Experimental and numerical investigation of the influence of varying micro-channel width on flow and heat transfer uniformity

This study integrates experimental and numerical methods to investigate the heat transfer and flow characteristics of microchannel heat sinks with varying width distributions. Water is used as the working fluid and laminar flow model is applied for simulation. Specifically, ten different width distribution structures were designed, including uniform-width configurations and nine non-uniform-width structures (I to IX) with progressively refined intermediate channel widths. Numerical simulations were employed to analyze the flow and heat transfer behaviors, and experimental validations were conducted on both the uniform-width structure and structures II, IV, V, VI, and IX. Results indicate that in uniform-width channel structures, the pressure drop and mass flow rate in intermediate channels exceed those in side channels, resulting in uneven temperature distribution at the base. Conversely, refining the intermediate channel widths under constant total width promotes more uniform flow and wall temperature distributions. A Performance Evaluation Criterion for Non-uniform Channels (PECNC) was introduced to identify the optimal structure. Ultimately, structure VI, characterized by continuously refined intermediate widths, emerged as the optimal design for achieving uniform temperature distribution. A mathematical expression for calculating the optimal microchannel width distribution conducive to uniform temperature distribution was also established.