Why Custom Codes

[ysm]

I am not into CFD but just curious. Why do some companies use custom codes? What is it that the commercial softwares don't provide. When they say custom codes are these only subroutines to commercial codes or the entire pre, post processors along with the engine are written from scratch?

Thanks
YSM

 

[phands]

It is basically an issue of the questions that are needed to be answered that drive the use. Researchers usually write their own CFD code because they are interested in a certain area. These in-house codes are usually written in a specific descritization scheme to increase accuracy or speed. With an increase in computing power, things like LES simulations are now possible to give high resolution answers, which before were not possible. Thusly, researchers generally don't use RANS models anymore.

 

[btrueblood]

"Why do some companies use custom codes?"

Many companies developed in-house codes, or borrowed codes and modified them from open sources, many years before commercieal CFD codes were around. A lot of work and time, and quality control (benchmarking to test data) of the legacy codes has been done, and similar efforts would be required to transfer to a commercial code.