High-power electrical resistors convert a large part of the supplied electrical energy into heat. Reliable operation therefore depends on keeping component temperatures within acceptable limits and distributing the cooling air effectively.
FlowMotion used CFD to analyse the airflow and heat transfer around a bank of power resistors. The model included the relevant heat generation, cooling-air supply and geometric details that influenced the local flow.
The calculations provided the local velocity and temperature fields and showed where hot spots developed. Because the cooling performance depends on the local air velocity around each resistor, a sufficient total volumetric flow does not automatically guarantee acceptable temperatures everywhere.
Different arrangements and cooling concepts were evaluated numerically. The influence of component spacing, flow direction and ventilation openings on pressure loss and temperature distribution could therefore be assessed before hardware changes were made.
The CFD analysis provided a targeted route to reducing peak temperatures and improving the thermal reliability of the system.
