chart problem please help

jayanth1990 · October 30, 2012, 06:17

hi guys i just did a aerodynamic analysis using cfx
i used inlet velocity as 16 m/s

i have obtained results such as drag and lift force, coefficent using suitable expressions.

in the post processor CFD POST
i just want a plot of the drag,lift forces vs velocity
and drag and lift coefficients vs velocity

when i try to do this im asked for a data series i create a line like the ones that are given in the tutorial but still

i am unable to choose these variables which i have defined as they do not appear in variable drop down list boX

When i check in the conservative variable box
another large list of variables appears but the ones i have defined are not to be found

another doubt is that it says Forces can be calculated only in planar areas , so can i give a plane as a data series

please do help me out im relatively new to cfx and i need the graph for a report which has to submitted as quick as possible

thank you

evcelica · October 31, 2012, 12:38

You have created expressions, but have you created variables from the expressions? that may help.

I don't think you can specify a plane as a data series. But if you think about it, of course a force has to be integrated over an area, but you can normalize it and plot pressure along your line instead of force (pressure = force per unit area)

What is the Velocity you are plotting against? I see you are running only 1 simulation.

October 30, 2012, 06:17	chart problem please help	#1
jayanth1990 New Member jayanth joseph Join Date: Aug 2012 Posts: 3 Rep Power: 14	hi guys i just did a aerodynamic analysis using cfx i used inlet velocity as 16 m/s i have obtained results such as drag and lift force, coefficent using suitable expressions. in the post processor CFD POST i just want a plot of the drag,lift forces vs velocity and drag and lift coefficients vs velocity when i try to do this im asked for a data series i create a line like the ones that are given in the tutorial but still i am unable to choose these variables which i have defined as they do not appear in variable drop down list boX When i check in the conservative variable box another large list of variables appears but the ones i have defined are not to be found another doubt is that it says Forces can be calculated only in planar areas , so can i give a plane as a data series please do help me out im relatively new to cfx and i need the graph for a report which has to submitted as quick as possible thank you

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October 31, 2012, 12:38		#2
evcelica Senior Member Erik Join Date: Feb 2011 Location: Earth (Land portion) Posts: 1,188 Rep Power: 23	You have created expressions, but have you created variables from the expressions? that may help. I don't think you can specify a plane as a data series. But if you think about it, of course a force has to be integrated over an area, but you can normalize it and plot pressure along your line instead of force (pressure = force per unit area) What is the Velocity you are plotting against? I see you are running only 1 simulation.