Investigation of Thermal Response of an Automobile Passenger with a Ventilated Seat

Kwangjin Shin, Marquette University


This research presents mathematical and experimental models developed for the prediction of thermal interactions of an automobile passenger with the cabin environment and a ventilated seat. The mathematical model developed in this work employs existing and modified human-body heat balance equations along with variable thermo-physical environmental conditions. The model predicts steady-state and transient variations of passenger skin and seat-surface temperatures with time before and after activating the seat ventilation system for the given and selected cabin air conditions and heated seat temperature. In calculating the temperature changes with time after activating the ventilated-seat system, the modified heat balance equation along with the numerical analysis using the CFD package (Fluent, v.6) has been iteratively used, in which appropriate air-side average heat transfer coefficients were determined by using the Reynolds and Nusselt analogies for various system operating conditions. An experimental chamber was built to simulate the vehicle air and seat conditions attainable during a hot summer day. A selected number of individuals have participated in the experiments. Passengers’ skin and seat-surface temperatures were measured with time after activating the ventilated-seat system for various chamber conditions. Investigation of the results obtained from the mathematical model and the experimental work showed that the seat ventilation system proposed in this work is able to provide passenger thermal comfort within a short time after activating the seat ventilation system. Detailed experimental works have been done to quantify the passengers’ thermal responses along with various chamber conditions for objective view point. Human subjective tests were done and statistically analyzed to support experimental works for subjective view point.