Selection of Appropriate Estimation Criteria in Flow Simulation Study for Predicting Cooling Efficiency of Ventilated Protective Clothing

Abstract A Computational Fluid Dynamics (CFD) is utilised in various research and engineering areas across multiple fields and industries. The research field of ventilation and indoor air science has experienced a significant surge in scientific articles focused on the utilisation of CFD. With the solution of increasingly complicated ventilation problems, CFD validation and verification are more important than ever. The present study focuses on the crucial task of selecting suitable criteria in a flow simulation analysis aimed at predicting the cooling efficiency of ventilated protective clothing. This study examines three different cases of a simplified elliptical model of the human body with a protective jacket comprising 11, 48, and 105 ventilation elements. SolidWorks Flow Simulation is used to simulate all three models individually to calculate values of eight different criteria. It is assumed that increasing the number of ventilation units would result in an enhancement of cooling efficiency. However, it is crucial to understand how the values of various criteria change in flow simulation studies under different situations, and which criteria are crucial for the analysis. The criteria values for three cases are recorded and compared. The analysis results indicate a gradual increase in values of heat transfer rate, pressure and temperature differences as the number of ventilation units increases. However, certain parameter values like flow pressure difference do not provide sufficient information to predict efficiency of the system, whereas a parameter like average temperature shows low sensitivity. The study suggests that the heat transfer rate and heat flux are the most appropriate criterion to be examined in such a situation. This is due to the fact that an increased heat transfer rate from the body signifies a more effective cooling mechanism.