Prediction of Charge Air Cooler Performance in a Racing Drive Cycle by 1D-3D Coupling 2018-01-0781
Charge air temperature needs to be kept low for optimum engine operation. If charge air temperature is too high, engine performance reduction strategies are invoked to protect engines by limiting torque available to drivers. A 1D-3D coupling simulation methodology is developed to accurately predict internal air temperature after charge air cooler (CAC) during a racing drive cycle. The 3D flow simulation is used to characterize external air flow before CAC in steady-state cases. Then, interpolated 3D simulation results between steady operating points are used as transient external air boundary conditions in front of CAC in a 1D system model. 3D flow simulation is also used to predict internal flow rate ratio between CAC tubes. Finally, an 1D system model is used to predict time-trace of charge air temperature at CAC internal outlet during the racing drive cycle. The simulation results show that prediction errors are within 5 degrees for charge air temperature at internal outlets. This methodology helps inform styling, component sizing & package decisions during the vehicle concept phase and avoiding costly hardware changes post tooling kick off. The approach leads to optimized CAC temperatures during all driving conditions yielding full engine torque and increased engine durability.