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raziman September 12, 2008 20:08

urgent-harmonic motion
hello... my title is study on laminar pulsed flow in microchannel in rectangular... i need to run it in fluent. just now i dont know the right equation for harmonic motion to set as boundary condition...

can u all help me.. i need to know my boundary condition.... for inlet, oulet n wall.. plz this is urgent

Chin Fook September 12, 2008 20:29

Re: urgent-harmonic motion
You need an UDF to define the velocity inlet in the form of u(x)=A*Sin(w*t) where A is the motion's amplitude, w is the frequency (=2*pi*f) and t is the time.

raziman September 12, 2008 20:44

Re: urgent-harmonic motion
ook tq for review my problem... udf is user define right??? do u have a tutorial that similiar with that...

Chin Fook September 12, 2008 21:48

Re: urgent-harmonic motion
Try to look into Fluent's documentation

raziman September 12, 2008 23:34

Re: urgent-harmonic motion
tq.... ok. i appreciate that. that is simple harmonic motion (x)=A*Sin(w*t)?? plz explain about : w is the frequency (=2*pi*f) tq..

Chin Fook September 14, 2008 22:28

Re: urgent-harmonic motion is v(t)=A*Sin(w*t) means the speed is in the function of time or it can be replaced with x(t) denoting the displacement. A as mentioned earlier is the amplitude of the harmonic motion and w is the angular frequency denoted by w=2*pi*f. when we times with t (w*t) that simply leave us with only the angles, 2*pi and the equation could simply means v(t)=A sin (theta). In this case the "theta" refers to angular means of harmonic motion (a complete cycle would be 2*pi). Hope that helps.

raziman September 15, 2008 02:28

Re: urgent-harmonic motion
tq.... that help a lot... i appreciate your help... hppe next time i got the problem you cn help me.. thank u

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