Total Velocity

salihovic · July 19, 2010, 15:12

Hi,

May be a stupid question?

I have U and V velocity,

I dont have total velocity (after loading data into tecplot from CFX output--cngs)

How can I obtain in tecplot total velocity and make contour of it?

In Equation it seems I am allowed to only define scalars?

Magnitude I can define, but I want to visualise also some flow reversal,

total velocity?

Thanks,

ghorrocks · July 19, 2010, 18:40

Velocity magnitude is available by default in CFD-Post. Looks like in tecplot you don't get it. You will have to define velocity magnitude as an equation, as a function of U, V and W. Then it will be a scalar variable that you can do what you like with.

salihovic · July 20, 2010, 03:29

But the problem remains the same.

Mag=sqrt(u²+v²+w²);

then it takes always positive values.

I just want to have Total_Vel=u*i+v*j+w*k, i,j,k---unit vectors

Thanks

ghorrocks · July 20, 2010, 07:11

? Of course Velocity Magnitude is always positive. It is the magnitude of a vector.

I don't know tecplot too well so don't know how they deal with vectors. Generally when you set up a vector field object you define what scalar variable it is to take the X, Y and Z components from. I am sure tecplot will be the same.

TommySean · July 21, 2010, 04:38

I think tecplot should be able to draw contour of velocity magnitude basing on the velocity vector. Are you sure it's uncapable of that?

July 19, 2010, 15:12	Total Velocity	#1
salihovic New Member selim Join Date: Sep 2009 Location: UK Posts: 19 Rep Power: 16	Hi, May be a stupid question? I have U and V velocity, I dont have total velocity (after loading data into tecplot from CFX output--cngs) How can I obtain in tecplot total velocity and make contour of it? In Equation it seems I am allowed to only define scalars? Magnitude I can define, but I want to visualise also some flow reversal, total velocity? Thanks,

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July 19, 2010, 18:40		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	Velocity magnitude is available by default in CFD-Post. Looks like in tecplot you don't get it. You will have to define velocity magnitude as an equation, as a function of U, V and W. Then it will be a scalar variable that you can do what you like with.

July 20, 2010, 03:29		#3
salihovic New Member selim Join Date: Sep 2009 Location: UK Posts: 19 Rep Power: 16	But the problem remains the same. Mag=sqrt(u²+v²+w²); then it takes always positive values. I just want to have Total_Vel=ui+vj+w*k, i,j,k---unit vectors Thanks

July 20, 2010, 07:11		#4
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	? Of course Velocity Magnitude is always positive. It is the magnitude of a vector. I don't know tecplot too well so don't know how they deal with vectors. Generally when you set up a vector field object you define what scalar variable it is to take the X, Y and Z components from. I am sure tecplot will be the same.

July 21, 2010, 04:38		#5
TommySean New Member Tommy Join Date: Jul 2010 Posts: 10 Rep Power: 15	I think tecplot should be able to draw contour of velocity magnitude basing on the velocity vector. Are you sure it's uncapable of that?