Blank white space in flow analysis?

Welshnathan · March 11, 2011, 13:46

Hello everyone,

My name is Nathan and I'm new here and to CFD in general so I apologise in advance if I'm not making sense. Anyway, I'm hoping someone can shed some light on an issue I'm having with my analysis.

I am currently in my third year at university and my thesis entails designing a blended wing body aircraft and running an aerodynamic analysis of the plane in Phoenics in order to obtain drag, lift and moment coefficients.
My model has been created using SolidWorks and saved in the .STL file format with varying degrees of mesh quality.
My problem is after running the analysis, everything looks fine at first but on closer inspection, there are one or two large blank spaces when I plot the pressure or velocity, the flow that is plotted is actually not of the model but the small blank spaces. Has anyone else had this problem?
I can only assume that this is due to some complex geometry in the model when SolidWorks converts to STL. I have tried using Netfabb studio to repair the files but then Phoenics crashes if I try to import that new STL file.

I have attached a photo (removed 17/03/11), it might explain it a lot better than I can!
I hope I’ve made enough sense for someone to help. Any recommendations on an STL repair program if that’s the issue?

Thanks everyone!

Welshnathan · March 17, 2011, 14:10

Its fine now, my grid mesh was too course for the model.

On another note, is there some piece of software that displays better post-analysis results? Phoenics is pretty limited.
Better-still, can results from Phoenics be exported to Ansys 12?

March 11, 2011, 13:46	Blank white space in flow analysis?	#1
Welshnathan New Member Nathan Join Date: Mar 2011 Posts: 6 Rep Power: 15	Hello everyone, My name is Nathan and I'm new here and to CFD in general so I apologise in advance if I'm not making sense. Anyway, I'm hoping someone can shed some light on an issue I'm having with my analysis. I am currently in my third year at university and my thesis entails designing a blended wing body aircraft and running an aerodynamic analysis of the plane in Phoenics in order to obtain drag, lift and moment coefficients. My model has been created using SolidWorks and saved in the .STL file format with varying degrees of mesh quality. My problem is after running the analysis, everything looks fine at first but on closer inspection, there are one or two large blank spaces when I plot the pressure or velocity, the flow that is plotted is actually not of the model but the small blank spaces. Has anyone else had this problem? I can only assume that this is due to some complex geometry in the model when SolidWorks converts to STL. I have tried using Netfabb studio to repair the files but then Phoenics crashes if I try to import that new STL file. I have attached a photo (removed 17/03/11), it might explain it a lot better than I can! I hope I’ve made enough sense for someone to help. Any recommendations on an STL repair program if that’s the issue? Thanks everyone! Last edited by Welshnathan; March 17, 2011 at 14:12.

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March 17, 2011, 14:10		#2
Welshnathan New Member Nathan Join Date: Mar 2011 Posts: 6 Rep Power: 15	Its fine now, my grid mesh was too course for the model. On another note, is there some piece of software that displays better post-analysis results? Phoenics is pretty limited. Better-still, can results from Phoenics be exported to Ansys 12?