单个压电风扇传热特性  

Characteristics of heat transfer with single piezoelectric fan

作　　者：李鑫郡 张靖周[1] 谭晓茗[1] 

机构地区：[1]南京航空航天大学能源与动力学院,南京210016

出　　处：《航空学报》2017年第7期205-214,共10页Acta Aeronautica et Astronautica Sinica

基　　金：国家自然科学基金(51106073);中央高校基本科研业务费专项资金(NS2014018)~~

摘　　要：基于压电风扇运动规律的激光多普勒测振仪测试结果,利用动网格技术对单个垂直壁面压电风扇的三维非定常流动和传热特性进行了数值模拟,同时应用红外热像仪对表面局部对流换热系数分布进行了测量。研究结果表明:时均对流换热系数的数值模拟与实验结果具有良好的一致性;加热表面的存在,导致压电风扇激励的涡系结构与其在自由空间振动时诱导的流场存在一定的差异,脱落涡相比于自由空间时更易于破碎;压电风扇振动诱导的涡冲击加热表面所形成的近壁流动呈现出明显的平行于风扇的侧向流动,而在压电风扇两侧边则出现卷吸的特点,叶尖包络区对应的壁面局部对流换热有显著的强化作用,表面对流换热系数分布在包络区外围呈现出明显的哑铃状特征。A numerical simulation of the three-dimensional unsteady flow and heat transfer characteristics of a single piezoelectric fan arranged normally to the heated surface is performed using dynamic meshing scheme.The displacement of the vibrating fan is determined from the vibration test by using the laser doppler vibrameter.An experimental test for the distribution of the local convective heat transfer coefficient is also made using the infrared camera.The distribution of the cycle-averaged local heat transfer coefficient obtained by the numerical simulation is found to be in good consistence with the test result.Due to the existence of the heated surface,the vortical structures excited by the piezoelectric fan behave somewhat differently from those observed in the free space.The shedding vortex is easier to be broken down in relation to the case in the free space.The near-wall flow field induced by the piezoelectric fan demonstrates obvious lateral flow parallel to the fan,and suction flow on both sides of the fan.The local convective heat transfer in the fan-tip vibration envelope is effectively enhanced.Dumbbell-shaped distribution of local convective heat transfer around the fan-tip vibration envelope is demonstrated.

关 键 词：压电风扇 对流换热 数值模拟 振动测试 换热系数 

分 类 号：O354[理学—流体力学] V231.11[理学—力学]