Output file's Inlet Speed differs from my input

Blooper · July 20, 2014, 14:33

What could cause this problem? I've set the inlet mach to 0.06408 (which leads to a dimensional speed of 22.2815 m/s), and when I start running it the DOS messages even state the correct datas on the initialization messages, but after it finishes processing, the surface_flow file shows the inlet mach averaging about 0.025.

Could this result from an imposed pressure gradient which forces the inlet speed to change? Or is it something else entirely?

Thanks in advance for any info and tips.

P.S.: This is an internal flow on a tubular channel.

Blooper · July 20, 2014, 14:50

Well, apparently the problem was a mistakenly imposed pressure gradient. I was using the standard inlet type with temperature and pressure (and imposed a pressure gradient by mistake), but when I changed to the MASS_FLOW inlet type, the calculations matched the expectations.

Sorry for the hassle.

July 20, 2014, 14:33	Output file's Inlet Speed differs from my input	#1
Blooper New Member Brazil Join Date: May 2014 Posts: 8 Rep Power: 12	What could cause this problem? I've set the inlet mach to 0.06408 (which leads to a dimensional speed of 22.2815 m/s), and when I start running it the DOS messages even state the correct datas on the initialization messages, but after it finishes processing, the surface_flow file shows the inlet mach averaging about 0.025. Could this result from an imposed pressure gradient which forces the inlet speed to change? Or is it something else entirely? Thanks in advance for any info and tips. P.S.: This is an internal flow on a tubular channel.

July 20, 2014, 14:50		#2
Blooper New Member Brazil Join Date: May 2014 Posts: 8 Rep Power: 12	Well, apparently the problem was a mistakenly imposed pressure gradient. I was using the standard inlet type with temperature and pressure (and imposed a pressure gradient by mistake), but when I changed to the MASS_FLOW inlet type, the calculations matched the expectations. Sorry for the hassle. Last edited by Blooper; July 20, 2014 at 14:51. Reason: typo

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