冰水两相流输水浮冰受力特性研究
发布时间：2018-11-11 12:56
【摘要】：冰水两相流输水过程中,输水流速对浮冰的运动影响很大。浮冰跟随水流漂浮的过程中受到竖直和水平两个方向力的作用。浮冰的翻转下潜与前缘效应和文丘里效应产生的压差有关,冰水相对流速、浮冰尺寸会影响前缘效应和文丘里效应。冰水之间产生相对流速与浮冰水平方向的受力有关,主要包括水流拖曳力和风应力。本文通过数学模型对浮冰的受力情况进行了模拟分析。相对流速较小时,浮冰厚度和宽度的变化对前缘效应和文丘里效应的影响不大；相对流速较大时,随着浮冰厚度的增加,前缘效应和文丘里效应逐渐增强,浮冰宽度的变化对前缘效应和文丘里效应会产生一定的影响,但是影响不大；浮冰尺寸不变时,冰块前缘效应和文丘里效应随着相对流速的增加而增加。本文通过对浮冰竖直方向的受力分析,得出了一定尺寸范围内浮冰的临界翻转相对流速,以及临界翻转相对流速与冰厚的关系。拖曳力系数与浮冰的尺寸、形状、相对流速、水的运动黏度、块体所在的空间位置、浮冰密度等因素有关；本文对水流拖曳力系数的影响因素进行了量纲分析,得出拖曳力系数是浮冰“长高比”的函数；对于在一定尺寸范围内的浮冰,本文通过数值模拟计算,给出了拖曳力系数与浮冰“长高比”的关系公式；考虑风对浮冰的水平作用力,浮冰在风与水流的共同作用下达到平衡状态,本文给出了平衡状态条件下,浮冰速度与水流流速的关系公式。
[Abstract]:In the course of ice-water two-phase flow, the velocity of water conveyance has a great influence on the motion of floating ice. Ice floats are subjected to vertical and horizontal forces in the course of following the current. The overturn of floating ice is related to the pressure difference caused by the leading effect and Venturi effect. The relative velocity of ice water and the size of floating ice will affect the front effect and Venturi effect. The relative velocity between ice and water is related to the horizontal force of the ice floe, including the drag force and wind stress. In this paper, the force of floating ice is simulated and analyzed by mathematical model. When the relative velocity is small, the change of ice thickness and width has little effect on the leading edge effect and Venturi effect. With the increase of ice thickness, the leading edge effect and Venturi effect gradually increase, and the change of ice width will have a certain effect on the leading edge effect and Venturi effect, but the effect is not significant. When the ice size is constant, the ice front effect and Venturi effect increase with the increase of relative velocity. In this paper, the critical turnover relative velocity and the relationship between the critical turnover relative velocity and the ice thickness are obtained through the analysis of the vertical force of the floating ice. The drag force coefficient is related to the size, shape, relative velocity, the viscosity of water movement, the space location of the block, the density of the ice, and so on. In this paper, the factors influencing the drag force coefficient of water flow are analyzed, and it is concluded that the drag force coefficient is a function of the ratio of length to height of floating ice. In this paper, the relationship between drag force coefficient and the ratio of length to height of floating ice is given by numerical simulation. Considering the horizontal force of wind on ice floe, the ice reaches equilibrium state under the action of wind and current. In this paper, the formula of the relationship between velocity of floating ice and flow velocity is given under the condition of equilibrium.
【学位授予单位】：中国水利水电科学研究院
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TV133
本文编号：2324898
[Abstract]:In the course of ice-water two-phase flow, the velocity of water conveyance has a great influence on the motion of floating ice. Ice floats are subjected to vertical and horizontal forces in the course of following the current. The overturn of floating ice is related to the pressure difference caused by the leading effect and Venturi effect. The relative velocity of ice water and the size of floating ice will affect the front effect and Venturi effect. The relative velocity between ice and water is related to the horizontal force of the ice floe, including the drag force and wind stress. In this paper, the force of floating ice is simulated and analyzed by mathematical model. When the relative velocity is small, the change of ice thickness and width has little effect on the leading edge effect and Venturi effect. With the increase of ice thickness, the leading edge effect and Venturi effect gradually increase, and the change of ice width will have a certain effect on the leading edge effect and Venturi effect, but the effect is not significant. When the ice size is constant, the ice front effect and Venturi effect increase with the increase of relative velocity. In this paper, the critical turnover relative velocity and the relationship between the critical turnover relative velocity and the ice thickness are obtained through the analysis of the vertical force of the floating ice. The drag force coefficient is related to the size, shape, relative velocity, the viscosity of water movement, the space location of the block, the density of the ice, and so on. In this paper, the factors influencing the drag force coefficient of water flow are analyzed, and it is concluded that the drag force coefficient is a function of the ratio of length to height of floating ice. In this paper, the relationship between drag force coefficient and the ratio of length to height of floating ice is given by numerical simulation. Considering the horizontal force of wind on ice floe, the ice reaches equilibrium state under the action of wind and current. In this paper, the formula of the relationship between velocity of floating ice and flow velocity is given under the condition of equilibrium.
【学位授予单位】：中国水利水电科学研究院
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TV133
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，本文编号：2324898
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