OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Trusted AI and Autonomy;Integrated Sensing and Cyber;Integrated Network System-of-Systems
The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with the Announcement. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws.
OBJECTIVE: To increase the fidelity of turbine aerodynamic predictions performed during the design cycle via the adoption of Large Eddy Simulation techniques that are enabled by Graphical Processing Unit (GPU) architectures to achieve unprecedented turnaround times for the completion of calculations
DESCRIPTION: Large Eddy Simulation (LES) represents a substantial increase in the fidelity of viscous modeling used in turbomachinery design. LES is an essential capability for the accurate prediction of flows over Low Pressure Turbine (LPT) airfoils at conditions that are consistent with high-altitude Unmanned Air Systems (UAS). Successful application of LES in the design cycle of an LPT is expected to yield geometries that have unprecedented levels of lift, work, and resistance to flow separation at high altitude conditions. This would lead to substantial reductions in engine weight, length, and cost while at the same time enabling increased engine fuel-efficiency as well as increased range, endurance, and ceiling for an UAS. However, the grid topologies required to obtain accurate LES simulations of LPT flowfields make it impossible to complete such calculations in a timely manner for design purposes. Typically, LES simulation is a research tool used to increase the understanding of turbomachinery flow physics, and it is not currently used in the turbine design cycle at any Original Equipment Manufacturer for jet engines due to the large calculation times required by state-of-the-art, commercially available flow solvers. Fortunately, the application of advanced computer architectures incorporating Graphical Processing Units (GPUs) to flow solvers for turbomachinery holds the promise of reducing the turnaround time required for such flow simulations to a level consistent with design iterations. Accordingly, an SBIR project is proposed to apply GPU architectures to an available flow solver (or flow solvers) and to demonstrate the efficacy of that capability for design purposes. Long range, high endurance Unmanned Air Systems are an essential component of an effective Tactical Air Dominance, NGAD Family of Systems capability. This effort is in keeping with the Air Superiority 2030 Flight Plan which states that “development efforts for … persistent ISR capabilities will focus on multi-domain alternatives for placing the right sensor in the right place at the right time.” Increases in turbine aero-performance at high altitude lead directly to increased range and endurance for Unmanned Air Systems, and operationally this leads to increased time on station. Finally, this effort is an excellent illustration of the intent of the S&T 2030 document which states that “the Air Force will increase focus on and strengthen relationships with … industry” and that “partnerships will expand and strengthen to draw technology out of government, university, and industry laboratories and mature it into transformational operational capabilities.”
PHASE I: As this is a Direct-to-Phase-II (D2P2) topic, no Phase I awards will be made as a result of this topic. To qualify for this D2P2 topic, the Government expects the applicant to demonstrate feasibility by means of a prior “Phase I-type” effort that does not constitute work undertaken as part of a prior SBIR/STTR funding agreement. Accordingly, to qualify for consideration under this D2P2 topic, applicants must have accomplished the following in a prior "Phase I-type" of effort: Perform initial Large Eddy Simulation code development along with proof-of-concept calculations and a demonstration of potential improvements in turnaround time through use of GPU architectures on a Low Pressure Turbine airfoil of interest to the USAF. An example airfoil of interest is the well known Pack B airfoil that is widely distributed throughout industry, government, and academia and is readily found in the open literature.
PHASE II: Perform code development and demonstration of net improvements in turnaround time through use of GPU architectures for Large Eddy Simulations of Low Pressure Turbine stages. Perform code validation studies against datasets defined by both the USAF and an Original Equipment Manufacturer of turbine engines.
PHASE III DUAL USE APPLICATIONS: Commercialize and transition GPU-enabled LES code to tier 1, tier 2, and tier 3 OEMs for turbine engines and additional government agencies.
- Kerestes, J., Marks, C., Clark, J., Wolff, J., Ni, R-H., and Fletcher, N., 2023, "LES Modeling of High-Lift High-Work LPT Blades, Part II: Validation and Application," ASME Paper No. GT2023-101950.
KEYWORDS: Low pressure turbine; GPU computing; Large eddy simulation; Turbine design