شبيه سازي مستقيم جريان جت دو بعدي مغشوش به روش تفاضل محدود فشرده

Direct Numerical Simulation of 2D Forced Jet using the Compact Finite Difference Method

Navier-Stokes equations for two dimensional jet flows are solved using direct numerical simulation. The length scale and the velocity scale of jet flow at the inlet boundary of computational domain are used as two characteristics to define the jet Reynolds number. These two characteristics are jet half-width and centerline velocity. Governing equations are discretized in streamwise and cross stream directions using a sixth order compact finite difference scheme and a mapped compact finite difference method, respectively. Cotangent mapping of y = -ficot(srf) is used to relate the physical domain of v to the computational domain of f . The compact third order Runge-Kutta method is used for time-advancement of the simulation, convective outflow boundary condition is employed to create a non-reflective type boundary condition at the outlet. An inviscid Stuart flow and a completely viscose solutions of Navier Stokes equations are used for the verification of numerical simulations. Results for perturbed jet flow in self-similar coordinates were also investigated which indicate that the time-averaged statistics for velocity, vorticity, turbulence intensities and Reynolds stress distribution tend to collapse on top of each other at flow downstream locations. Keywords: 2D Jet Flow, Compact Finite Difference, Jet Half-width. Jet Centerline