This study aims to optimize energy transfer and thermodynamic irreversibility in a nanofluid-cooled micro-heat-exchanger (MHE) with jet flow. It analyzes the effects of Richardson number (Ri), Knudsen number (Kn) and inclination angle (a) on heat transfer and entropy generation to determine optimal operating conditions. The results provide insights for designing efficient microcooling systems in electronics and microfluidics applications.
Box-Behnken design of experiments (DoE) and single relaxation time-lattice boltzmann method (SRTLBM) simulations studied Ri (0.64–1.79), Kn (0–0.1) and a (0°–45°). Response surface methodology analyzed impacts on isotherms, Nu and S_gen. Second-order polynomial models optimized heat transfer vs irreversibility. 3D/2D contours showed parameter interactions, and analysis of variance (ANOVA) validated models.
The analysis reveals that increasing the inclination angle (a) improves heat transfer but raises entropy generation (S_gen). In contrast, higher Richardson (Ri) and Knudsen (Kn) numbers reduce thermal efficiency, decreasing the average Nusselt number (Nu_avg) by 52.5% and entropy generation (S_gen) by 79.1%. Nonlinear relationships between parameters, Nu_avg and S_gen were confirmed via ANOVA, underscoring the complex heat-flow interactions. Optimal conditions (Ri = 1.7898, Kn = 0.0212, a = 45°) maximize heat transfer (Nu_avg = 22.1847) while minimizing irreversibility (S_gen = 28.553). Despite higher dissipation in inclined configurations, thermal performance improves. Post-optimization validation shows strong agreement between simulations and DoE predictions.
This work uniquely integrates statistical DoE with LBM simulations to optimize nanofluid-cooled MHEs, addressing gaps in multi-parameter analysis. The study offers practical benchmarks for designing sustainable thermal management systems. Quantifying interactions between Ri, Kn and a, advances fundamental understanding of nanofluid dynamics in microscale applications, with direct relevance to electronics cooling and microfluidic technologies.
