Methodology for optimized automotive grill opening area prediction based on 1D simulation approach and correlation with prototype test Model

This paper discusses the methodology setup for grill opening area prediction at the early development phase of product development lifecycle, using commercially available 1D simulation tool- AMESIM. Representative under hood has been modeled using Grill, Condenser, Radiator, intercooler, fan and engine components. Vehicle velocity is used as an input to derive the airflow passing through the grill and other under-hood components based on ram air coefficient, pressure drop through different components (Grill, Heat exchanger, Fan & Engine). This air flow is used to predict the top tank temperature of radiator. Derived airflow is correlated with air flow obtained from CFD simulation. A balance has been achieved between cooling drag & fan power consumption at different grill opening area for Target Top tank temperature. Top tank temperature has been predicted at two different extreme engine heat rejection operating points. Proposed methodology has shown good correlation with prototype testing on Dyno level test data.