Heat Transfer Enhancement by Microstructured Surfaces

This thesis was performed in the multi-Scale ModeLing Laboratory (SMaLL) of the Energy Department at Politecnico di Torino. Part of this thesis was also conducted in the Computational Multiphase Transport Laboratory of the University of Illinois Chicago (UIC). The modeling activity here proposed fits into the THERMALSKIN project (www.thermalskin.org). The target of this work is to model by means of the software FLUENT the heat transfer enhancement obtained by the application of micro-structures manufactured by Direct Metal Laser Sintering (DMLS) on a sample top surface. In the first part, a concave micro-Venturi geometry was studied. Although the modelling activity shown modest results, these ones have been denied by the experimental evidences. In the second part, new rough geometries by DMLS were tested and modeled using both a 2D and a 3D approach. These rough surfaces shown very promising heat transfer enhancements. A theoretical method was developed in order to evaluate the thermal behavior of these surfaces. The modeling activities seems to estimate well and confirm, with a good approximation, the experimental results.