Signal decay in les channel flow

pankaj saha

hi,

i am doing channel flow by LES. I am taking periodic b.c in streamwise direction. I am using re=210, nondimensionalize by, friction velocity and channel height. so, i am putting mean pressure gradint=2.0, a source term for, streamwise momentum equation.

My, initial condition is--u(x,y,z)=(1-y^8)+10*rand().

v,w=0.0

i am taking time signal, near the wall. at a yplus=12.

i saw, initially a good signal.then after, a time unit 9, the signal becomes disappear.

could anybody, have this experience..of simulating chhanel flow. please help me.

thanks in advance