The requirements of the automotive industry move along due to product competitiveness and this contributes to increase complexity in the requirements for evaluation. Simulation tools play a key role thanks to their versatility and multiple physical phenomena that can be represented.
The axis of analysis for this paper is the problem of the interaction of airflow and water flow in the cowl/plenum/leaf screen components. Airflow is represented by HVAC system operating and water flow by the vehicle in torrential rain.
Initially, one simulation is evaluated at a time, in one side, the airflow entering the HVAC system in which the amount of air entering is monitored and pressure drop, on the other, the water simulation on the vehicle, both using a Lagrangian CFD model (using with tools such as STAR CCM+® or Ansys Fluent®)
Due to this, a CFD methodology was developed to evaluate the interaction of air and water flow. This uses CFD Eulerian model for airflow and a Lagrangian model for water, in which results from the initial simulation are included to evaluate the interaction of both fluids and consequently obtain a more significant result for water particle behavior.
The research results show a significant change in the amount of water distribution in the system when it has airflow as an initial boundary condition.
Furthermore, the kinematics of the windshield wipers is another key factor in the study, and it changes the physics of this analysis, which is currently under development to provide more effective results.