Modelling of the turbulent energy decay based on the finite-difference and spectral methods

Abstract

The work deals with the modeling of turbulent energy using finite-difference and spectral methods. Simulation of the turbulent process is based on the filtered three-dimensional unsteady Navier-Stokes equations, for the closure of the main equation the dynamic model is used. The mathematical model is solved numerically, the equation of motion is solved by a finite-difference method, the equation for pressure is solved by spectral method. Also new algorithm for the numerical solution of the Poisson equation for finding pressure is developed. In the results of simulation, the change of turbulent kinetic energy over the time, the integral length scale, the change of longitudinal-transverse correlation functions are obtained, and longitudinal and transverse one-dimensional spectra are defined.