Development of a Rapid Vehicle Steering Cooling System Using Thermoelectrics

Nowadays automotive cabin comfort has become a necessity rather than an optional feature, with customers demanding more comfort features. Thermal comfort becomes an essential part of this expectation. Since steering wheel is the first surface that the driver will touch once he enters the vehicle, maintaining thermal comfort of steering wheel becomes important, especially in tropical countries like India where a car parked in hot weather can get significantly warm inside. In this work, two design concepts for automotive steering wheel thermal control based on thermoelectric effect are depicted along with a detailed mathematical model. Thermoelectric coolers were selected for this purpose as it is solid state, compact & scalable solution to achieve rapid cooling rates. This was the desired feature expected from an integration standpoint in automotive architecture. Since there was an absence of 1D model for thermoelectric coolers (TEC) in open literatures, it was built using the mathematical model. Two basic concepts of cooling the steering were used viz. conductive and indirect convective. The indirect convective cooling involved using Phase Changing Material (PCM) to absorb heat dissipated by the TEC at constant temperature. This latent heat was absorbed at almost constant temperature and then dissipated to atmosphere via convection. Two of the design concepts were modelled in 1D environment. The entirety of the model was built in 1D simulation platform KULI, which is specifically used for thermal management. The models were then simulated at different operating points and initial conditions to see how the average surface temperature of the steering wheel would change in transient condition. The target of the study was to achieve steering surface temperatures of 30°C- 34°C in 15-20 seconds. A test was conducted after prototype build to validate the simulation model and was found in close agreement with the simulated results.