An experimental and numerical investigation of tube bank heat exchanger thermofluids

Heat exchangers are extensively used in engineering applications, such as for the thermal management of electronic cabinets. Although computational fluid dynamics (CFD) has the potential to provide a more accurate assessment of exchanger thermal performance than empirically-based software, CFD-based parametric analysis of a wide range of exchanger geometries and Reynolds numbers can be computationally prohibitive. This paper proposes and assesses the effectiveness of a dual design strategy, which combines empirical and numerical analyses of heat exchanger thermofluid performance. Empirical analysis serves to provide initial design specifications, while performance is optimized using CFD. The test vehicle consists of a staggered tube bank heat exchanger arrangement (S_T* = S_L* = 3.0). Good agreement is obtained between the empirical relationships developed by Martin [1] for heat transfer and Gaddis and Gnielinski [2] for pressure drop, and corresponding CFD predictions for Reynolds numbers varying from 1,749 to 17,491. Numerical flow field predictions are found to be accurately predicted relative to particle image velocimetry (PIV) measurements for a Reynolds number of 700. This study therefore provides a degree of confidence in using empirical correlations to undertake an initial sizing of tube bank heat exchanger design, to be refined for application specific environments using CFD analysis.