problem in writing CEL expressions for mesh motion
 

hello,

I am quite new in CFX . I need to get mesh deformed at boundaries using specified displacement mesh motion and thinking to input x and y components of displacement as CEL expression . my original equation is kind of fourier function and for example the x directional motion equation is x= 20.11+ 8.569 cos 7.854t+3.256 cos 7.854t+.....so on ...can anybody give me instruction that how to write this quation as expression correctly in boundary mesh motion specified displacement . I was trying to write it like xGlobal [mm] = 20.11[mm] + 8.596 [mm] *cos( 7.854 [radian s^-1] * t [s])+........so on.. but it gave error that suucessfully read 13 characters xGlobal [mm] then error detected at 20.11[mm] + 8.596 [mm] *cos( 7.854 [radian s^-1] * t [s])+... can anybody suggest how to write it correctly ... the motion is time dependent................ thanx for reading

tc

"suucessfully read 13 characters"
Which in your case would be "=". You dont need the equal sign, instead just type the expression like 20.11[mm] + 8.596 [mm] *cos( 7.854 [radian s^-1] * t [s]) in the input box.

hi

thanx a lot .....now the error message is gone....i think it has worked....but I have another question.......my model is actually a curve tube which i need to bend with respect to time in a periodic motion.....actually the radius of curvature will change sinusoidally ..now my question is the strategy i am planning to apply is like I have written the previous equations in the mesh motion options of x and y component which i guess will move the entire mesh and model with specified displacement......is my way fine to achieve this? if not can u suggest how to make that happen .......thanx again for ur helpful reply....

tc