| With the rapid development of electronic technology,the integration degree of CPU chip is higher and higher,the power of the chip is increasing,and its heat output is also higher and higher.The working temperature of CPU directly affects the stability and service life of computer.If the temperature of CPU increases,the running speed of CPU will decrease.In order to make the CPU work in the normal temperature range,it is necessary to use CPU heat sink with high efficiency.With the advantages of small size,compact structure and high heat dissipation efficiency,centrifugal CPU radiator has been widely used in light and thin notebook computers.In this paper,the physical and mathematical model of the centrifugal radiator is established according to the heat dissipation demand of the light notebook computer.The heat transfer and flow of the radiator are simulated by FLUENT software.The efficiency of the centrifugal fan and the comprehensive heat dissipation performance of the radiator are analyzed.The centrifugal radiator is optimized from the perspective of the centrifugal fan and the fins.The main contents of this paper are as follows:First of all,a three-dimensional physical and mathematical model of engine 27 1u radiator is established,numerical calculation is carried out,and the heat dissipation mechanism is analyzed through the distribution ofconvection field and temperature field;the experimental test is carried out with bare metal platform test,and the experimental results are compared with the results of numerical calculation,which verifies the correctness with the results of numerical calculation,which verifies the correctness and feasibility of the model and calculation method;Then,the number of blades,the installation angle of blade outlet,the installation angle of blade inlet and the length of short blade are selected to establish different centrifugal fan models,and the orthogonal experimental analysis of four factors and three levels is carried out.The results show that too large or too small blade clearance can significantly reduce the mass flow rate,and the factors affecting the efficiency performance of the design parameters of the fan impeller are: number of blades,installation angle of blade outlet,short blade length,installation angle of blade inlet.At 2500 rpm,taking the total pressure efficiency of the centrifugal fan as the evaluation index,the optimal combination of the structural parameters of the centrifugal fan is obtained: the number of blades is 18,the installation angle of the inlet is 53°,the installation angle of the outlet is 60%,and the length of the short blade is 25 mm.Finally,the long blade of the optimized fan is changed from arc curve to S-shape.Compared with the original fan,the air volume is increased by2.51% and the efficiency is increased by 15.1%.Combined with the optimized fan,the fin shape is changed from straight line to arc curve and staggered distribution.The results show that the fin can significantly improve its heat dissipation performance.For 65 W CPU,the temperature of CPU can be reduced from 74.68℃ to 68.58 ℃,and the heat dissipationefficiency can be increased by 8.2%,so that the CPU can keep in the normal working range for a long time.In this paper,the numerical simulation of the centrifugal CPU radiator is carried out,and the influence of various factors on the cooling performance is analyzed and optimized,which has certain academic significance and engineering application value. |
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