CFD Online Discussion Forums

CFD Online Discussion Forums (
-   Main CFD Forum (
-   -   Free Stream condition (

shah January 8, 2007 11:35

Free Stream condition
What exactly mean by free stream condition? and what is the criteria for choosing it.

if I am calculting flow in a channel for internal flow case and flow past circular cylinder for external flow case . then what should be my free stream velocities and pressure.

My flow equation is 2d Navier stokes.


Mohamed January 10, 2007 14:58

Re: Free Stream condition
The inflow primitive values like M_in, P_in, T_in...are considered as free stream conditions to accelerate the convergence. Since the flow is affected in a small part of the domain(Otherpart remains freestream), this initial condition will work far better than zero initial condition.

Freestream condns are one of the best initial conditions to start the simulation. Since its a uniform value, finally you will get zero diffusion and zero acceleration. so LHS and RHS part of the N-S eqns become zero.

For channel flow and cylinder case, use inflow conditions as a freestream condn,,,,

Bye Mohamed

All times are GMT -4. The time now is 15:16.