The two-dimensional spatial evolution of a mixing layer has been studied by means of the Direct Numerical Simulation (DNS). A sixth order compact finite difference scheme has been used for the spatial derivatives. The Navier-Stokes equations are advanced in time by means of a fourth order Runge-Kutta scheme. The computational code has been parallelized by means of standard OpenMP directives. By using this technique, a parallel efficiency of 0.83 has been achieved on an AlphaServer ES40. The computations show the phenomena of roll up and vortex pairing. In the region of fully turbulent regime, the vorticity thickness growth rate has been computed and the results are comparable with those obtained by experimental measurements available in literature.
Direct Numerical Simulation of Turbulent Free Shear Flows
VIGGIANO, ANNARITA;MAGI, Vinicio
2001-01-01
Abstract
The two-dimensional spatial evolution of a mixing layer has been studied by means of the Direct Numerical Simulation (DNS). A sixth order compact finite difference scheme has been used for the spatial derivatives. The Navier-Stokes equations are advanced in time by means of a fourth order Runge-Kutta scheme. The computational code has been parallelized by means of standard OpenMP directives. By using this technique, a parallel efficiency of 0.83 has been achieved on an AlphaServer ES40. The computations show the phenomena of roll up and vortex pairing. In the region of fully turbulent regime, the vorticity thickness growth rate has been computed and the results are comparable with those obtained by experimental measurements available in literature.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
