Heat Transfer Characteristics of Microjet Impingements with Flow Extraction

Abstract

The present study proposes a novel microjet impingement-effusion model for electronics cooling. The model is realized on a silicon substrate with the arrangement of impinging and extraction holes. A conjugate heat transfer analysis is carried out which includes heat transfer from the substrate base to the impinging fluid which subsequently taken away through the extraction holes. The impingement microjet is surrounded by six micro holes distributed hexagonally to extract the spent flow. A three-dimensional (3-D) numerical analysis is performed for a single-phase steady state laminar flow in view of the small flow rates and micro scales. The proposed model is investigated for local temperature and heat transfer coefficient distribution. The highest temperature is observed near the impingement, and the lowest temperature is observed on the surface below the extraction holes. With the increase of jet-to-effusion hole diameter square ratio, the high-temperature region is reduced. However, there is no significant improvement is detected in the local heat transfer coefficient.