非对称凹腔橫向阵列压电风扇强化冷却特性研究  

Enhanced Cooling Characteristics of Asymmetrical Concave Transverse Array Piezoelectric Fan

作　　者：张冬冬 谭晓茗[2] 张靖周[2] 鹿世化[1] 李鑫郡 ZHANG Dongdong;TAN Xiaoming;ZHANG Jingzhou;LU Shihua;LI Xinjun(School of Energy and Mechanical Engineering,Nanjing Normal University,Nanjing 210042,China;College of Energy and Power Engineering,Nanjing University of Aeronautics&Astronautics,Nanjing 210016,China;Key Laboratory of Aerospace Power System,Nanjing University of Aeronautics&Astronautics,Nanjing 210016,China)

机构地区：[1]南京师范大学能源与机械工程学院,南京210042 [2]南京航空航天大学能源与动力学院,南京210016 [3]南京航空航天大学航空动力系统重点实验室,南京210016

出　　处：《南京航空航天大学学报》2022年第4期635-643,共9页Journal of Nanjing University of Aeronautics & Astronautics

摘　　要：基于压电风扇振动拟合函数,利用动网格技术针对多压电风扇系统冷却非对称凹腔结构的三维非定常流动和换热特性开展数值研究,重点阐释了凹腔相对曲率Kr和多风扇振动相位差φ的影响。研究结果表明:凹腔表面时均对流换热系数的非对称分布特征是由于展向相邻风扇相互作用和弦向表面不对称耦合作用引起的;特别是当Kr值降低至2时,非对称凹腔表面时均对流换热系数的非对称分布特征将完全消失,此时振动包络内的传热系数几乎是Kr=6时的两倍;多风扇系统同相振动时(φ=0°,即相邻风扇起振相位相同)所激励的脱落涡尺度明显强于反相振动情况(φ=180°,即相邻风扇起振相位相差180°),使得同一凹腔内同相振动(φ=0°)时包络区内的换热能力明显优于反相振动(φ=180°),此外由于同相振动(φ=0°)产生的间隙涡也增加了邻近风扇间隙内的换热能力。A numerical investigation of the 3D unsteady flow and heat transfer performance induced by multipiezoelectric fans on cooling asymmetrical concave surfaces is performed using dynamic meshing scheme according to its vibration fitting function.The effects of the relative curvature(Kr)and vibration phase difference(φ)on heat removal performance are described.The results show that the asymmetrical nature of the time-averaged convective heat transfer coefficient distributions is mainly due to a combination of the interaction of neighboring fans in the spanwise direction and the asymmetry of the surfaces in the chordwise direction.In particular,when Kr is decreased to 2,the asymmetry of distribution almost entirely disappears,and the heat transfer coefficient in the vibration envelopes is almost twice that of Kr=6.Since the characteristic scale of the shedding vortex excited by multi-fan vibrating in-phase(φ=0°,the phase difference between adjacent fans is 0°)is larger than that of out-of-phase(φ=180°,the phase difference between adjacent fans is 180°),that the heat transfer capacity in vibration envelope under in-phase(φ=0°)is significantly better than that under out-of-phase(φ=180°).In addition,the gap vortices generated by the inphase vibration(φ=0°)also increase the heat transfer capactity in the adjacent fan gap.

关 键 词：多压电风扇 非对称凹腔 对流换热系数 数值模拟 实验验证 

分 类 号：TH42[机械工程—机械制造及自动化]