I have to simulate the wake behind a sinusoidal cylinder (3D) in fluent but I don't know how to make a model of sinusoidal cylinder in Gambit. Could you tell me how to do??? Please help me as soon as possible ! Thanks so much !!!

steps are like this:
[*]create sine curve from bunch of vertices[*] create the face of the cylinder[*] Extrude the face along the curve to create the desired cylinder

Now the question is how do you create the sine curve, here is the jou to create this, adjust to your likings

$i = 0 $imax = 360 $inc = 5 $j = 0 $A = 100 do para "$i" init 0 cond ($i.le.$imax) incr $inc $j = $A * SIN($i) vertex create coordinate $i $j 0 enddo $vertices = LISTENTITY(t_ve) edge create nurbs $vertices interpolate

Please show me in more detail !!!

humm more detail,

i think you are little new to gambit, so here it goes:[*] start gambit[*] file->Run Journal (here run the journal, it shall create you the model

Now about the journal , you can copy the following text into a file, say , sine.jou, save it, and then run it as mentioned above, this shall create you the full sine cylinder. The journal

$i = 0 $imax = 360 $inc = 5 $j = 0 $A = 90 do para "$i" init 0 cond ($i.le.$imax) incr $inc $j = $A * SIN($i) vertex create coordinate $i $j 0 enddo $vertices = LISTENTITY(t_ve) edge create nurbs $vertices interpolate face create radius 30 yzplane circle volume create translate "face.1" onedge "edge.1"

Off course the above journal will make the sine curve along x-axis, as y = A sin(x), i put the value A = 100, and x from 0 to 180 degs, The radius of the face i have chosen 30 , you can chose based on what you like. If you do not understand much from the jou file, you can run each line as command from gambit command prompt, it will create it step my step and you will be able to see how the cylinder was made.

oh, can u give me your email address, Zxarr???. I will send you some images of the model. It's not a nomal sine cylinder, Zxarr! Reply me soon!!! Thank you so much, Zxarr!

my email address: mrquangngoc@gmail.com Reply me soon!!!Thanks

my email is zxaar@yahoo.com

i know it is not normal (face normal is not aligned with the curve), but that can be easily adjusted by rotating the face to proper angles, and that angle you can calculate from the first two vertices you have created)

well decided to do it myself, and here is the new journal that rotates the face to match it normal

$x0 = 0 $y0 = 0 $z0 = 0 $x1 = 0 $y1 = 0 $z1 = 0 $phi = 0 $i = 0 $imax = 360 $inc = 5 $j = 0 $A = 90 $y1 = $A * SIN($inc) $x1 = $inc $phi = ATAN( $y1 / $x1 ) do para "$i" init 0 cond ($i.le.$imax) incr $inc $j = $A * SIN($i) vertex create coordinate $i $j 0 enddo $vertices = LISTENTITY(t_ve) edge create nurbs $vertices interpolate face create radius 30 yzplane circle face move "face.1" dangle $phi vector 0 0 1 origin 0 0 0 volume create translate "face.1" onedge "edge.1"

But in the last command, gambit gives this error: ERROR: ACIS error 71006 : The chain to be swept is parallel to the path It seems that it won't allow you to make the sine cylinder when the face is normal. I would suggest that send this journal to your fluent support and ask them the solution or a way around. I could not think of any at the moment.

Try hard, Zxaar. I really need your help. The problem is very important to me. Goodluck to you !!!

actually if i split the edge with u=0.25 then for the first part, it creates the volume, but next part it again gives the same error. This week i am very busy, so can't promise anything, but i will try to think something, Meanwhile you spend sometime with gambit, it will help.

can you give me the exact dimensions of the sine cylinder you want, i just meshed it on hypermesh, i probably will be able to provide the mesh. (please mention what mesh size (in no. of cells)you wish to have )