Heat flux performance of a pin-finned ice heat sink

Richards, Orji Ugochukwu and Amiolemhen, Patrick Ejebheare and Ebhojiaye, Raphael Slvester and Faith, Ogbodo Ifeyinwa (2025) Heat flux performance of a pin-finned ice heat sink. World Journal of Advanced Engineering Technology and Sciences, 14 (3). pp. 221-229. ISSN 2582-8266

The research was aimed at enhancing the thermal performance of a modified engine block of the ICE of motorcycle to increase heat flow to the ambience. The internal combustion engine is a self-propelled system capable of converting chemical energy to huge amount of heat and mechanical energy, therefore to regulate this enormorse value of energy, design and development of a thermally effective and efficient component is critical to prolong the engine life and assures smooth functionality. The design of the internal combustion motorcycle engine heat sinks generally direct effort to increase heat flux to the ambience – this was carried out by augmenting the surface area and geometry of the experimental sample of an identified engine block (Errand 125-CT) motorcycle engine block (lower block). Three samples of the lower block were used to accomplish the experiments objectives. The horizontal projecting straight rectangular fin were ground inward normal to the vertical cylindrical wall through a perimeter of 35.2cm each for a number of the rectangular fins less the topmost and bottommost fins. The grinding was carried out for samples B and C through a depth of 1.5 and 3.0mm except for samples A which is the original (control) sample. Drilling machine was used to create holes of diameter 4.01mm in a vertical orientation on the horizontally projecting rectangular fins. A number of 0, 60 and 120 pin fins were pushed/hammered vertically into the drilled holes to manipulate both surface the surface area and fin geometry. The sample A, B and C were placed for ten minutes each in an electric klin till the pyrometer (IR thermometer) indicates a temperature of 100 ℃. The top and bottom cylinder core were covered with the aid of a wooden slab of diameter 5.18cm before placing them in the axial air flow facility at the air speed of 0 ,10 and 20m/s in turn. A digital stop watch and pyrometer were used to note the time for the samples to cool from 80 to 300C in an axial air pumping machine at varied velocity field. Sample A, B and C has a total of 0 ,60 and 120 number pin fins respectively each sample has mass of approximately 1160.02 grammes. From observation sample C, took a period of 529.9, 663 and 2308 seconds to cool from 80 to 300C in a velocity field of 20, 10 and 0m/s respectively. Sample B, took a period of 558.0, 680 and 2363 seconds to cool from 80 to 300 C respectively. Sample A (zero pin fins) took a period of 586, 703 and 2439.2 seconds to cool from 80 to 300 C respectively at an air velocity of 20 ,10 and 0m/s respectively. Two parameters, including thermal effectiveness and efficiency were applied to evaluate the fin performance as a ratio of the original fin (control sample) the effectiveness of modified pin fin samples at 20m/s for sample A, B and C indicated 1.000, 1.0322 and 1.0610 for effectiveness; 1.000, 1.087 and 1.1576 for efficiency ratio in the same order. Therefore, an increased pin number and air velocity clearly improve the thermal performance of air-cooled engines.