Experiment on convective heat transfer of pulsed chevron jet impingement on flat plate
-
摘要:
采用红外热像测试技术对占空比(DC)恒定为0.5的冠齿脉冲射流冲击平直靶面,在不同雷诺数(5000~20000)、无量纲冲击间距(2~8)和工作频率(10~25 Hz)下进行了对流换热实验研究。结果表明:在小射流冲击间距下,冠齿脉冲射流冲击局部努塞尔数云图在射流驻点附近呈现较为明显波瓣状分布;冠齿喷管在脉冲射流冲击中依然体现出强化对流换热的作用机制,雷诺数和工作频率分别为10000和15 Hz工况下,射流冲击驻点附近的表面传热系数相对圆形脉冲射流提高幅度在20%~30%之间;在冠齿脉冲射流中,脉冲主动激励和冠齿被动诱导激励之间存在着内在的相干机制,导致其对流换热特性与冠齿连续射流和圆形脉冲射流有较大的差异。
Abstract:An experimental investigation was performed to study the convective heat transfer characteristics of pulsed chevron jet impingement on a flat plate, by using infrared imaging technique. The pulsed jet was fixed at a specific duty cycle (DC) of 0.5, the experiments were conducted under Reynolds number of 5000−20000, Dimensionless impingement spacing of 2−8 and working frequency of 10−25 Hz. Results indicated that the local Nusselt number distribution in the vicinity of jet stagnation presented a lobed pattern resembling the shape of the configuration. The pulsed chevron jet was confirmed to be capable of enhancing the jet impingement heat transfer related to the pulsed round jet. Under Reynolds number of 10000 and working frequency of 15 Hz, the convective heat transfer in the vicinity of jet stagnation could be increased by 20%−30% with the use of pulsed chevron jet, when compared with the pulsed round jet. In general, the heat transfer characteristics in the pulsed chevron jet impingement were found somewhat distinct from that in the steady chevron jet impingement as well as the pulsed round jet impingement, due to the inherent interaction of active excitation by the pulsation and passive excitation induced by chevron nozzle.
-
Key words:
- jet impingement /
- chevron nozzle /
- pulsed jet /
- flat plate /
- convective heat transfer
-
表 1 主要实验参数
Table 1. Main experimental parameters
类别 参数 数值 冠齿喷管 喷管直径 d/mm 10 喷管长度 l/mm 120 冠齿长度 a/mm 6 冠齿数 n 6 脉冲射流 频率 f/Hz 10~25 占空比 50 射流雷诺数Re 5000~20000 射流冲击距 无量纲距离H/d 2,4,6,8 -
[1] WRIGHT L S,HAN J C. Heat transfer enhancement for turbine blade internal cooling[J]. Journal of Enhanced Heat Transfer,2014,21(2): 111-140. [2] 张井山,毛军逵,李毅,等. 高压涡轮主动间隙控制机匣内部换热特性实验[J]. 航空动力学报,2014,29(2): 298-304.ZHANG Jingshan,MAO Junkui,LI Yi,et al. Experiment on heat transfer characteristics inside the casing of high pressure turbine with active clearance control[J]. Journal of Aerospace Power,2014,29(2): 298-304. (in Chinese) [3] 柯鹏,杨慧赟,王俊凯,等. 航空发动机帽罩热气膜防冰的加热特性[J]. 航空动力学报,2018,33(3): 530-539. doi: 10.13224/j.cnki.jasp.2018.03.003KE Peng,YANG Huiyun,WANG Junkai,et al. Heating characteristics of aero-engine nose cone with film-heating anti-icing system[J]. Journal of Aerospace Power,2018,33(3): 530-539. (in Chinese) doi: 10.13224/j.cnki.jasp.2018.03.003 [4] CARLOMAGNO G M,IANIRO A. Thermo-fluid-dynamics of submerged jets impinging at short nozzle-to-plate distance: a review[J]. Experimental Thermal and Fluid Science,2014,58(1): 15-35. [5] COLUCCI D W,VISKANTA R. Effect of nozzle geometry on local convective heat transfer to a confined impinging air jet[J]. Experimental Thermal and Fluid Science,1996,13(1): 71-80. doi: 10.1016/0894-1777(96)00015-5 [6] BRIGNONI L A,GARIMELLA S V. Effects of nozzle inlet chamfering on pressure drop and heat transfer in confined air jet impingement[J]. International Journal of Heat and Mass Transfer,2000,43(1): 1133-1139. [7] LEE J H,LEE S J. The effect of nozzle configuration on stagnation region heat transfer enhancement of axisymmetric jet impingement[J]. International Journal of Heat and Mass Transfer,2000,43(1): 3497-3509. [8] YU Y Z,ZHANG J Z,XU H S. Convective heat transfer by a row of confined air jets from round holes equipped with triangular tabs[J]. International Journal of Heat and Mass Transfer,2014,72(1): 222-233. [9] TRINH X T,FENOT M,DORIGNAC E. Flow and heat transfer of hot impinging jets issuing from lobed nozzles[J]. International Journal of Heat and Fluid Flow,2017,67(1): 185-201. [10] HE C X,LIU Y Z. Large-eddy simulation of jet impingement heat transfer using a lobed nozzle[J]. International Journal of Heat and Mass Transfer,2018,125: 828-844. doi: 10.1016/j.ijheatmasstransfer.2018.04.105 [11] 徐亮,任德祖,马永浩,等. 