Research On The Mechanical Behavior Of Temperature Control Curtain In Deep Reservoir

With the rising tide of large reservoir construction at home,hydroelectric power generation creates enormous economic and social benefits while it changes the environmental factors of existing river and downstream river reaches.Deep reservoirs can bring water temperature stratification which may further lead to water quality and ecological environment stratification,and eventual ecological environmental deterioration and social contradiction.This paper made thoroughly research on the temperature control curtain which can improve water temperature.The main contents and results are as follows:(1)Research on the material used in temperature control curtain in deep reservoir.On the basis of market research and initial analysis of commonly used rope materials,such as nylon,high performance polyethylene(Dyneema),polyester and polypropylene,this paper synthetically compared and analyzed physical parameters of these materials,including tensile strength,ductility and density.After the analysis,an appropriate framework material for temperature control curtain was selected.The paper also analyzed and compared physical parameters of different curtain materials between PP Series high toughness polypropylene woven geotextile and PET Series high toughness polyester reinforcement geotextile.(2)Experience and Analysis of Mechanical Properties of the material.The tensile experiments have been conducted for the rope and curtain used as the chief materials of temperature control curtain in deep reservoir.The material of rope was high performance polyethylene(Dyneema)and curtain was high toughness polypropylene woven geotextile respectively.In order to acquire mechanical parameters(e.g.,elastic modulus and maximum breakage strain)and stress-strain curve of materials under different conditions,tensile experiments with different diameter Dyneema rope,various kinds materials and stretching methods of curtain were done.The results of experiments provide referential options for material-selecting in temperature control curtain construction and three-dimensional numerical simulations basic data for later chapters.(3)Three-dimensional fluid-structure interaction numerical simulations study on temperature control curtain.Based on three-dimension finite element analysis software ANSYS,a temperature control curtain model was established by using Space Splice Chain Pole Discrete Element LINK10 and Plane Stress Element SHELL181.The model assumes that the contact surface between the rope and curtain is no slip.Form-finding analysis was realized by using small elastic modulus method.By using Workbench and CFX in ANSYS,a fluid-structure interaction numerical model was build and analyzed.The parameters of the model was set according to the measured data obtained in a deep reservoir.Chief materials properties of temperature control curtain and the influence of mechanical behavior of curtain caused by flow characteristics were discussed.The results of this paper provide a technical support in design,construction,operation and maintenance of temperature control curtain,and help to popularize and apply the temperature control curtain to improve water temperature.