Multi-fidelity topology optimization of flow boiling heat transfer in microchannels

TL;DR

This paper introduces a multi-fidelity topology optimization approach for designing microchannel structures that enhance flow boiling heat transfer, significantly improving thermal performance and efficiency.

Contribution

A novel multi-fidelity topology optimization method with a specially designed objective function for flow boiling in microchannels is developed, reducing computational cost and improving design quality.

Findings

Optimized microchannel structures eliminate hot spots.

Thermal resistance is significantly reduced.

Temperature uniformity is improved.

Abstract

Topology optimization (TO) is a powerful method to design innovative structures with improved heat transfer performance. In the present study, a multi-fidelity TO method with a delicately defined objective function is developed for flow boiling heat transfer in microchannels. Low-fidelity TO is conducted for the reduced-order process of single-phase laminar convective heat transfer, which generates a set of structure candidates for subsequent high-fidelity evaluation of flow boiling heat transfer. To avoid the possible iteration between the low-fidelity TO and high-fidelity evaluation which leads to inefficient solution of the multi-fidelity TO, distributions of velocity, temperature and two-phase in microchannels with single-phase and/or flow boiling heat transfer are investigated and compared in detail, based on which a new objective function is delicately defined, which can be employed in the low-fidelity TO yet can stand for the performance of the high-fidelity problem. With the help of the new objective function, the efficiency of the multi-fidelity TO is significantly improved and TO structures are designed with hot spots eliminated, thermal resistance reduced and temperature uniformity improved. The present work provides a new method for TO of complicated heat and mass transfer problems. Keywords: topology optimization, flow boiling, multi-fidelity optimization, microchannels, convective heat transfer