| 摘要: |
| 为了研究粗糙地形对内波共振生成的影响，本文在实验中采用粒子图像测速法（PIV）对内波速度场进行测量。实验中设置了两种不同尺度的粗糙地形，其中一种地形的粗糙尺度大于黏性边界层厚度（δ），另一种地形的粗糙尺度小于δ。结果表明两种粗糙地形都使共振内波的能量减弱,粗糙地形一侧生成的内波强度约为光滑地形一侧生成内波强度的40%。当粗糙地形的尺度大于δ时，在粗糙地形一侧除了共振内波以外还有明显的内波射线生成，粗糙地形上的每一个凸形间断点都成为了一个新的内波源点，每条内波射线的强度约为共振内波强度的1/10，由新源点生成的内波射线相位基本一致，落后于正压潮3π/5个相位。当粗糙地形的尺度小于δ时，粗糙地形一侧仅有共振内波生成，共振内波的相位与正压潮相位十分接近。 |
| 关键词: 内波实验 粗糙地形 PIV技术 振荡地形 |
| DOI：10.11693/hyhz20160100006 |
| 分类号: |
| 基金项目:国家自然科学基金项目，41476001号，41276008号。 |
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| LABORATORY STUDY ON INTERNAL WAVE GENERATION IN ROUGH TOPOGRAPHY |
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WANG Jin-Hu, CHEN Xu, XU Yang
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Key Laboratory of Physical Oceanography, Ocean University of China, Qingdao 266100, China
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| Abstract: |
| To simulate the effect of topography roughness on generation of resonant internal waves, we conducted a laboratory experiment and the velocity field of internal waves was measured with particle image velocimetry (PIV) technology. Two different amplitudes of roughness were applied, of which one was greater than thickness of viscous boundary layer (δ), and the other one, smaller. Results show that the strength of resonant internal waves was weakened in both topography conditions. The strength of internal waves generated from rough topography was 40% of that from smooth one. When amplitude of roughness was greater than δ; additional to resonant internal waves, obvious internal wave rays emanated from the rough side of topography. Each convex point on rough topography became a new generation point of internal wave. The amplitude of each new internal wave ray was 1/10 of that of the resonant internal wave. The phase of theses internal wave rays was identical, which was nearly 3π/5 behind the forcing barotropic current. When amplitude of roughness was smaller than δ, only resonant internal waves were generated from the rough side. The phase of the resonant internal wave almost identical to the barotropic current. |
| Key words: internal wave experiment rough topography particle image velocimetry (PIV) oscillating topography |
