Cavitation UDF -- VOF of phase 2 is 0

seinfeld2 · August 27, 2018, 01:13

Hello,

I'm trying to hook the Schnerr-Sauer cavitation model via UDF but I'm having an issue. The model requires multiplying by the volume fraction of the second phase but if my entire domain is water, the vol fraction of water vapor is always 0 so the mass transfer never starts. Does anyone know how to solve this issue?

cfdxyz · October 18, 2018, 07:01

I have the same problem. The source term in the default Sauer cavitation model could work even when I set entire domain as pure water. I have no idea how the source term works. However, the Sauer cavitation model written in udf could work when I set a very small value of vapor volume fraction in the initial condition.
In addition, there is a difference that can not be neglected between the default Sauer cavitation and Sauer cavitation model written in udf in pressure distribution.

August 27, 2018, 01:13	Cavitation UDF -- VOF of phase 2 is 0	#1
seinfeld2 New Member Join Date: Jan 2018 Posts: 3 Rep Power: 8	Hello, I'm trying to hook the Schnerr-Sauer cavitation model via UDF but I'm having an issue. The model requires multiplying by the volume fraction of the second phase but if my entire domain is water, the vol fraction of water vapor is always 0 so the mass transfer never starts. Does anyone know how to solve this issue?

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October 18, 2018, 07:01		#2
cfdxyz New Member Join Date: Oct 2018 Posts: 1 Rep Power: 0	I have the same problem. The source term in the default Sauer cavitation model could work even when I set entire domain as pure water. I have no idea how the source term works. However, the Sauer cavitation model written in udf could work when I set a very small value of vapor volume fraction in the initial condition. In addition, there is a difference that can not be neglected between the default Sauer cavitation and Sauer cavitation model written in udf in pressure distribution.