Pengujian Karakteristik Perpindahan Panas Dan Faktor Gesekan Dari Sirip-Sirip Pin Silinder Susunan Segaris Dalam Saluran Segiempat

Abstract

Abstract : Surface heat transfer extension using fins often used in heat exchanger equipment to enhance heat transfer. This research was conducted to investigate the characteristics of heat transfer and pressure drop as well as thermal performance of inline cylindrical pin fin assembly in rectangular channel. It was used cylindrical pin fins with 12.7 mm of diameter and 75 mm of height. The parameters of this research were Reynolds number (3,000 – 37,500), depending on the averaged inlet air velocity and hydraulic diameter, the interfin pitch distance in the spanwise direction (Sx/D) which was kept constant at 2.95 and the interfin pitch distance in the streamwise direction (Sy/D = 1.97 – 3.94). The experimental result shown that increasing Reynolds number (Re) and decreasing the interfin pitch distance in the streamwise direction (Sy/D) increased the average convection heat transfer coefficient (h) and Nusselt number (Nu). The pressure drop (P) and friction factor (f) decreased while the interfin pitch distance in the streamwise direction (Sy/D) increased. Increasing Reynolds number would decrease thermal performance (). At Sy/D = 1.97 for Re > 24,900, and Sy/D > 1.97 for Re > 12,400, the values of  were less than 1, i.e. the used of pin fin assembly would cause an energy loss rather than gain. The net energy gain ( was greater than 1) was only at Sy/D = 1.97 for Re < 24,900, and at Sy/D > 1.97 for Re < 12,400. A net energy gain up to 28 % was achieved at Sy/D = 1.97 for Re = 3,076.

Keywords : Pin Fin Rectangular Channel Reynolds Number Friction Factor Thermal Performance