3D-printed tubes with complex internal fins for heat transfer enhancement—CFD analysis and performance evaluation

Abstract

Additive manufacturing (AM), also known as 3D printing technology, is applied to fabricate complex fin structures for heat transfer enhancement at inner surface of tubes, which conventional manufacturing technology cannot make. This work considered rectangular fins, scale fins, and delta fins with staggered alignment at the inner wall of heat transfer tubes for heat transfer enhancement of internal flows. Laminar flow convective heat transfer at 500 < Re < 2000 has been numerically studied, and heat transfer performance of the tubes with 3D-printed interrupted fins has been compared to that with conventional straight continuous fins and smooth tubes. The benefit from heat transfer enhancement and the loss due to increased pumping pressure is evaluated using the total entropy generation rate in the control volume of heat transfer tube. The heat transfer coefficient in tubes with interrupted fins in staggered arrangement can have 2.6 times of that of smooth tube and 1.4 times of that with conventional continuous straight fins. The entropy generation in the tubes with interrupted fins in staggered arrangement only has 30-50% of that of smooth tube or tube with traditional continuous straight fins. The benefit of using interrupted fins in staggered arrangement is significant.