Hi there,
I’m new to using the software and currently trying to determine the drag coefficient of a model rocket. Currently, I am getting a drag coefficient that varies massively with time, and is either huge and negative (not theoretically possible with this model) or huge and positive, when a drag coefficient of less than 1 is expected. Some advice of how to set up the model, boundary conditions and other settings would be greatly appreciated. Thanks in advance! https://www.simscale.com/workbench/?pid=3474752018311565922&mi=spec%3Aa913a488-ca1e-4246-aedb-71ecaf1aacbd%2Cservice%3ASIMULATION%2Cstrategy%3A9
I think I have now managed to solve my initial issue. I am trying to simulate the same rocket multiple times, but with nosecones of varying fineness ratio. The software seems to suggest that the drag coefficient is increasing with the fineness ratio, when the opposite is expected. Does anyone have any suggestions as to what is going on here?
Hi @17hille,
Thanks for posting your question!
As we have talked via chat, for the first issue what matters is the final cd value once you’re running a steady-state analysis, so no worries about the initial fluctuations, they are due to iterations.
About the second issue, I still do not see any variation in the nose cones… Could you please show me those variations that you have mentioned above?
best,