DNS/LES for NASA Aerodynamic Needs and Engineering Applications
NATIONAL AERONAUTICS AND SPACE ADMIN LANGLEY RESEARCH CENTER HAMPTON VA COMPUTATIONAL AND SIMULATION BRANCH
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While direct andor large eddy simulations are probably not going to be capable of predicting complex aerodynamic flow field themselves, the methodologies can and should be utilized to solve flow problems that replicate the essential dynamic features of the flill problem. In the near term, this may be the most useful role of such methodologies rather than as a substitute to the currently available RANS-type models. These simulation results can then be used to develop improved closure models for higher-order correlations that appear in the models for the Reynolds stress tensor. Within this framework, examples of complex aerodynamic flow fields including a high-lift system composed of a multi-element airfoil configuration and a scramjetramjet engine configuration were used to highlight the need for well chosen unit problems that would isolate the key dynamics associated with such flows. Currently, composite methodologies are appearing which attempt to utilize both the LES and RANS-type formulations. Formal and complete methods which correctly utilize these two formulations may need to satisfy some consistency requirements in order to insure that both the LES and RANS-type formulation will yield the same mean flow fields.
- Fluid Mechanics