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Computational Fluid Dynamics simulation of aero-acoustics requires a high fidelity mesh. For Direct simulations, a very good quality and reasonably refined mesh is required in the entire domain encompassing the source and receiver of the sound. A usual practice so far has been to use structured grid to mesh the geometries. For complex geometrical shapes, such as throttle body, creating a fully structured mesh becomes very tedious and could consume a lot of time. Once the computational model is in place, obtaining meaningful solution also takes a long time since the solution has to be run for quite the long time in order to capture reasonably accurate sound pressure data. The current paper focuses on both of these time-consuming aspects. A comparative study of three different mesh types in a throttle body geometry is considered.

CFD simulations of an engine cooling system needs to resolve two aspects of the system; in-cylinder combustion and engine cooling. Underlying physics of an in-cylinder combustion process and heat transfer through engine cooling system requires very different time scales for resolution. This puts a limitation on practicality of solving the two problems simultaneously for any industrial case. Instead of solving the problem simultaneously, solution for an engine cooling system operating at a constant load can be derived using the coupled approach. This involves running two different CFD simulations: a transient in-cylinder simulation to model combustion in the engine, and a steady state CHT simulation using engine cooling system for heat transfer. These simulations are thermally coupled through boundary conditions and are performed in cyclic manner one after the other. Simulations are continued till the change in temperature with coupled cycles becomes insignificant.