User Function

racerdude777 · April 7, 2011, 16:04

I'm modeling a 3-D wing in a wind tunnel and am looking to oscillate the flow direction in a sinusoidal fashion. I am looking to use a simple user function to accomplish this but Star-CCM+ can't compile it. Can somebody take a look and shed some light on whats wrong with it? Thank you.

First Code:
($Time > 0) :
$$Velocity[0] = 24.218*COS*(0.2094395+0.174533*SIN*((0.2079*$Time) ));
$$Velocity[1] = 24.218*SIN*(0.2094395+0.174533*SIN*((0.2079*$Time) ));
$$Velocity[2] = 0;

Second Code:
($Time > 0)? [24.218*COS*(0.2094395+0.174533*SIN*((0.2079*$Time) )), 24.218*SIN*(0.2094395+0.174533*SIN*((0.2079*$Time) )), 0] : [0,0,0])

racerdude777

f-w · April 7, 2011, 17:17

Try:

[($Time > 0) ? 24.218*cos(0.2094395+0.174533*sin(0.2079*$Time)) : 0, ($Time > 0) ? 24.218*sin(0.2094395+0.174533*sin(0.2079*$Time) ) : 0, 0]

abdul099 · April 14, 2011, 02:58

$$Velocity[x] with x = 0,1,2 (from the first code) adresses the velocity field generated by the solver. You can not assign any values to one of the default field functions, so the statement "$$Velocity[0] = " can not work.
In general, your second code should work, but there are some * too much between the sin and cos functions and the following brackets. Even on your calculator, you don't type "sin * (5*PI)", you type sin(5*PI).

Try
($Time > 0)? [24.218*COS(0.2094395+0.174533*SIN((0.2079*$Time) )), 24.218*SIN(0.2094395+0.174533*SIN((0.2079*$Time) )), 0] : [0,0,0])

April 7, 2011, 16:04	User Function	#1
racerdude777 New Member Ryan Join Date: Sep 2010 Posts: 6 Rep Power: 15	I'm modeling a 3-D wing in a wind tunnel and am looking to oscillate the flow direction in a sinusoidal fashion. I am looking to use a simple user function to accomplish this but Star-CCM+ can't compile it. Can somebody take a look and shed some light on whats wrong with it? Thank you. First Code: ($Time > 0) : $$Velocity[0] = 24.218COS(0.2094395+0.174533SIN((0.2079$Time) )); $$Velocity[1] = 24.218SIN(0.2094395+0.174533SIN((0.2079$Time) )); $$Velocity[2] = 0; Second Code: ($Time > 0)? [24.218COS(0.2094395+0.174533SIN((0.2079$Time) )), 24.218SIN(0.2094395+0.174533SIN((0.2079$Time) )), 0] : [0,0,0]) racerdude777

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April 7, 2011, 17:17		#2
f-w Senior Member Join Date: Apr 2009 Posts: 154 Rep Power: 17	Try: [($Time > 0) ? 24.218cos(0.2094395+0.174533sin(0.2079$Time)) : 0, ($Time > 0) ? 24.218sin(0.2094395+0.174533sin(0.2079$Time) ) : 0, 0]

April 14, 2011, 02:58		#3
abdul099 Senior Member Join Date: Oct 2009 Location: Germany Posts: 636 Rep Power: 21	$$Velocity[x] with x = 0,1,2 (from the first code) adresses the velocity field generated by the solver. You can not assign any values to one of the default field functions, so the statement "$$Velocity[0] = " can not work. In general, your second code should work, but there are some * too much between the sin and cos functions and the following brackets. Even on your calculator, you don't type "sin * (5PI)", you type sin(5PI). Try ($Time > 0)? [24.218COS(0.2094395+0.174533SIN((0.2079$Time) )), 24.218SIN(0.2094395+0.174533SIN((0.2079$Time) )), 0] : [0,0,0])