Effects of geometric parameters on confined impinging jet heat transfer Z.Q. Lou * , A.S. Mujumdar, C. Yap Department of Mechanical Engineering, National University of Singapore, Singapore 119260, Singapore Received 3 August 2004; accepted 29 October 2004 Abstract The objective of this work is to carry out a numerical investigation to examine the effects of geometric parameters on the confined impinging jet heat transfer. Parameters such as Nusselt number, Reynolds num- ber, H/W have been studied. Nozzle width H ranges from 0.6 mm to 2 mm, and nozzle-to-plate spacing W ranges from 0.5 mm to 10 mm. The jet flow is in the range of laminar flow with Reynolds number from 26.8 to 1000. This paper presents distributions of target surface temperature, local and average Nusselt number on the target plate. Pressure drop for different H/W is also obtained. This study can provide useful infor- mation to the application of impinging jet heat transfer in industry. Ó 2004 Elsevier Ltd. All rights reserved. Keywords: H/W; Nusselt number; Roughness 1. Introduction Jet impingement is one of the flow techniques used to cool or heat target surfaces. It is widely used in industrial applications ranging from drying of textiles and films, metal sheet manufactur- ing, gas turbine cooling etc. Recently, due to its high heat transfer rate, impinging jet heat transfer has been applied in the field of electronic component cooling. 1359-4311/$ - see front matter Ó 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.applthermaleng.2004.10.014 * Corresponding author. Tel.: +65 68744657. E-mail address: g0203712@nus.edu.sg (Z.Q. Lou). www.elsevier.com/locate/apthermeng Applied Thermal Engineering 25 (2005) 2687–2697