Problem in exporting data

Safasml · May 30, 2020, 10:10

Hi all,
I am trying to export the pressure data on a blade at specific points (100 points). So I create a polyline in cfx-post, which read the points from a file and export the pressure on that polyline. But the problem is that the pressure is written on just 99 points, not all the 100 points. All of the points are on the blade surface.
What is the problem and how can I solve it?

ghorrocks · May 31, 2020, 06:46

Use a point cloud, not a polyline to define your points.

Safasml · May 31, 2020, 07:13

Dear Glenn,
I’d tried to use point cloud instead of a polyline, but as I understood, the point cloud determines the points by itself. I mean that I want the pressure to be written at specific points with specific x, y and z. but the point cloud determines the points, for example, randomly or in equal space or other ways. So, I decided to use a polyline in which I could determine the points by myself.

ghorrocks · May 31, 2020, 18:54

Have you looked at the point cloud option? There is a method: "From file" option, which appears to be where you import a CSV file with all the locations for the point. This appears to do exactly what you want.

Safasml · June 1, 2020, 00:22

Dear Glenn,
Of course I checked the options, but I cannot find “from file” option. Can you help me where is it? I attached the details window of the point cloud. That’s all I can see.

ghorrocks · June 1, 2020, 00:28

You must be using an old version of CFX as the option does not appear to be there. About time to update I think.

Safasml · June 1, 2020, 01:04

I’m using ANSYS 2019 R1… anyway… it’s not possible for me to update it now.

icem_god · June 1, 2020, 07:48

try User Surface -> From File

Sumanth_094 · June 16, 2020, 09:05

I encountered something similar recently. Even when you create a point cloud in CFD Post and you give in 100 as number of points, only 99 will be created.
I simply would give in 1 value extra to make up for this.

Have no clue how and why the software does this.

I usually take out data from a large number of points along the surface or line needed and then interpolate them onto the points I need later in Matlab. Ofc, this brings in an interpolation error but if you have enough number of data points, this error could be something which you can ignore.

Hope this helps!

Opaque · June 16, 2020, 09:43

May I ask how you know there are 99 and not 100?

Are you looking at the column with the node number? or counted the lines one by one?

CFD-Post numbers the rows in the .csv file starting at 0, even if you do not include the row number. Perhaps that is the problem?

Sumanth_094 · June 18, 2020, 04:20

I stand corrected. Opaque was right

May 30, 2020, 10:10	Problem in exporting data	#1
Safasml Member Join Date: Oct 2017 Posts: 35 Rep Power: 8	Hi all, I am trying to export the pressure data on a blade at specific points (100 points). So I create a polyline in cfx-post, which read the points from a file and export the pressure on that polyline. But the problem is that the pressure is written on just 99 points, not all the 100 points. All of the points are on the blade surface. What is the problem and how can I solve it?

May 31, 2020, 06:46		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	Use a point cloud, not a polyline to define your points. __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

May 31, 2020, 18:54		#4
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	Have you looked at the point cloud option? There is a method: "From file" option, which appears to be where you import a CSV file with all the locations for the point. This appears to do exactly what you want. __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

June 1, 2020, 00:28		#6
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	You must be using an old version of CFX as the option does not appear to be there. About time to update I think. __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

June 16, 2020, 09:43		#10
Opaque Senior Member Join Date: Jun 2009 Posts: 1,804 Rep Power: 32	May I ask how you know there are 99 and not 100? Are you looking at the column with the node number? or counted the lines one by one? CFD-Post numbers the rows in the .csv file starting at 0, even if you do not include the row number. Perhaps that is the problem? __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

May 31, 2020, 07:13		#3
Safasml Member Join Date: Oct 2017 Posts: 35 Rep Power: 8	Dear Glenn, I’d tried to use point cloud instead of a polyline, but as I understood, the point cloud determines the points by itself. I mean that I want the pressure to be written at specific points with specific x, y and z. but the point cloud determines the points, for example, randomly or in equal space or other ways. So, I decided to use a polyline in which I could determine the points by myself.

June 1, 2020, 01:04		#7
Safasml Member Join Date: Oct 2017 Posts: 35 Rep Power: 8	I’m using ANSYS 2019 R1… anyway… it’s not possible for me to update it now.

June 1, 2020, 07:48		#8
icem_god New Member Join Date: Nov 2017 Posts: 22 Rep Power: 8	try User Surface -> From File

June 16, 2020, 09:05		#9
Sumanth_094 New Member Sumanth Join Date: Aug 2018 Location: Germany Posts: 21 Rep Power: 7	I encountered something similar recently. Even when you create a point cloud in CFD Post and you give in 100 as number of points, only 99 will be created. I simply would give in 1 value extra to make up for this. Have no clue how and why the software does this. I usually take out data from a large number of points along the surface or line needed and then interpolate them onto the points I need later in Matlab. Ofc, this brings in an interpolation error but if you have enough number of data points, this error could be something which you can ignore. Hope this helps!

June 18, 2020, 04:20		#11
Sumanth_094 New Member Sumanth Join Date: Aug 2018 Location: Germany Posts: 21 Rep Power: 7	I stand corrected. Opaque was right

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