基于流-固-热三场耦合模型的不同蜂窝单元相变石蜡熔化特性OA

Metal honeycomb structures are characterized by light weight,large surface area,and excellent thermal conductivity.When combined with phase change materials(PCMs),the inherent drawback of low thermal conductivity in pure PCMs can be effectively mitigated.This study focuses on the unconstrained melting behavior of PCMs in honeycomb cells with different shapes.The effective heat capacity method is adopted to account for latent heat storage during the solid-liquid phase change process.The Boussinesq approximation is introduced to describe natural convection in the liquid phase driven by buoyancy.A fluid-solid-thermal multiphysics coupled numerical model is established and validated experimentally.Based on the validated model,the melting processes of phase change paraffin in five types of honeycomb cells(triangular,rhombic,rectangular,hexagonal,and circular)are systematically analyzed.The results show that natural convection significantly accelerates heat transfer in paraffin and enhances the melting rate.Throughout the entire melting process,the effect of natural convection in the triangular cell is significant,reducing the total melting time by 92%compared with the case without natural convection.The cell arrangement mode and geometric shape of the cell have significant effects on melting efficiency.Specifically,the average melting rate of the inverted triangular unit is increased by 38.58%compared with that of the upright unit.In addition,as the unit configuration with the highest melting rate,the triangular unit shows improvements of 12.03%,16.56%,21.25%,and 16.11%,respectively,compared with the classical hexagonal honeycomb unit under different height-to-width ratios.Using the enhancement ratio as the criterion,the triangular unit achieves the highest melting rate at a height-to-width ratio of 1.0,with the complete melting time reduced by 21.25%.