Flow Separation in GE frame 9 Compressor CFD simulation

chocolater · October 23, 2017, 15:54

Has anybody simulated GE frame 9 Compressor? I had simulated this 17th stages compressor with the CFX; when I used a coarse mesh with y+=30 and k-w turbulence model, there is no problem in convergence and everything in CFD-POST is fine. But when it comes to simulating with a fine mesh, y+=1 and SST turbulence model; Inlet mass decreases and post-process show a big region of flow separation near the leading edge close to the hub. Can anybody give me any tips?

CFDpal · October 27, 2017, 12:35

Typically, certain flow effects are not captured on coarse mesh. They are smeared over the cell volume. Separation at the hub is a problem. Try to eliminate/isolate the problem and simulate the stage with different boundary conditions (reduce discharge pressure, or mass for example). See if the separation is still present.

Frankly, I do not have experience with that particular frame.

CFDpal

October 23, 2017, 15:54	Flow Separation in GE frame 9 Compressor CFD simulation	#1
chocolater New Member i man Join Date: Feb 2013 Posts: 10 Rep Power: 13	Has anybody simulated GE frame 9 Compressor? I had simulated this 17th stages compressor with the CFX; when I used a coarse mesh with y+=30 and k-w turbulence model, there is no problem in convergence and everything in CFD-POST is fine. But when it comes to simulating with a fine mesh, y+=1 and SST turbulence model; Inlet mass decreases and post-process show a big region of flow separation near the leading edge close to the hub. Can anybody give me any tips?

October 27, 2017, 12:35		#2
CFDpal New Member CFDpal Join Date: Mar 2017 Location: Boston, MA Posts: 20 Blog Entries: 1 Rep Power: 9	Typically, certain flow effects are not captured on coarse mesh. They are smeared over the cell volume. Separation at the hub is a problem. Try to eliminate/isolate the problem and simulate the stage with different boundary conditions (reduce discharge pressure, or mass for example). See if the separation is still present. Frankly, I do not have experience with that particular frame. CFDpal chocolater likes this.

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