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sandialabs / CACTUS

CACTUS (Code for Axial and Cross-flow TUrbine Simulation) is a turbine performance simulation code, based on a free wake vortex method, to study wind turbines and marine hydrokinetic (MHK) devices.
BSD 3-Clause "New" or "Revised" License
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Blade Reynolds number was above table limit #33

Open danrhouck opened 4 years ago

danrhouck commented 4 years ago

I've gotten this warning at the end of simulations a few times: AT LEAST ONE BLADE REYNOLDS NUMBER WAS ABOVE TABLE LIMIT. UPPER LIMIT USED. I'm surprised to see it, though. In deciding what Reynolds numbers to use to calculate polars, I calculated all possible Reynolds numbers using the chord distribution and tip speed ratio to get the relative velocities, and then the freestream velocity to get the resultant at each span location. The highest Reynolds number that I used for my polars is about twice the highest Reynolds number I calculated. Could you verify how the Reynolds number is being determined in the simulation and, perhaps, explain how it could be so much higher than my estimates?

whophil commented 4 years ago

Do your airfoil tables contain data for multiple Reynolds numbers, or just one? It looks like this error will be written if there is only one Reynolds number for any given airfoil.

https://github.com/SNL-WaterPower/CACTUS/blob/1776c78f61aab9366342469c8df07459e2b74ef0/src/mod/airfoil.f95#L94-L98

danrhouck commented 4 years ago

The only foil with only one Reynolds is the circular profile at the root. Perhaps it was just that one. Is there no way to tell which blade section it was?

From: Phil Chiu notifications@github.com Sent: Thursday, August 13, 2020 10:18 PM To: SNL-WaterPower/CACTUS CACTUS@noreply.github.com Cc: Houck, Daniel Russell drhouck@sandia.gov; Author author@noreply.github.com Subject: [EXTERNAL] Re: [SNL-WaterPower/CACTUS] Blade Reynolds number was above table limit (#33)

Do your airfoil tables contain data for multiple Reynolds numbers, or just one? It looks like this error will be written if there is only one Reynolds number for any given airfoil.

https://github.com/SNL-WaterPower/CACTUS/blob/1776c78f61aab9366342469c8df07459e2b74ef0/src/mod/airfoil.f95#L94-L98

— You are receiving this because you authored the thread. Reply to this email directly, view it on GitHubhttps://github.com/SNL-WaterPower/CACTUS/issues/33#issuecomment-673874069, or unsubscribehttps://github.com/notifications/unsubscribe-auth/AP7KH35OHIZIX4RILGWGBN3SAS3IVANCNFSM4PE4UPPA.

whophil commented 4 years ago

Not as written, it appears the error flag which controls the printing of that message, IUXTP, is global. It should be easy to modify to make it do what you want.