CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   CFX (http://www.cfd-online.com/Forums/cfx/)
-   -   coefficient drag (http://www.cfd-online.com/Forums/cfx/76190-coefficient-drag.html)

JEHERZ May 17, 2010 14:52

coefficient drag
 
hello

I am new to CFD, conducted an analysis of flow around a vehicle, I want to determine the coefficient of drag and lift

the speed is in the z-axis direction, is appropriate to draw "Force Z" in the body of the vehicle and use the maximum value and apply it to find the drag coefficient.

such as graphing the drag coefficient?

which method should I take?

need help!!!!:confused::confused:

thanks

ghorrocks May 17, 2010 18:39

What do you mean by the maximum value of the force Z? The force probably is not steady so the force Z will not be constant - unless you have managed to get a turbulence model to average all the flow back to a steady state, which is unlikely to be accurate.

JEHERZ May 25, 2010 08:38

Plot coefficient drag??
 
My question is how to plot the drag coefficient.

Apply this formula:
force_z()@BODY / (0.5*density*Velocity^2*Area)

I'm new to CFD, I can not plot, I have to do?

Sorry my English is not very good

many thanks:confused::(

ghorrocks May 25, 2010 19:09

Define a monitor point with the CEL expression. Then you can see how the drag coefficient moves as the run progresses. Or you can do it in CFD-Post.

JEHERZ February 9, 2012 04:33

How do you do the CEL expression??

or

How could do it in CFD-post?

I can't do this expression, I need you help me, please!!!!

ghorrocks February 9, 2012 07:28

Put the expression posted above in as a monitor point in a solver run, or put it into the function calculator in CFD-Post.


All times are GMT -4. The time now is 06:14.