Triple Decomposition of Velocity Gradient Tensor in Compressible Turbulence

The decomposition of the local motion a fluid into straining, shearing, and rigid-body rotation is examined in this work for compressible isotropic turbulence by means direct numerical simulations. triple closely associated with basic reference frame (BRF), which extraction biasing effect shear maximized. In study, new computational inexpensive procedure proposed to identify BRF three-dimensional flow field. addition, influence compressibility effects on some statistical properties turbulent structures addressed. simulations are carried out Reynolds number that based Taylor micro-scale Reλ=100 various Mach numbers range from Mat=0.12 Mat=0.89. DNS database generated an improved seventh-order accurate weighted essentially non-oscillatory scheme discretize non-linear advective terms, eighth-order centered finite difference retained diffusive terms. One major findings analysis regions featuring strong rotations or straining motions highly spatially intermittent, while most exhibit moderately shearing absence motions. majority can be estimated if scaling laws case rescaled only considering solenoidal contributions.