Preliminary application of hot-film wall shear stress sensor under breaking waves
-
摘要: 破波区床面剪应力的正确认知对于揭示海岸泥沙输运以及地貌演变的机理具有重要意义。波浪破碎以后带来的紊动和涡旋会对床面剪应力产生显著的影响。采用MEMS柔性热膜式壁面剪应力传感器在波浪水槽中开展了破碎波作用下的床面剪应力测量应用测试。实验结果表明该壁面剪应力传感器可以应用于破碎波作用下的床面剪应力测量。在破波点之前可以根据近底流速辅助该传感器判断床面剪应力的方向。床面剪应力在波浪破碎之前变化较为平缓，在波浪破碎之后床面剪应力的波动和极值都会增大。斜坡上沿程最大床面剪应力均值的极值出现于卷破水舌入射点之后。Abstract: The knowledge of the bed shear stress under breaking waves is essential for understanding the sediment transport and beach morphology in the surf zone. The turbulence and vortexes generated by breaking waves have a significant effect on the bed shear stress. Application tests of the bed shear stress measurement under breaking waves by the MEMS flexible hot-film shear stress sensor are conducted in a wave flume. The experimental results show that the sensor can be applied to the measurement of the bed shear stress under breaking waves. Before the breaking point, the direction of the bed shear stress can be determined by the near-bed velocity. The change of the bed shear stress is gentle before wave breaking. The fluctuations and the peak value of the bed shear stress increase after wave breaking. The extreme value of the average maximum bed shear stress along the slope appears after the plunging point.
-
Key words:
- breaking waves /
- wall shear stress sensor /
- bed shear stress /
- plunging breaker
-
图 2 柔性热膜式壁面剪应力传感器工作原理
Figure 2. Operating principle of flexible hot-film shear stress sensor
图 5 安装于实验斜坡上的剪应力传感器
Figure 5. Wall shear stress sensor installed on the experimental slope
图 9 最大底部剪应力均值沿斜坡分布
Figure 9. Distribution of average maximum bed shear stress along the slope
表 1 破波实验的测量断面布置
Table 1. Measurement sections of bed shear stress
表 2 破波实验波浪要素
Table 2. Wave parameters for breaking wave experiment
-
[1] 邹志利.海岸动力学[M].第四版.北京:人民交通出版社, 2009.Zou Z L. Coastal hydrodynamics[M]. 4th ed. Bejing: China Communications Press, 2009. [2] Mirfenderesk H, Young I R. Direct measurements of the bottom friction factor beneath surface gravity waves[J]. Applied Ocean Research, 2003, 25(5): 269-287. doi: 10.1016/j.apor.2004.02.002 [3] Huo G, Wang Y G, Yin B S, et al. A new measure for direct measurement of the bed shear stress of wave boundary layer in wave flume[J]. Journal of Hydrodynamics, Ser B, 2007, 19(4): 517-524. doi: 10.1016/S1001-6058(07)60148-6 [4] Pujara N, Liu P L F. Direct measurements of local bed shear stress in the presence of pressure gradients[J]. Experiments in Fluids, 2014, 55(7): 1-13. doi: 10.1007/s00348-014-1767-8 [5] Pujara N, Liu P L F, Yeh H. The swash of solitary waves on a plane beach: flow evolution, bed shear stress and run-up[J]. Journal of Fluid Mechanics, 2015, 779: 556-597. doi: 10.1017/jfm.2015.435 [6] Arnskov M M, Fredsøe J, Sumer B M. Bed shear stress measurements over a smooth bed in three-dimensional wave-current motion[J]. Coastal Engineering, 1993, 20(3): 277-316. https://www.researchgate.net/profile/Tom_Baldock/publication/229027786_Direct_Bed_Shear_Stress_Measurements_in_Laboratory_Swash/links/00b7d518d634c47f8d000000.pdf [7] Sumer B M, Arnskov M M, Christiansen N, et al. Two-com-ponent hot-film probe for measurements of wall shear stress[J]. Experiments