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RMS is missing?

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Old   March 22, 2019, 19:44
Question RMS is missing?
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Oguzhan
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Hi,

I remember there used to be RMS option for unsteady statistics in FLUENT but I dont seem to find RMS, there is just RMSE. When I check the user/theory guide, it does still mention both RMS and RMSE.

Does anyone know why RMS is not available?

Thanks.
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Old   March 23, 2019, 01:19
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Lucky
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RMS has been corrected to RMSE. There's never been an RMS option, that was a typo and a bug. Before it said RMS but was actually calculating the RMSE. It has always calculated the RMSE and the interface has been updated to reflect that.

Well, it wasn't a bug per se. But a lot of people (like you) get it confused. It was presumed obvious that it is was the rms of the velocity fluctuations which is the rmse of the full velocity.
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Old   March 23, 2019, 16:19
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Quote:
Originally Posted by LuckyTran View Post
RMS has been corrected to RMSE. There's never been an RMS option, that was a typo and a bug. Before it said RMS but was actually calculating the RMSE. It has always calculated the RMSE and the interface has been updated to reflect that.

Well, it wasn't a bug per se. But a lot of people (like you) get it confused. It was presumed obvious that it is was the rms of the velocity fluctuations which is the rmse of the full velocity.
Thanks for the answer. Let me ask you one more question, just to make sure its all clear. If I want to calculate RMS of velocity fluctuation u' , I should use RMSE of instantaneous velocity u_ins. Right?

Thanks.

Last edited by heisenmech; March 24, 2019 at 07:54.
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Old   March 25, 2019, 08:56
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Right. rms of velocity fluctuation u' (which has 0 mean) is the same as the rmse of the instantaneous velocity u(t), which does not have 0 mean.
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flow statistics, rms, rmse, unsteady flow, unsteady statistics

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