حل معادلات سه بعدي اويلر براي جريان مافوق صوت با استفاده از روش هاي صريح و ضمني رو

A 3-DIMENTIONAL EULER SOLUTION FOR SUPERSONIC FLOWS USING ROEʹS METHOD WITH EXPLICIT AND IMPLICIT TECHNIQUES

In this paper a 3-D Euler code for solving supersonic flows has been developed. The new code uses several numerical algorithms for space and time discretization. Roeʹs method is used for discretizing the convective terms. Explicit and implicit time marching techniques and a finite volume space discretization are used. The computational model is applied to a hypersonic flow at Mach 7.95 around a cone at different incidence angles. The circumferential pressure distribution is compared with the experimental data. The cases of supersonic flows with Mach number 3 around a secant - ogivo with incidence angles of 6° and 10" are also studied. The circumferential pressure distributions are compared with the experimental data and good agreement is obtained in the location that the separation zone is not large. At the Lee-ward region of the secant - ogive near to the end of the body, especially at incidence angle of 10" the accuracy of numerical result decreases and a Navier-Stokes code should be used to get a better result. The cross-sectional Mach number contours are also presented. It is shown that in this case in addition to the outer shock, a cross-flow shock wave is also present at the incidence angle of 10°. This code has the capability to solve unsteady flow also and the viscous terms can be added easily to prepare a Navier-Stokes code.