inlet condition in preconditioning method

ricklee

hi all:

My code is development to solve the compressible flow. I used Weiss-Smith version of the preconditioning matrix to slove the low speed flow and add dual time stepping in my code. Besides,I also used LES to deal the viscous terms.

In inlet condition I set a uniform flow in the inlet at the channel. But the result is not reasonable. The speed in grid front of the inlet is too slow. For example,I set the inlet 10m/s.The speed front of the inlet is only 5m/s. Besides, the speed is also appear "shock".

channel ------------------------------------------------ inlet(10m/s)-->5m/s-->6m/s oulet ------------------------------------------------

Can give me some idea about my problem?