Development of 2 D, 3D Direct Numerical Simulation Models and their validation

A numerical model for representation of turbulence in urban areas is developed by NIMR(National Institute of Meteorological Research). DNS_NIMR(Numerical model name: DNS(Direct Numerical Simulation)) computes three-dimensional, unsteady incompressible flows using a projection method. The model was developed by using a Navier-Stokes equation excluding thermal characteristics as a governing equation. By adapting several Poisson solvers, such as Gauss-seidel approach and Cholesky factorization approach, computing time was reduced. Computing memory was reduced as well by using sparse matrix. Numerical solutions for flows inside a driven cavity, over a backward-facing step, and a wall-mounted cube are presented and compared with experimental data and other numerical results. It seems that DNS_NIMR is competitive and more research is being done to improve the model.