Vehicle thermal control with a variable area inlet

This study developed a variable area inlet and controller that regulated the temperature of an electrical component with ram air. The intent of the variable area inlet was to reduce vehicle drag by eliminating inefficiencies associated with component cooling and fixed area inlets. These inefficiencies arise from vehicles moving at varying speeds through varying air temperatures. The system was successful in regulating the component temperature. A nonlinear simulation model was built in MATLAB/sup TM/ SIMULINK/sup TM/ and the thermal plant in the simulation was based on the electrical component's convective heat transfer coefficient, empirically derived in terms of the Nusselt number. Proportional, proportional-derivative (PD), and proportional-integral-derivative (PID) controllers were designed, built, and tested.