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Subsonic and Transonic Flow

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Old   March 3, 2018, 09:20
Default Subsonic and Transonic Flow
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Daniel
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Hello there,

I am simulating a 4-stage axial compressor with subsonic flow.
When I evaluated the mach-number at the inlet of the first rotor row, the Mach-number near the Shroud reached 0.85.
For me this is a little but curious since I defined the flow with subsonic.
Is it normal, that the Flow exceeds 0.8 for transonic flow conditions?

Thank you very much!
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Old   March 3, 2018, 10:49
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yes very much normal
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Old   March 3, 2018, 12:58
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Thanks for the answer

But is there any explanation for this ?
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Old   March 3, 2018, 13:01
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isnt is the velocity triangle. at tip the blade speed is higher, so the mach number
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Old   March 3, 2018, 13:02
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you have to check it is relative mach number or mach number.
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Old   March 3, 2018, 13:04
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I only can choose Mach Number and Mach Number in Stn Frame.
And for the Rotor I've chosen the regular Mach Number.
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Old   March 3, 2018, 13:55
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it is relative mach number
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