Heat Transfer Augmentation using Almond Dimple Tubes with Random Arrangement

Abstract

Objective of the present project work was to design, manufacture and evaluate the performance of a cross- flow heat exchanger using plain tube and almond dimple randomly arrangement. Air and Water were the fluids used to carry out test. The objective was to analyse the effect of gas flow over two different tubes. The mass flow rate of air was varied such that the Reynolds number was in between 10000 to 37000. Since the objective is to analyse the performance of gas flow over tubes, the tube side fluid flow condition was kept constant. Comparisons of experimental results for Plain and almond tube when randomly arranged. The performance parameters related to heat exchanger such as pressure drop, overall heat transfer coefficient, heat duty have been reported in this work. Pressure drop found to be more in case of almond dimple tubes when compare with plain tube. The overall heat transfer co- efficient is found to increase while using almond shaped dimpled tubes over plain tubes, which is more pronounced at higher Reynolds number. Pressure drop in case of almond dimple tubes is more as compared to plain tube, due to more turbulence. Heat loss is less in case of dimple tubes as compare to Plain tubes.