Post your exact expression here, along with all the expressions it depends on.

=areaAve(0.5*Density *(u^2+v^2+w^2))@Default Domain Default

strange thing is that i have a speed of 15 m/s so u^2 should be 225

but i get 266.956 in joule kg^1

so am i not getting things?

Hi Jan,

The expression looks fine, except as I mentioned earlier in this thread, you should not be calculating the dynamic pressure at a wall; it should be taken at your inlet.

As for the return value of (u^2+v^2+w^2), the units are correct, 1 [Joule/kg] = 1 [m^2/s^2]. If you look at v and w in the same region you'll find that they have a small value on the order of 6 m/s.

The expression is fine as is and works for me here. I suggest you contact customer support if you are still having issues.

Regards, Robin

hi robin

thanks for the answer but i am still puzzeled for the speed since its totaly off

so where sould i take the speed wich i am starting with that is 15 m/s normaly you would say velocity u but it give me more then 16 m/s

every where i try to get the good speed wich is as i said 15 m/s i get more the 16m/s on wall or outlet or inlet keep geeting the wrong speed

i double checked i start with 15 m/s so.....................

If you have a constant velocity of 15 m/s at the inlet the development of boundary layers will force the flow to accelerate away from the wall, hence the higher velocity. If you want to use 15 m/s to calculate the dynamic pressure, just enter it explicitly.

-Robin