Experimental Study on Resuspension, Transportation and Deposition Processes of Mud Particles on the bed of Estuaries

河口底泥泥颗粒再悬浮、输送和沉积过程的实验研究

• 批准号: 06660307
• 负责人: HIRAMATSU Kazuaki
• 金额: $ 1.28万
• 依托单位: Kyushu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06660307/
• 关键词: Mud Particle; Estuary; Resuspension; Convective Dispersion; Deposition; Turbidity; Field Survey; Numerical Simulation

Resuspension, transportation and deposition processes of mud particles on the bed of polluted estuaries yield two serious problems in hydrosphere. One is the turbid water as a result of the resuspension and transportation of mud particles themselves, and the other is the supply of nutrients and pollutant matters to hydrosphere. In this study, resuspension, transportation and deposition mechanisms of mud particles were investigated experimentally. The main purpose of this study was reasonably to estimate the critical shear stress of mud and the turbulent diffusion coefficient and trubulent fall velocity of suspended mud particles.Using visco-meters and an annular flume, the flow curve property and critical shear stress of mud were investigated experimentally. It was very interesting and important result that the critical shear stress of mud was determined approximately by its yield value.Convective dispersion mechanism of suspended mud particles in open channel shear flow was studied experimentally. The concentration of suspended solids were measured by the method of video-image data processing, and a laser doppler velocimetry was used in flow velocity measurement. It was found that the turbulent diffusion coefficient and fall velocity of suspended mud particles were closely related to the total energy of the low frequency components in vertical velocity fluctuation.Using the results obtained from the experimental studies, numerical simulations were executed to regenerate the tidal current velocity and turbidity of the Ariake sea. The fluid flow equation and mass transfer equation were formulated in forms that allowed the establishment of finite difference approximation of the two-dimensional single-layr model, and the numerical model was successfully coded.

泥沙颗粒在污染河口河床上的再悬浮、输移和沉积过程在水圈中产生两个严重的问题。一是泥沙颗粒本身的再悬浮和输送造成的水体浑浊，二是泥沙颗粒向水圈输送营养物质和污染物质。本研究主要针对泥浆颗粒的再悬浮、输运及沉积机理进行了实验研究。为了合理估算泥浆的临界切应力、悬浮泥浆颗粒的紊动扩散系数和紊动下落速度，采用粘度计和环形水槽对泥浆的流动曲线特性和临界切应力进行了实验研究。泥浆的临界剪切应力由其屈服值近似确定是一个非常有趣和重要的结果。悬浮物浓度的测量采用视频图像数据处理方法，流速测量采用激光多普勒测速仪。结果表明，悬浮泥沙颗粒的紊动扩散系数和下落速度与垂向速度脉动低频分量的总能量密切相关，利用实验结果，对有明海的潮流速度和浊度进行了数值模拟。建立了二维单层模型的有限差分近似形式的流体流动方程和传质方程，并成功地编制了数值模型。

项目成果

Masaaki KONDO: "Experimental Study on Erosion Process of Cohesive Bottom Materials by Tidal Current" Transactions of the Japanese Society of Irrigation, Drainage and Reclamation Engineering. 182 (In Press). (1996)

Masaaki KONDO：“潮汐流对粘性底部材料侵蚀过程的实验研究”日本灌溉、排水和填海工程学会会刊。

近藤 雅秋: "潮流による底泥の巻き上げ特性に関する研究" 農業土木学会論文集. 182(印刷中). (1996)

Masaaki Kondo：“潮汐流提升污泥特性的研究”，日本农业和土木工程师学会学报 182（出版中）。

平松 和昭: "濁り環境の解析手法" 農業土木学会誌. 62. 335-341 (1994)

Kazuaki Hiramatsu：“浑浊环境的分析方法”日本农业和土木工程师学会杂志 62. 335-341 (1994)。

Kazuaki HIRAMATSU: "Water Quality Analysis (7) -Numerical Analysis for Convective Dispersion of Suspended Solids-" Journal of the Japanese Society of Irrigation, Drainage and Reclamation Engineering. 62. 335-341 (1994)

Kazuaki HIRAMATSU：“水质分析（7）-悬浮固体对流分散的数值分析-”日本灌溉排水和垦殖工程学会杂志。

近藤雅秋: "潮流による底泥の巻き上げ特性に関する研究" 農業土木学会論文集. 182(印刷中). (1996)

Masaaki Kondo：“潮汐上升污泥特性的研究”，日本农业和土木工程师学会学报 182（出版中）。