Please help newbie simulation

Stephen_s_2510 · November 28, 2013, 13:17

I'm trying to simulate a pump in CFD but I'm quite a novice, i'm following a tutorial for a similar pump which I was able to simulate but for my own pump i'm really struggling. I can't really get hold of my teacher so i turned to here.

I'll start with a picture of the Geometry
http://oi39.tinypic.com/2czx4ao.jpg
I defined regions- the tube at the right is the inlet, therefore i changed the face of the inlet to a mass inlet
The face on the left is a pressure outlet.

I meshed it with a Surface Re-mesher & Polyhedral Mesher with a base size of 0.005
I applied these Physics Conditions:
http://oi42.tinypic.com/szjuqu.jpg
I specified the turbulent specification to be a length + intensity scale with the intensity of 0.05.
I set up a rotation motion under tools, In the positive Z direction and at 125 rads. I then applied this motion to the main body ( central body ) and changed it so the absolute rotation of the outer surface was 0.
I added rotation to the rotor in the inlet as well.

I changed the Implicitly Unsteady time step to 0.0020 s, Maximum inner iterations to 100, and maximum physical time to 0.5s

I set up 2 reports, a mass input(related to mass inlet face) and mass out (From discharge face)

I set up a vector scene and ran the simulation, and i didn't really get very good results.

Vector Scene http://oi39.tinypic.com/28gxa43.jpg
Notice the hub at the end of the main body has rotated

From
http://oi41.tinypic.com/2ic7hci.jpg to http://oi41.tinypic.com/2zjmfia.jpg
Also my reports are blank, no mass flow in or out

And my energy equation doesn't converge

http://oi42.tinypic.com/2lv0cxf.jpg

The rotation doesn't look correct either, so not sure !

Please can somebody give me some pointers !

ggulgulia · December 4, 2013, 06:48

Hey Stephen

Can you upload a video or a detailed description of how the video pump should worK?

And how did you arrive at the number of inner iterations? I feel it's very high.

How is the mesh? Can you upload some sectional views of the critical regions of mesh?

ggulgulia · December 4, 2013, 06:55

for your reports, did you assign the boundary where the report should calculate the value?

[/IMG]

November 28, 2013, 13:17	Please help newbie simulation	#1
Stephen_s_2510 New Member steve Join Date: Nov 2013 Posts: 1 Rep Power: 0	I'm trying to simulate a pump in CFD but I'm quite a novice, i'm following a tutorial for a similar pump which I was able to simulate but for my own pump i'm really struggling. I can't really get hold of my teacher so i turned to here. I'll start with a picture of the Geometry http://oi39.tinypic.com/2czx4ao.jpg I defined regions- the tube at the right is the inlet, therefore i changed the face of the inlet to a mass inlet The face on the left is a pressure outlet. I meshed it with a Surface Re-mesher & Polyhedral Mesher with a base size of 0.005 I applied these Physics Conditions: http://oi42.tinypic.com/szjuqu.jpg I specified the turbulent specification to be a length + intensity scale with the intensity of 0.05. I set up a rotation motion under tools, In the positive Z direction and at 125 rads. I then applied this motion to the main body ( central body ) and changed it so the absolute rotation of the outer surface was 0. I added rotation to the rotor in the inlet as well. I changed the Implicitly Unsteady time step to 0.0020 s, Maximum inner iterations to 100, and maximum physical time to 0.5s I set up 2 reports, a mass input(related to mass inlet face) and mass out (From discharge face) I set up a vector scene and ran the simulation, and i didn't really get very good results. Vector Scene http://oi39.tinypic.com/28gxa43.jpg Notice the hub at the end of the main body has rotated From http://oi41.tinypic.com/2ic7hci.jpg to http://oi41.tinypic.com/2zjmfia.jpg Also my reports are blank, no mass flow in or out And my energy equation doesn't converge http://oi42.tinypic.com/2lv0cxf.jpg The rotation doesn't look correct either, so not sure ! Please can somebody give me some pointers !

December 4, 2013, 06:48		#2
ggulgulia Senior Member Gajendra Gulgulia Join Date: Apr 2013 Location: Munich Posts: 144 Rep Power: 13	Hey Stephen Can you upload a video or a detailed description of how the video pump should worK? And how did you arrive at the number of inner iterations? I feel it's very high. How is the mesh? Can you upload some sectional views of the critical regions of mesh? Last edited by ggulgulia; December 4, 2013 at 06:56. Reason: grammatical mistake

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December 4, 2013, 06:55		#3
ggulgulia Senior Member Gajendra Gulgulia Join Date: Apr 2013 Location: Munich Posts: 144 Rep Power: 13	for your reports, did you assign the boundary where the report should calculate the value? [/IMG]