Development of a Near-Wall Reynolds-Stress Closure Based on the Ssg Model for the Pressure Strain PDF Download

Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781723025662
Category :
Languages : en
Pages : 136

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Book Description
In this research, a near-wall second-order closure based on the Speziable et al.(1991) or SSG model for the pressure-strain term is proposed. Unlike the LRR model, the SSG model is quasi-nonlinear and yields better results when applied to calculate rotating homogeneous turbulent flows. An asymptotic analysis near the wall is applied to both the exact and modeled, equations so that appropriate near-wall corrections to the SSG model and the modeled dissipation-rate equation can be derived to satisfy the physical wall boundary conditions as well as the asymptotic near-wall behavior of the exact equations. Two additional model constants are introduced and they are determined by calibrating against one set of near-wall channel flow data. Once determined, their values are found to remain constant irrespective of the type of flow examined. The resultant model is used to calculate simple turbulent flows, near separating turbulent flows, complex turbulent flows and compressible turbulent flows with a freestream Mach number as high as 10. In all the flow cases investigated, the calculated results are in good agreement with data. This new near-wall model is less ad hoc, physically and mathematically more sound and eliminates the empiricism introduced by Zhang. Therefore, it is quite general, as demonstrated by the good agreement achieved with measurements covering a wide range of Reynolds numbers and Mach numbers. So, R. M. C. and Aksoy, H. and Sommer, T. P. and Yuan, S. P. Unspecified Center BOUNDARY CONDITIONS; CHANNEL FLOW; MATHEMATICAL MODELS; PRESSURE GRADIENTS; REYNOLDS STRESS; WALL FLOW; ASYMPTOTIC PROPERTIES; BOUNDARY LAYERS; MACH NUMBER; ROTATION; SHEAR STRESS; TURBULENT FLOW...