Study on Sediment Transport Process on Permeable Bed

透水床泥沙运移过程研究

• 批准号: 61460167
• 负责人: NAKAGAWA Hiroji
• 金额: $ 2.3万
• 依托单位: Kyoto University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1986
• 资助国家: 日本
• 起止时间: 1986 至 1987
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-61460167/
• 关键词: rough permeable bed; seepage flow; transpiration; sediment transport process; pick-up rate; 対数二乗則; 護床工

In order to predict the alluvial phenomenon in the natural rivers with the permeable boundaries and seepage flow, it is necessary to establish a model to describe non-equilibrium sediment transport process on a permeable bed, of which constituent elements are sediment pick-up rate and step length. In this study, it is intended to propose a reasonable formula to estimate the pick-up rate of sand particles on a permeable bed with steady transpiration velocity and to verify the derived formula experimentally. As for the step length, firstly the experimental research is intended, and based on its information, a reasonable way of estimating the step length is proposed.Incipient motion and transport of a sand particle affected by transpiration velocity has been theoretically analyzed. Meanwhile, a devised experiment has been carried out in laboratory flume to obtain the experimental data in good accuracy, by making use of a video film analyzing system. The obtained results of this study will … More be available for analyses of various kinds of fluvial process in rivers.Next, in order to make the above mentioned model exact the flow structure has been examined. When the seepage flow in the highly permeable porous medium is accompanied with the flow over it, the interaction between surface flow and seepage flow cannot be neglected. In case of high permeability, Darcy law for seepage flow is not necessarily applicable because of the predominance of non-linearity term. This non-linearity makes the propagation of the pressure fluctuation inherent to the free surface flow into the inside of the porous medium and the subsequent fluctuation of seepage flow velocity anisotropic, and the subsequent appearance of apparent Reynolds stress plays a role of appreciable momentum exchange. Namely seepage flow is affected by the drag of the faster free usrface flow. In this part of this study. a physical modelling of this mechanism is formulated to evaluate the induced seepage velocity, and the effect on the sediment transport process is examined. The theoretical results are verified by flume experiments. Less

为了预测具有透水边界和渗流的天然河流中的冲淤现象，需要建立一个描述透水河床上非平衡输沙过程的模型，模型的组成元素是泥沙的挟沙率和步长。本文提出了一个合理的公式来估算具有稳定蒸腾速度的透水床面上沙粒的拾取率，并通过实验对公式进行了验证。对于步距，首先进行了实验研究，并在此基础上提出了合理的步距估算方法，从理论上分析了蒸腾速度对沙粒起动和输移的影响。同时，在实验室水槽中进行了设计性试验，利用视频分析系统获得了较准确的试验数据。这项研究的结果将 ...更多信息 为了使上述模型更精确，本文还对水流结构进行了分析。当高渗透性多孔介质中的渗流同时伴随有过流时，表面流与渗流的相互作用是不可忽略的。在高渗透率情况下，非线性项占优势，达西渗流定律不一定适用。这种非线性使得自由表面流动固有的压力波动传播到多孔介质内部，以及随后的渗透流速波动各向异性，并且随后出现的表观雷诺应力起到了明显的动量交换作用。即渗流受速度较快的自由表面流的阻力影响。在本研究的这一部分。这一机制的物理模型制定，以评估诱导的渗透速度，并对泥沙输运过程的影响进行了检查。水槽试验验证了理论分析结果。少

项目成果

中川博次: 第31回水理講演会論文集. 359-364 (1987)

Hirotsugu Nakakawa：第 31 届水利会议记录，359-364 (1987)。

Tetsuro Tsujimoto: Memoirs of the Faculty of Technology, Kanazawa University. 19. 21-32 (1986)

Tetsuro Tsujimoto：金泽大学技术学院回忆录。

Hiroji Nakagawa: "Flow Structure over Rough Permeable Bed as a Preliminary Study on Gravel Bed Load Transport" Proc. 32nd Japanese Conference on Hydraulics, JSCE (in Japanese).535-540 (1988)

Hiroji Nakakawa：“粗糙渗透层上的流动结构作为砾石层荷载传输的初步研究”Proc。

Hiroji Nakagawa: "Enlargement of the Cavity Due to Sweeping of Sands beneath Bed Protection as a Cause of Weir Disaters" Proc. 31st Japanese Conference on Hydraulics, JSCE (in Japanese).359-364 (1987)

Hiroji Nakakawa：“由于在床层保护下清扫沙子而造成的空腔扩大，是堰灾的原因”。

Hiroji Nakagawa: "Effect of Suction or Injection thriugh Bottom of a Stream on Bed Load Transport Process" Proc. International Symposium on Flluvial Hydraulics, Budapest, Hungary, 1988. (1988)

Hiroji Nakakawa：“通过流底部抽吸或注入对床层负载运输过程的影响”Proc。