Numerical heat transfer analysis and development of a heat removal system for an unshaded parked car in sunny day: computational fluid dynamics study

Abstract

Increase in air temperature inside a parked car cabin causes negative impacts such as low thermal comfort, health risk for the passengers/pets inside the cabin, increased fuel consumption due to higher air-conditioning requirements. The present project focuses on methods to reduce the cabin temperatures for a car parked in unshaded condition. CFD analyses along with experimental validation have been performed with the use of different proposed cabin temperature control methods such as use of electrochromic tint on windshield, use of inlet and outlet vents, lowering of windows and combinations of these. Commercial CFD package ANSYS Fluent has been utilized to develop a numerical model for car cabin temperature distribution assessment when a parked car is subjected to solar load at different locations inside the cabin such as dashboard, seats and boot. A solar surface to surface radiation model is used in conjunction with solar calculator to capture the solar radiation that included change in position of the sun. A 5:1 scale down model of car cabin has been used for experimental validation with the help of help of PT-100 resistance thermometers. Good reduction in cabin temperatures has been observed for all the proposed cooling methods with 14 °C reduction for the combined tint, vents and lowered windows case.