supersonic flow inside orifice

KartoffelFlow · October 30, 2022, 05:48

Hi Everyone,

I am working on the simulation of flows through small orifices. For this purpose I am using Ansys Forte 2021 R2 and I reproduce the work of Kayser and Shambaugh (1991, https://www.researchgate.net/publica...ergent_nozzles).

My simulations of orifice S1 at high pressures result in a Mach numbers > 1 inside the orifices (with sonic booms and shock diamonds, https://imgur.com/a/R04tqNB). I was able to reproduce the same in Ansys Fluent. If the length of the bore is extended, this effect does not occur. My guess is that the strong contraction and expansion (from 15.18 mm diameter to 1.125 mm diameter to the environment) beeing so near to each other creates a laval nozzle.

Unfortunately, I could not find any literature on this, do you know where I can find something?

LJA_Koers · July 4, 2023, 06:07

I'm running into the same problem. Have you found a solution?

October 30, 2022, 05:48	supersonic flow inside orifice	#1
KartoffelFlow New Member Join Date: Oct 2022 Posts: 1 Rep Power: 0	Hi Everyone, I am working on the simulation of flows through small orifices. For this purpose I am using Ansys Forte 2021 R2 and I reproduce the work of Kayser and Shambaugh (1991, https://www.researchgate.net/publica...ergent_nozzles). My simulations of orifice S1 at high pressures result in a Mach numbers > 1 inside the orifices (with sonic booms and shock diamonds, https://imgur.com/a/R04tqNB). I was able to reproduce the same in Ansys Fluent. If the length of the bore is extended, this effect does not occur. My guess is that the strong contraction and expansion (from 15.18 mm diameter to 1.125 mm diameter to the environment) beeing so near to each other creates a laval nozzle. Unfortunately, I could not find any literature on this, do you know where I can find something?

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July 4, 2023, 06:07		#2
LJA_Koers New Member Laurens Join Date: Sep 2018 Location: the Netherlands Posts: 20 Rep Power: 8	I'm running into the same problem. Have you found a solution?