Research On Flow And Heat Transfer Characteristics Of Heat Sink

This paper concentrates on the study of flow and heat transfer characteristics of heat sinks which are widely used in electronic equipment cooling. The study means include the numerical simulation method and the experimental way. Because there exist many study reports about heat sink, several new angles are researched in this dissertation. In the fist aspect, the three-hole probe is used to measure the central flow field between two fins, and the purpose is to investigate flow field properties of heat sink. The second purpose is to study the heat transfer characteristics of heat sink in the local heat flux. In the following step, a set of three-dimensional mathematical model involving the heat transfer of the heat sink turbulent flow and heat conduction coupling, and the experimental conditions are simulated with this model. In the fourth aspect, flow methods are researched because they affect heat sink' heat transfer properties. The fifth purpose is to study the flow and heat transfer characteristics of the different fin forms. In the last aspect, a set of optimum design model of heat sink is developed. The flow field vector maps are given by experimental results. The results show that there exists circuitous flow in the central surface between two fins and that the heat transfer characteristics in the local heat flux are greatly different from the heat transfer characteristics in the average heat flux. In the numerical study, a set of three-dimensional mathematical model is established according to Navier-Stokes equations. The mesh is generated in multi-blocks, and the k ~ε model is used to simulate the airflow. The non-lines equations are calculated by SIMPLEC arithmetic. In order to obtain a higher accurate result, the convection terms of equations is treated by QUICK scheme. The simulative results are as compared with the experimental results proves that the mathematical model is accurate. The experimental results also show that heat transfer properties in the lengthways are better than them in the crossflow. The simulative results display that appropriate flow paths can intensify heat transfer. For an electronic equipment with heat sink, the optimum geometries of heat sink with the minimal thermal resistance is obtained by means of the Genetic Algorithms. And the feasibility of results should be confirmed by experiment.