Pressure Fluctuations Using cyclicAMI Boundary ：v9 vs v2206

Gavin Tall · September 21, 2022, 03:47

Differences in the calculation results of the versions：
The calculation results of the v9 version are normal，But the v2206 version has jumping fluctuations in pressure (with the same case parameter settings);

Gavin Tall · September 21, 2022, 04:37

A horizontally placed circular tube with one inlet and one outlet; use the cyclic boundary "cyclicAMI" for inlet and outlet；

Change the boundary condition to "fiaedvalue", the calculation of side v2206 is normal; it is also normal to use v9 for calculation without modification;

But running the cyclic boundary of "cyclicAMI" with v2206, there are fluctuations in pressure

Gavin Tall · September 21, 2022, 04:44

The above attachment is the v2206 version of the case, modified from v9, there is no problem with the operation, and the resulting pressure fluctuation is shown in the figure：

Gavin Tall · September 21, 2022, 21:57

Maybe it's the choice of discrete format. I tried different divSchemes and got slightly better results, but the pressure still fluctuates.
It stands to reason that the pressure should be almost stable at 1e5 ，and shouldn't jump from 1.1e5 to 1.3e5 to 1.2e5 again...;confused...

September 21, 2022, 03:47	Pressure Fluctuations Using cyclicAMI Boundary ：v9 vs v2206	#1
Gavin Tall New Member 无 Join Date: Jul 2022 Posts: 8 Rep Power: 3	Differences in the calculation results of the versions： The calculation results of the v9 version are normal，But the v2206 version has jumping fluctuations in pressure (with the same case parameter settings);

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September 21, 2022, 21:57		#4
Gavin Tall New Member 无 Join Date: Jul 2022 Posts: 8 Rep Power: 3	Maybe it's the choice of discrete format. I tried different divSchemes and got slightly better results, but the pressure still fluctuates. It stands to reason that the pressure should be almost stable at 1e5 ，and shouldn't jump from 1.1e5 to 1.3e5 to 1.2e5 again...;confused...