Coefficient Cp
Dear all,
Hi, after simulating the flow motion around a vertical cylinder under steady current, I should caluculate the coefficient Cp to validate my model. As is known to all, the Cp of the stagnation line at the front side of the cylinder of different depth is below 1. But always the Cp I calculate is above 1. Here the book mention that Cp=(pp0)/(0.5*density*vo*vo), so how to pick datas of po and v0 in flow3d? poinlet boundary or developed pressure? voinlet velocity or developed velocity, constant or different in z direction? Or I should try another formular? pthe pressure of the grids near the surface of the cylinder? I have tried many times, but the Cp is still not correct. So anyone can tell me the best solution? PS. the model runs well I don't think there is any fatal error. 
1 Attachment(s)
Why always above 1?
I choosed pressure at the inlet boundary as po(developed). In addition, mean velocity or zdirectionchanged velocity is also used but still not solved. In experiment, Cp is smaller than 1. 
1 Attachment(s)
Here is the experiment picture

Quote:
Cp=(pip)/(p0p) Pi= circumferential pressure p0=stagnation pressure p= free stream pressure when tete=0 : pi=p0 :........... Cp=1 If your goal is estimation of drag coefficient, I suggest to you that you get darg force from software directly and then calculate drag coefficient. 
All times are GMT 4. The time now is 21:41. 