Time reduction in a forced-convection thermal process using simplified transient analysis

This study investigates the utilisation of a simplified model in the transi ent analysis of a thermal cooling process. In such process the external the rmal resistance between the surface and the surroundings is high compared t o the system internal thermal resistance, so that the first controls the he at transfer process. In this case the Biot number is lower than 0.1. Alumin ium reels were utilised, which, with proper internal instrumentation, furni shed experimental results for the thermal cooling process. Based on experim ental data, a simplified model for the determination of the process film co efficient was used. Subsequently, experimental and theoretical results were compared. The change of the airflow direction was also investigated for th e cooling process, aiming at process time optimisation. (C) 2001 Elsevier S cience Ltd.