A Sensitivity Study of Occupant Thermal Comfort in a Cabin Using Virtual Thermal Comfort Engineering

Simulation of cabin climatic conditions is becoming increasingly important as a complement to wind tunnel and field testing to help achieve improved thermal comfort while reducing vehicle development time and cost. Delphi developed the Virtual Thermal Comfort Engineering (VTCE) process to explore different climate control strategies as they relate to occupant thermal comfort in a quick and inexpensive manner. The comfort model has the ability to predict the local thermal comfort level of an occupant in a highly non-uniform thermal environment as a function of air temperature, surrounding surface temperatures, air velocity, humidity, direct solar flux, as well as the level of activity and clothing type of each individual. In the present study, we used test data to validate VTCE for a Sport Utility Vehicle (SUV) cabin environment and used VTCE to perform sensitivity studies of various vehicle cabin environments on the occupant thermal comfort, including discharge temperature, breath level temperature and air velocity, solar intensity and solar angles. The sensitivity of the occupant thermal comfort, in the present study, is based on an OEM's comfort scale for both summer and the winter rides.