through concurrent supersonic performance requirements. The recent ability to build smaller supersonic engines has established a void in small air vehicle inlet capability. A solution to decrease the overall footprint… More

The noise from the turbulent, hot, supersonic jets at take-offs and landings dominates noise emanating from other powerplant components and has significant safety implications for launch personnel, as well as by the integrity of the structural components of the deck itself. With the impending… More

An innovative approach for incorporating the coupled interaction between a ship airwake and rotor downwash in real-time dynamic interface simulations is proposed. The approach employs a database of high-fidelity ship-alone and coupled rotor-ship airwake CFD simulations to train an artificial neural… More

The proposed Phase I effort involves the formulation of an advanced model for accurately simulating the post burn out effects in solid rocket motors. This all encompassing model will account for known physical phenomena such as pyrolysis, heat conduction, fluid dynamics, and radiative transport… More

One of the most persistent problems affecting the aerodynamic performance of rotorcrafts is retreating blade stall that results in large pitching moments and hazardous control situations. In this proposal our primary goal is the development of an unsteady design optimization framework that can be… More

The Phase II effort will unify advanced models for simulating post burn out effects in solid rocket motors (SRM"s), coupling fluid dynamic, radiative, and conductive heat transfer processes using innovative parallelization strategies. Complex processes such as surface pyrolysis and slag… More