N13A-T009 TITLE: High Efficiency Computation of High Reynolds Number Flows

TECHNOLOGY AREAS: Ground/Sea Vehicles

ACQUISITION PROGRAM: Advanced Submarine Systems Development (NAVSEA 073R) and FNC – Towed Array

OBJECTIVE: The objective is to develop a computational capability for high Reynolds number flows that provides a significant improvement in computational efficiency over existing capabilities.

DESCRIPTION: The Navy seeks a computational capability for high Reynolds number flow(1) that provides a significant improvement in computational efficiency over existing software packages. Flows will be three dimensional, viscous, incompressible, with embedded solid obstacles(2). The capability must allow for inhomogenous media. While the software should take full advantage of the most recent high performance computing capabilities, high value will be placed on innovative algorithms that provide an inherent enhancement of computational efficiency.

Currently, the complexity of the problem that can be modeled is limited by the efficiency of the computation. In almost every case of interest, severe approximations must be made in order to accommodate the computations within even the most sophisticated computational resources. These approximations limit accuracy, introduce risk and uncertainty, decrease the robustness of the computations, and necessitate a highly educated and experienced work force to perform the analyses.

PHASE I: The company will develop an algorithm or set of algorithms which will provide a significant improvement in computational efficiency over existing approaches. The company will demonstrate the feasibility of the algorithm in meeting Navy needs and provide a Phase II development plan with performance goals and key technical milestones.

PHASE II: Based on the results of Phase I and the Phase II development plan, the company will implement the algorithm or algorithms into a prototype computational capability, and demonstrate its performance against a government-specified problem. Evaluation results will be used to refine the algorithm into a system that will meet Navy needs. The company will prepare a Phase III development plan to transition the technology to Navy use.

PHASE III: If Phase II is successful, the Navy will fund the company to extend the development into a user-friendly software package and to support the government-specified user community via documentation and training. Once the software has come into routine use within the user community, the company will be expected to maintain and update the software.

PRIVATE SECTOR COMMERCIAL POTENTIAL/DUAL-USE APPLICATIONS: High Reynolds number hydrodynamics computation is of interest in a very wide array of applications, including, to name just two examples, aircraft design and race-car development.

REFERENCES:
1) Ugo Piomelli and Elias Balaras, "Wall-Layer Models for Large-Eddy Simulations," Annu. Rev. Fluid Mech. 2002, 34:349–74

2) David A. Boger* and James J. Dreyer†, " Prediction of Hydrodynamic Forces and Moments for Underwater Vehicles Using Overset Grids," AIAA 2006-1148, (44th AIAA Aerospace Sciences Meeting and Exhibit, 9-12 January 2006, Reno, Nevada).