### How to calculate the facet normal for a triangle element

Posted:

**Wed Mar 06, 2019 2:04 pm**Hello,

Right now I have a data format file (below) where each row corresponds to a node, and each column corresponds to a variable.

Thus, for every three lines, the values for the variables are repeated, since each node of a triangle is assumed to have the same value.

I believe this is the triangle data in point format. I would like to output a file that has the normal vector for each node.

variables = x y z flux

zone T="sampling", n= 2430 , e= 810 , et=triangle,f=fepoint

0.243636995E-03 0.250523420E-03 0.292066356E-04 0.570100000E+04

0.244069267E-03 0.248489737E-03 0.292066353E-04 0.570100000E+04

0.243637000E-03 0.250523420E-03 0.392066356E-04 0.570100000E+04

I would like to output a file that has the facet normal (nx,ny,nz) at each node:

variables = x y z flux nx ny nz

zone T="sampling", n= 2430 , e= 810 , et=triangle,f=fepoint

0.243636995E-03 0.250523420E-03 0.292066356E-04 0.570100000E+04 nx ny nz

Is there a way for me to calculate the normal vector for each triangle?

I did see an option under "Analyze", "Calculate Variables", and came across "Grid I Unit Normal"

but was not sure this was correct?

I appreciate any advice. My version of Tecplot:Tecplot 360 EX 2018 R2, Version 2018.2.0.92317 (Oct 16 2018)

Thanks for your time,

dreamchaser

Right now I have a data format file (below) where each row corresponds to a node, and each column corresponds to a variable.

Thus, for every three lines, the values for the variables are repeated, since each node of a triangle is assumed to have the same value.

I believe this is the triangle data in point format. I would like to output a file that has the normal vector for each node.

variables = x y z flux

zone T="sampling", n= 2430 , e= 810 , et=triangle,f=fepoint

0.243636995E-03 0.250523420E-03 0.292066356E-04 0.570100000E+04

0.244069267E-03 0.248489737E-03 0.292066353E-04 0.570100000E+04

0.243637000E-03 0.250523420E-03 0.392066356E-04 0.570100000E+04

I would like to output a file that has the facet normal (nx,ny,nz) at each node:

variables = x y z flux nx ny nz

zone T="sampling", n= 2430 , e= 810 , et=triangle,f=fepoint

0.243636995E-03 0.250523420E-03 0.292066356E-04 0.570100000E+04 nx ny nz

Is there a way for me to calculate the normal vector for each triangle?

I did see an option under "Analyze", "Calculate Variables", and came across "Grid I Unit Normal"

but was not sure this was correct?

I appreciate any advice. My version of Tecplot:Tecplot 360 EX 2018 R2, Version 2018.2.0.92317 (Oct 16 2018)

Thanks for your time,

dreamchaser