不同形状喷嘴的旋流冲击射流压力损失和传热特性研究[J]. 航空动力学报,2018,33(11): 2678-2686.XU Liang,REN Dezu,MA Yonghao,et al. Pressure loss and heat transfer characteristics experiment of swirling impinging jet with different shape nozzles[J]. Journal of Aerospace Power,2018,33(11): 2678-2686. (in Chinese) [12] VIOLATO D,SCARANO F. Three-dimensional evolution of flow structures in transitional circular and chevron jets[J]. Physics of Fluids,2011,23(12): 1-25. [13] VIOLATO D,IANIRO A,CARDONE G,et al. Three-dimensional vortex dynamics and convective heat transfer in circular and chevron impinging jets[J]. International Journal of Heat and Fluid Flow,2012,37(1): 22-36. [14] VINZE R,CHANDEL S,LIMAYE M D,et al. Local heat transfer distribution between smooth flat surface and impinging incompressible air jet from a chevron nozzle[J]. Experimental Thermal and Fluid Science,2016,78(1): 124-136. [15] GUAN T,ZHANG J Z,SHAN Y,et al. Conjugate heat transfer on leading edge of a conical wall subjected to external cold flow and internal hot jet impingement from chevron nozzle: Part 1 experimental analysis[J]. International Journal of Heat and Mass Transfer,2017,106(1): 329-338. [16] GUAN T,ZHANG J,SHAN Y. Conjugate heat transfer on leading edge of a conical wall subjected to external cold flow and internal hot jet impingement from chevron nozzle: Part 2 numerical analysis[J]. International Journal of Heat and Mass Transfer,2017,106(1): 339-355. [17] ZUMBRUNNEN D A,AZIZ M. Convective heat transfer enhancement due to intermittency in an impinging jet[J]. Journal of Heat Transfer,1993,115(1): 91-98. doi: 10.1115/1.2910675 [18] HOFMANN H M,MOVILEANU D L,KIND M,et al. Influence of a pulsation on heat transfer and flow structure in submerged impinging jets[J]. International Journal of Heat and Mass Transfer,2007,50(1): 3638-3648. [19] 周静伟,杨兴贤,耿丽萍,等. 非稳态冲击射流强化传热试验研究[J]. 机械工程学报,2010,46(6): 144-148. doi: 10.3901/JME.2010.06.144ZHOU Jingwei,YANG Xingxian,GENG Liping,et al. Experimental investigation on heat transfer augmentation with unsteady impinging jet[J]. Journal of Mechanical Engineering,2010,46(6): 144-148. (in Chinese) doi: 10.3901/JME.2010.06.144 [20] PERSOONS T,BALGAZINA K,BROWN K,et al. Scaling of convective heat transfer enhancement due to flow pulsation in an axisymmetric impinging jet[J]. Journal of Heat Transfer,2013,135(11): 803-816. [21] LÜ Y W,ZHANG J Z,SHAN Y,et al. The experimental investigation of impinging heat transfer of pulsation jet on the flat plate[J]. ASME Journal of Heat Transfer,2018,140(1): 1-11. [22] 唐婵,张靖周,谭晓茗,等. 带集气腔的脉冲射流冲击换热实验和数值研究[J]. 航空动力学报,2019,34(6): 1334-1343. doi: 10.13224/j.cnki.jasp.2019.06.016TANG Chan,ZHANG Jingzhou,TAN Xiaoming,et al. Experimental and numerical study on pulsed-jet impingement heat transfer with an additional collection chamber[J]. Journal of Aerospace Power,2019,34(6): 1334-1343. (in Chinese) doi: 10.13224/j.cnki.jasp.2019.06.016 [23] 吕元伟,张靖周,王博滟,等. 冠齿喷嘴射流冲击平直靶面对流换热实验[J]. 航空学报,2018,39(3): 94-100.LÜ Yuanwei,ZHANG Jingzhou,WANG Boyan,et al. Experimental of chevron nozzle jet impingement heat transfer on flat targeting surface[J]. Acta Aeronautica et Astronautica Sinica,2018,39(3): 94-100. (in Chinese) [24] XIA H,TUCKER P G,EASTWOOD S. Large-eddy simulations of chevron jet flows with noise predictions[J]. International Journal of Heat and Fluid Flow,2009,30(1): 1067-1079.