A Numerical Study on Heat Transfer Enhancement of Automobile Thermoelectric Generator

Abstract

The paper presents a numerical simulation to investigate the heat transfer enhancement of a rectangular pipe with longitudinal fins for the automobile thermoelectric generator. The fins were inserted near the pipe wall. The effects of flow rate (wi=10m/s-50m/s), fin length ( l=100, 133, 200, 400), fin spacing (d=20, 30, 40, 50), fin height (h=20, 30, 40, 50) on Nusselt number (Nu), friction factor (f) and overall enhancement ratios (ƞ) are investigated under constant wall temperature , using air as woking fluid. Number calculations were performed with FLUENT code. The obtained results reveal that all geometric parameters have important effect on the thermal performance of pipe, and the finned pipe show better thermal performance than smooth pipe. It is also found that the overall enhancement ratios increase with increasing fin length and fin height, also the overall enhancement ratios decrease with increasing fin spacing. All finned pipes have good heat performance with ƞ greater than 1. The best overall enhancement of 1.25 was achieved for wi=10m/s for which the fin dimensions is l = 400mm, d = 20mm, h = 50mm.