Enhanced multi-objective optimization of a microchannel heat sink through evolutionary algorithm coupled with multiple 
surrogate models

Abstract

A liquid flow microchannel heat sink has been optimized with the help of three-dimensional numerical analysis and multiple 
surrogate methods. Two objective functions, thermal resistance and pumping power have been selected to assess the performance 
of the microchannel heat sink. The design variables related to the width of the microchannel at the top and bottom, depth of 
the microchannel, and width of fin, which contribute to objective functions, have been identified and a three-level full factorial 
design was selected to exploit the design space. The numerical solutions obtained at these design points were utilized to construct 
surrogate models, namely Response Surface Approximations, Kriging and Radial Basis Neural Network. A hybrid multi-objective 
evolutionary algorithm coupled with surrogate models is applied to find out global Pareto-optimal solutions. The accuracy of the 
surrogate models has been discussed in view of their predictions and trade-off analysis was performed in view of conflicting nature 
of the two objectives. The Pareto-optimal sensitivity of the design variables has been found out to economically compromise with the 
design variables. The application of the multiple surrogate methods not only improves quality of multi-objective optimization but also 
gives the feedback of the fidelity of the optimization model.