Performance Of Rectangular Fin Research Articles

An investigation of channel blockage effects on hydrogen mass transfer in a proton exchange membrane fuel cell with various geometries and optimization by response surface methodology

A 2D mathematical modeling was developed to analyze the mass transport in a proton exchange membrane fuel cell. The pin fins were inserted in the flow channel to improve reactant gas distribution in the gas diffusion layer (GDL). The effect of rectangular and triangular shape of fins and different title angles of 4, 6 and 8° on the reactant gas transport were examined. The results showed that performance of rectangular fins are better than triangular fins due to increasing reactant spread over the GDL. The effect of three independent factors including length and width of blocks and hydrogen gas velocity on the response (hydrogen gas diffusion to GDL and pressure drop in anode channel) was investigated using analysis of variance (ANOVA). The results showed that block height and hydrogen gas velocity are the most important factors affecting the responses. Also, response surface methodology (RSM) method was used to predict the optimal conditions to achieve the minimum the pressure drop and maximum the total flux magnetic H2 to GDL in anode channel. The result of the optimization process shows that a gas velocity of 4.22 m/s and the block with height and width of 3 mm are the optimal conditions.

Performance of Rectangular Fin in Wet Conditions: Visualization and Wet Fin Efficiency

An experimental study concerning the performance of a rectangular fin in both dry and wet condition was carried out. The visual observation of the dehumidifying phenomenon identified four regions, including the fully dry, very fine droplet, larger droplet, and film-like region. Experimental results showed that the effect of dry bulb temperature on the wet fin efficiency is very small. The dry fin efficiency is about 15–25 percent higher than that of the corresponding wet fin efficiency. For fully wet condition, the effect of relative humidity on the fully wet fin efficiency is also small. For partially wet surface, a considerable influence of the relative humidity on the fin efficiency is encountered. Test results for the fully wet fin efficiency agree well with some of the previous studies but disagree with some of the previous investigations. The main cause to this controversy may be attributed to the formulation of the relation between the humidity ratio and the fin temperature. The fully wet fin efficiency decrease slightly with increase of fin base temperature. However, the effect of fin base temperature on the dry fin efficiency is relatively small.

An experimental investigation on performance of rectangular fins on a horizontal base in free convection heat transfer

This paper reports an experimental study of free convection heat transfer from rectangular fin-arrays on a horizontal base. An experimental set-up was constructed and calibrated, 15 sets of fin-arrays and a base plate without fins were tested in atmosphere. Fin height was varied from 6 mm to 26 mm, fin spacing was varied from 6.2 mm to 83 mm. The base-to-ambient temperature difference was also varied independently and systematically with the power supply to heater ranging from 8 W to 50 W. Fin length and fin thicknesses were fixed at 100 mm and 3 mm, respectively. The experimental program was conducted so as to clearly delineate the separate roles of fin height, fin spacing and base-to-ambient temperature difference. It was found that for a given base-to-ambient temperature difference the convection heat transfer rate from fin-arrays takes on a maximum value as a function of fin spacing and fin height. For a given base-to-ambient temperature difference the enhancement of the convection heat transfer rate of fin-arrays relative to that for base plate without fins is strongly dependent on the fin spacing to fin height ratio and number of fins. A correlation was also presented relating the convection heat transfer rate of fin-arrays relative to that for base plate without fins with the relevant non-dimensional parameters.