This section is going to explain how to use SimScale to run for computational fluid dynamics (CFD) simulations of a solar car. It will cover the basics of a simple, steady-state case and discuss some of the more advanced settings, but will assume some knowledge of fluids. This information has been compiled from what I was taught by more experienced members, my own research, and my experiences while simulating MSXIV.
If you want to read about CFD simulations in ANSYS Fluent, there’s this page from the development of MSXII. That page is a great resource in general as it also discusses the workflow of CFD simulations and explains settings concisely.
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As of the time of writing, our results have not been validated. I will update this section when we have physical data and measurements from MSXIV but until then keep this in mind. |
What is SimScale?
SimScale is a web-based simulation platform, which allows the user to simulate how their CADed design would behave instead of having to build a prototype of their design and test it. What sets SimScale apart from the other simulation programs (like ANSYS) is that SimScale takes advantage of cloud computing. CFD simulations are usually very computationally demanding, which can take days to run on an average computer. Cloud computing means users can send their simulations to SimScale, who use really powerful computers to finish moderately large simulations in a couple of hours, and send the results back. There are also several other benefits to using SimScale, such as having a simple and intuitive user interface, access to help from simulation experts, and educational tools to learn about simulation theory.
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In the top bar, there is a drop-down menu for Learning. Go here for tutorials, webinars, and documentation. In the top right, you can log in or sign up for a new account. Free accounts (also called community accounts) are limited to 16 computing cores and 3,000 core hours. This account type is great for personal accounts where you can learn how to use SimScale and test things out.
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The team was sponsored during the design of MSXIV, which granted us a the team an account with a 32 core limit, over 40,000 core hours, and private projects. That may seem like an excessive number of core hours, especially when compared to a community account, however CFD simulations can easily consume that many hours. It is recommended that In the future, I would recommend planning core hour use is planned out and that reserving a portion of the team account’s core hours are reserved for advanced simulations (Cross winds, rotating wheels, ventilation, etc) if these results are desired. Tips for reducing core hour use will be discussed throughout.
I’ll divide the simulation workflow into 4 subsections, each one must be completed before moving on to the next one:
Setting up the project (and importing geometry)