运动导叶在不同长度时的旋流特性研究

发布时间：2018-04-14 15:06

本文选题：旋流器 + 螺旋流　；参考：《太原理工大学》2014年硕士论文

【摘要】：为寻求一种平稳的管道水力输送方式,针对传统的型料管道水力输送进行了改进,以旋流器作为输送物料的密闭容器,本论文是基于国家自然科学基金项目“管道缝隙螺旋流水力特性研究”(51109115)和国家自然科学基金项目“管道列车水力输送能耗研究”(51179116),采用理论分析与模型试验相结合的研究方法,分析了不同导叶长度的旋流器在运动时产生的螺旋流旋流特性。结果表明： 1.相同雷诺数下不同导叶长度的旋流器,在运动的过程中,随着导叶长度的增加,管内水流的压强分布表现出先减小后增大的趋势,其中导叶长度为l=0.5L的压强值最小；随着导叶长度的增加,轴向速度表现为先减小后增大再减小的趋势,周向速度表现为先增大后减小的趋势。而且当导叶的长度l=0.75L时,测试断面的轴向流速的平均值最大,当导叶长度l=0.5L时,测试断面的周向速度平均值和径向速度的平均值均最大。 2.对于同一型号的旋流器,雷诺数Re越大,测试断面水流的压力就越大,轴向速度也越大,而且流速梯度分布也越密集；周向速度随雷诺数Re的增长幅度要大于径向速度随雷诺数Re的增长幅度。 3.在同种工况且旋流器的导叶高度和长度相同的情况下,测试断面的压强随导叶的旋转角度的增大而增大；轴向速度平均值也随导叶的旋转角度的增大而增大；当旋流器位于测试断面上游时,随着旋流器导叶旋转角度的增加,管道水流在测试断面处其周向速度越大；而当旋流器位于测试断面下游时,则得到相反的结果；导叶的旋转角度越大,测试断面水流的径向速度的绝对值越小。 4.在测试断面的水平中心测孔上水流的轴向速度整体上表现为偏心的、非对称的抛物线型分布；而且雷诺数越大,典型测孔的各测点的轴向速度随之增大,而且增大的幅度也很大。当旋流器位于测试断面上游时,旋转角度大的旋流器其测试断面水平位置中心测孔的轴向速度平均值较大；而当旋流器位于测试断面的下游时,则相反。 5.在设计工况为Re=0.8x105的条件下,旋流器型号为0=5°、h=15mm、l=L时,其在整个管道系统运行过程中所消耗的单位能耗最小。而在设计工况为Re=1.1×105的条件下,则是旋流器型号为0=5°、h=15mm、l=0.75L时,其消耗的单位能耗相对较小。本论文的研究成果对动边界螺旋流理论和旋流器在实际生产中的应用提供一定的理论依据。
[Abstract]:In order to find a stable pipeline hydraulic transportation mode, the traditional type material pipeline hydraulic transportation was improved, and the hydrocyclone was used as the closed vessel for conveying material.This paper is based on the project of National Natural Science Foundation of China "study on the force characteristics of helical income in pipeline gap" and the project of National Natural Science Foundation of China "study on Energy consumption of Pipeline Train hydraulic Transportation" (51179116), using theoretical analysis and model test phase.Combined research methods,The helical flow characteristics of the hydrocyclone with different guide vane lengths are analyzed.The results show that:1.With the increase of guide vane length, the pressure distribution of water flow in the hydrocyclone with the same Reynolds number decreases first and then increases with the increase of the guide vane length, and the pressure of the guide vane length is the smallest when the length of the guide vane is 0.5 L;With the increase of the length of the guide blade, the axial velocity decreases first and then increases and then decreases, and the circumferential velocity increases first and then decreases.When the length of the guide blade is 0.75 L, the average axial velocity of the test section is the largest, and when the length of the guide blade is 0.5 L, the average value of the circumferential velocity and the radial velocity of the test section are the largest.2.For the same type of hydrocyclone, the larger the Reynolds number re, the greater the pressure of water flow, the greater the axial velocity and the denser the velocity gradient distribution.The increase of circumferential velocity with Reynolds number re is larger than that of radial velocity with Reynolds number re.3.Under the same condition that the guide vane height and length of the same type cyclone are the same, the pressure of the test section increases with the increase of the rotating angle of the guide vane, and the average axial velocity increases with the increase of the rotating angle of the guide vane.When the hydrocyclone is located upstream of the test section, the circumferential velocity of the pipe flow increases with the increase of the rotating angle of the guide vane of the hydrocyclone, but the contrary results are obtained when the hydrocyclone is located downstream of the test section.The larger the rotating angle of the guide blade is, the smaller the absolute value of the radial velocity of the measured cross section is.4.In the horizontal center of the test section, the axial velocity of the flow is eccentric and asymmetrical parabola, and the larger the Reynolds number is, the more the axial velocity of the measured points increases.And the increase is also very large.When the hydrocyclone is located upstream of the test section, the axial velocity average of the central hole in the horizontal position of the test section is higher than that of the hydrocyclone with high rotation angle, but the opposite is true when the hydrocyclone is located downstream of the test section.5.When the design condition is Re=0.8x105, the unit energy consumption of the hydrocyclone is minimum when the type of cyclone is 0 ~ 5 掳/ h ~ (15) mm / L, and the unit energy consumption is minimum during the operation of the whole pipeline system.However, when the design condition is Re=1.1 脳 10 ~ 5, the unit energy consumption is relatively small when the hydrocyclone model is 0 ~ 5 掳/ h ~ (-1) 15mm / L.The research results of this paper provide some theoretical basis for the theory of moving boundary spiral flow and the application of hydrocyclone in practical production.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U171;TV134

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