skip to main content

SciTech ConnectSciTech Connect

Title: A direct numerical simulation-based investigation and modeling of pressure Hessian effects on compressible velocity gradient dynamics

The pressure Hessian tensor plays a key role in shaping the behavior of the velocity gradient tensor, and in turn, that of many incumbent non-linear processes in a turbulent flow field. In compressible flows, the role of pressure Hessian is even more important because it represents the level of fluid-thermodynamic coupling existing in the flow field. In this work, we first perform a direct numerical simulation-based study to clearly identify, isolate, and understand various important inviscid mechanisms that govern the evolution of the pressure Hessian tensor in compressible turbulence. The ensuing understanding is then employed to introduce major improvements to the existing Lagrangian model of the pressure Hessian tensor (the enhanced Homogenized Euler equation or EHEE) in terms of (i) non-symmetric, non-isentropic effects and (ii) improved representation of the anisotropic portion of the pressure Hessian tensor. Finally, we evaluate the new model extensively by comparing the new model results against known turbulence behavior over a range of Reynolds and Mach numbers. Indeed, the new model shows much improved performance as compared to the EHEE model.
Authors:
; ;  [1]
  1. Department of Applied Mechanics, Indian Institute of Technology Delhi, Delhi 110016 (India)
Publication Date:
OSTI Identifier:
22403205
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Fluids (1994); Journal Volume: 26; Journal Issue: 12; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ANISOTROPY; COMPRESSIBLE FLOW; COMPUTERIZED SIMULATION; FLUIDS; IDEAL FLOW; LAGRANGIAN FUNCTION; NONLINEAR PROBLEMS; REYNOLDS NUMBER; TENSORS; THERMODYNAMICS; TURBULENT FLOW; VELOCITY