PERFORMANCE ANALYSIS OF INCLINED MICRO-JET IMPINGEMENT HEAT TRANSFER IN MICROCHANNEL USING COMPUTATIONAL FLUID DYNAMICS

Abstract

The increasing need for efficient cooling methods in electronic chip systems has created a surge in demand for effective solutions to tackle the challenges associated with heat dissipation, This research project focuses on conducting a comprehensive analysis of heat exchange in a microchannel by Computational Fluid Dynamics (CFD) with inclined micro-jet impingement. The aim is to explore the thermal characteristics of hexagonal cross-section jets in order to enhance cooling efficiency for electronic chip applications. The analysis involves the utilization of CFD to solve the steady, incompressible, and laminar flow equations, specifically the Three-Dimensional Navier-Stokes equations. The investigation encompasses various micro-jet arrangements, including parallel and staggered configurations consisting of four, five, nine, thirteen, and sixteen impingements. The jet inclination is maintained at a constant angle of 45 degrees with respect to the impingement surface. The cross-section of the jet nozzle is modelled as a hexagon, with different edge lengths of 60, 80, and 100 microns. The primary objective is to assess and compare the performance of these configurations, gaining valuable insights into their heat transfer capabilities. The obtained results reveal significant findings regarding the cooling performance. !I is observed that the average exit liquid temperature increases as the number of jets in the impingement array increases. This behaviour can be attributed to the increased heat transfer surface area available for dissipation as the number of jets grows. The larger surface area facilitates enhanced convective heat transfer, resulting in a higher average exit liquid temperature. Consequently, the findings suggest that higher jet densities can provide improved cooling performance in electronic chip applications. Among the investigated microjet array configurations, the inclined microjet impingement heat sink with 1 jets demonstrates superior potential compared to other configurations. This particular array design outperforms the rest in terms of its cooling capabilities. The inclined arrangement, coupled with the optimal number of jets, enables the generation of strong impingement forces, facilitating effective heat (iv)

transfer at a higher rate. The result is an enhanced convective heat transfer process, leading to a reduction in the average exit liquid temperature. The research involves the use of CFD simulations using ANSYS Fluent to analyze the cooling performance of the hexagonal cross-section jets. The simulations are conducted to study the effect of various parameters such as Reynolds number, nozzle-to-chip spacing, and jet diameter on the cooling efficiency of the system. The study also includes experimental validation of the simulation results to verify the accuracy of the CFD model. The findings of the study show that the hexagonal cross-section jets significantly improve the cooling performance compared to conventional circular jets. The results indicate that the cooling efficiency is influenced by the geometry of the hexagonal jets, as well as the operating Iarametcrs of the system. The research provides insights into the design and optimization of the cooling system for electronic devices using jet impingement, which can potentially enhance the performance and reliability of electronic devices.