Abstract:

Low pressure die casting (LPDC) is the preferred method to manufacture cost-effective automotive wheels. Cooling systems and channels of a low pressure die casting are critical to obtain better mechanical properties. Both steady-state and time-dependent (transient) Computational Fluid Dynamics (CFD) analyses of the cooling channels and the die cooling system, both in conjugate and solid-only models, are performed and the pipe flow part of the results are compared with the available experimental data. Pipes operate at a schedule transiently, therefore a complex time-dependent simulation is required. The aim is to construct a simplified approach in which only the solids (die and cast wheel) are considered and pipe cooling is represented by heat transfer coefficient distribution obtained from the much faster steady-state simulations. Successful results are obtained by significantly reducing the computational time while retaining the same accuracy. Finally, cooling channels with eight different diameter stream-wise distributions are analyzed to explore their impact on pipe exit velocity and mass flow rate as a guidance towards future works. Wheels are cast with the simulated cooling system and are approved by mechanical tests.

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