- **Main CFD Forum**
(*http://www.cfd-online.com/Forums/main/*)

- - **Boundary Condition**
(*http://www.cfd-online.com/Forums/main/96671-boundary-condition.html*)

Boundary ConditionHello. I have a question.
I'm reading the paper. This is "Application of a Fractional-step Method to Incompressible Navier-Stokes Equations" of Kim and Moin. They introduced two Boundary Conditions of U^hat. One is U^hat=U^n+1. The other is U^hat=U^n+1+dt*G(phi^n). But, I don't understand the latter case. Since G(phi^n)*dt=U^oldhat - U^n, U^hat=U^n+1+dt*G(phi^n)=U^n+1+U^oldhat - U^n. Thus, U^hat=U^oldhat. Because, U^n+1- U^n=0 on the boundary. Then, what is U^oldhat? I can't compute U^oldhat on the boundary. Please, help me. What's wrong? ps : 'G' means gradient. 'hat' is about velocity. |

All times are GMT -4. The time now is 01:21. |