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Unified Methodology for Simulation of Continuum and Rarefied Flows

Award Information

Department of Defense
Missile Defense Agency
Award ID:
Program Year/Program:
2010 / SBIR
Agency Tracking Number:
Solicitation Year:
Solicitation Topic Code:
MDA 08-034
Solicitation Number:
Small Business Information
Computational Sciences, LLC
8000 Madison Blvd., Suite D102-351 Madison, AL -
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Woman-Owned: No
Minority-Owned: No
HUBZone-Owned: No
Phase 2
Fiscal Year: 2010
Title: Unified Methodology for Simulation of Continuum and Rarefied Flows
Agency / Branch: DOD / MDA
Contract: w9113m-10-c-0085
Award Amount: $499,833.00


We propose to develop stand-alone computational modules for seamlessly extending the validity of continuum CFD codes into transitional and rarefied flow regimes. The modules will be designed for implementation in to existing legacy codes for use in the characterization of high altitude plume flows. The approach is based on a novel, regularized set of Navier-Stokes equations (RNS) that is extended to account for kinetic effects (intermediate Knudsen number, fluctuations) in the continuum approximation. RNS has several important features not found in classical NS equations that are of direct relevance in high altitude plume flows: (a) Natural accounting of both continuum and rarefied gas flow regimes; and (b) Kolmogorov-scale field fluctuations resulting from a mathematical model that accounts for turbulent diffusion in a natural manner that allows direct simulation of phenomena such as laminar-turbulent transition and wall slip effects. Phase I has completed the development of stand-alone, computational module prototypes incorporating a simplified version of the RNS approach. The modules were connected to a characteristics-based high order compressible flow code with particle transport capabilities, and an unstructured finite-element code, and were successfully exercised and evaluated for a model problem that contained features of both continuum and rarefied flows. Phase II will complete the development of the modules, provide a detailed comparison to Navier-Stokes results for low and high altitude flow regimes, identify the parameter region where the approach is advised, and provide connections to plume signatures sponsored and managed by the MDA/DES modeling and simulation effort.

Principal Investigator:

Edward J. Kansa
Staff Scientist

Business Contact:

Tatiana Shvetsova
Business Officer
Small Business Information at Submission:

Computational Sciences, LLC
8000 Madison Blvd STE D102 Madison, AL 35758

EIN/Tax ID: 900191003
Number of Employees:
Woman-Owned: No
Minority-Owned: No
HUBZone-Owned: No