Forced convection air cooling characteristics of plate fins for notebook personal computers

Three-dimensional laminar flow simulation was carried out in order to investigate forced convection air cooling characteristics of compact plate fin arrays expected to be used for cooling notebook personal computers under the condition for which the fin tips were shrouded and no spanwise space around the fins was provided. The numerical simulation was performed by considering a conjugate problem which solved both flow and heat transfer in air stream and heat conduction in the fins and fin bases. Numerical results showed that the average heat transfer coefficient of the fin base was approximately one half of that of the fin. Based on the results of computation, some empirical equations for average Nusselt number of the fins and the fin bases and the friction factor were proposed as a function of Reynolds number. Using the fin efficiency calculated on the basis of the conventional conduction fin model, the thermal resistance of the plate fins could be estimated easily on the basis of the above-mentioned equations within an error level of 5% compared with the numerical results. The results also led to an important finding that there existed an optimum fin spacing fora given heat flux which could minimize blowing power