Study Of Heat Transfer ofaA Solid With Protective Fabric Under Hot Air Jet Impingement

Abstract

This research focused on the experimental analysis of the thermal response of a solid base plate (mimic to skin) and also the performance of fire protective fabric under hot air jet impingement situation. This investigation utilized a fabricated attachment with an axial flow wind tunnel for horizontal hot air jet of different velocities and temperatures that impinged on vertical base plate. The experiments were conducted without fabric, cotton fabric and fire protective fabric to understand the unprotected situation as well as protective condition. The air jet temperatures were 115oC and 125oC. The hot air jet velocities were 12, 15, and 19 m/s at the exit point of the nozzle. The variations of the nozzle-to-plate separation were 2, 4 and 6 with respect to nozzle diameter. The fabrics were placed in contact and 6 mm away from the base plate during the experiments. Seven thermocouples were employed at different radial locations of the base plate to measure the surface temperatures of the solid base plate by using data acquisition system. The surface temperatures were used to calculate the surface heat flux, local heat transfer coefficient, and Nusselt numbers at different nozzle-to-plate separations. The experimental results show the maximum decrease of heat flux by using the protective fabric. The significant heat transfer was also occurred for cotton fabric. In addition, the heat transfer through the fabric was also observed, which varied on nozzle-to-plate separation and Nusselt number.