Modelling the transport of fine suspended sediments

The study of fine sediment transport is complicated because it consists of many separate processes such as flocculation if the sediment is cohesive, settling and mixing, deposition, re-suspension and consolidation, etc. In order to model the transport process accurately, all the above-mentioned indi...

وصف كامل

محفوظ في:
التفاصيل البيبلوغرافية
المؤلف الرئيسي: Nguyen, Hoang Ha
مؤلفون آخرون: Chua Hock Chye, Lloyd
التنسيق: Theses and Dissertations
اللغة:English
منشور في: 2012
الموضوعات:
الوصول للمادة أونلاين:https://hdl.handle.net/10356/50489
الوسوم: إضافة وسم
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الوصف
الملخص:The study of fine sediment transport is complicated because it consists of many separate processes such as flocculation if the sediment is cohesive, settling and mixing, deposition, re-suspension and consolidation, etc. In order to model the transport process accurately, all the above-mentioned individual processes and the hydrodynamic characteristics of the flow field need to be correctly modeled, simultaneously. Many studies on the sediment transport process have been conducted in the past; however, gaps exist in our knowledge on this topic and much scope for improvements exists. The present study focuses on some of the fundamental behaviour of sediments in the aquatic environment. These include floc density, dynamic viscosity, and effects of turbulence and sediment concentration on flocculation and settling velocity of (floc) particles. A physically-based parametric approach is developed to improve the existing models; turbulent Reynolds number ( Ret ≡ k2 / εv , where k and ε are the turbulent kinetic energy and its dissipation rate, respectively), which reflects the turbulence level, is used to estimate the strength of flocs and effects of turbulence on the flocculation and settling velocity.