in Fluids, 1993, 15(6): 380-384. doi: 10.1007/BF00191776 [8] Jensen B L, Sumer B M, Fredsøe J. Turbulent oscillatory boundary layers at high Reynolds numbers[J]. Journal of Fluid Mechanics, 1989, 206: 265-297. doi: 10.1017/S0022112089002302 [9] Carstensen S, Sumer B M, Fredsøe J. Coherent structures in wave boundary layers. part 1. oscillatory motion[J]. Journal of Fluid Mechanics, 2010, 646: 169-206. doi: 10.1017/S0022112009992825 [10] Musumeci R E, Marletta V, Andò B, et al. Measurement of wave near-bed velocity and bottom shear stress by ferrofluids[J]. IEEE Transactions on Instrumentation and Measurement, 2015, 64(5): 1224-1231. doi: 10.1109/TIM.2014.2359521 [11] 梁婷, 夏云峰, 徐华, 等.波浪作用下床面切应力测量初探[J].水道港口, 2010, 31(5): 425-428. http://www.cnki.com.cn/Article/CJFDTOTAL-SDGK201005036.htmLiang T, Xia Y F, Xu H, et al. Preliminary study of bed shear stress measurement under wave action[J]. Journal of Waterway and Harbor, 2010, 31(5):425-428. http://www.cnki.com.cn/Article/CJFDTOTAL-SDGK201005036.htm [12] Xu H, Xia Y F, Ma B H, et al. Research on measurement of bed shear stress under wave-current interaction[J]. China Ocean Engineering, 2015, 29(4): 589-598. doi: 10.1007/s13344-015-0041-z [13] Boers M. Surf zone turbulence[D]. Netherlands: Delft University of Technology, 2005. [14] Deigaard R, Fredsøe J, Mikkelsen M B.Measurements of the bed shear stress in a surf zone[R]. Progress Report 73, Lyngby: Institute of Hydrodynamics and Hydraulic Engineering, Technical University of Denmark, 1991: 21-30. http://www.academia.edu/10624279/Beach_Stratigraphy [15] Yüksel Y, Çevik E Ö, Kapdanşli S. Bed shear stress distribution over beach profiles[J]. Journal of Coastal Research, 1998, 14(3): 1044-1053. [16] Sumer B M, Sen M B, Karagali I, et al. Flow and sediment transport induced by a plunging solitary wave[J]. Journal of Geophysical Research: Oceans, 2011, 116(C1): C01008. http://orbit.dtu.dk/files/5597782/2010JC006435.pdf [17] Sumer B M, Guner H, Hansen N M, et al. Laboratory observations of flow and sediment transport induced by plunging regular waves[J]. Journal of Geophysical Research: Oceans, 2013, 118(11): 6161-6182. doi: 10.1002/2013JC009324 [18] Schlichting H, Gersten K. Boundary-layer theory[M]. 9th ed. Berlin: Springer, 2016. [19] 马炳和, 王毅, 姜澄宇, 等.柔性热膜剪应力传感器水下测量温度修正[J].实验流体力学, 2014, 28(2): 39-44. doi: 10.11729/syltlx20140006Ma B H, Wang Y, Jiang C Y, et al. Temperature correction of flexible thermal shear stress sensor for underwater measurements[J]. Journal of Experiments in Fluid Mechanics, 2014, 28(2):39-44. doi: 10.11729/syltlx20140006 [20] Knight D W, Patel H S. Boundary shear in smooth rectangular ducts[J]. Journal of Hydraulic Engineering, 1985, 111(1): 29-47. doi: 10.1061/(ASCE)0733-9429(1985)111:1(29) [21] Koca K, Noss C, Anlanger C, et al. Performance of the Vectrino Profiler at the sediment-water interface[J]. Journal of Hydraulic Research, 2017: 1-9. (in press, doi: 10.1080/00221686.2016.1275049.) [22] Murai Y. Frictional drag reduction by bubble injection[J]. Experiments in Fluids, 2014, 55(7): 1773. doi: 10.1007/s00348-014-1773-x -
下载:
点击查看大图
图(9) / 表(2)
计量
- 文章访问数: 261
- HTML全文浏览量: 154
- PDF下载量: 7
- 被引次数: 0
