封闭腔室高速旋转圆盘空气流场仿真与实验研究

发布时间：2018-02-01 19:51

本文关键词： 高速旋转圆盘空气流场气固耦合计算机硬盘　出处：《吉林大学》2017年硕士论文　论文类型：学位论文

【摘要】：封闭腔室旋转圆盘作为典型的机械结构,被广泛应用于工业领域,如机械式硬盘、圆锯片、压缩机圆盘等。为了提高圆盘工作稳定性,对高速旋转圆盘封闭腔室内流体和圆盘的耦合特性研究,具有重要的实际意义和应用价值。本文通过理论与实验相结合的方法,研究气固耦合下刚性和柔性旋转圆盘封闭腔室流体的特性和规律,分析了不同转速、倾角、厚度、轴向位置和轴径尺寸的旋转圆盘对腔室内圆盘和流体运动的影响,并设计搭建了专门的试验台,实验验证理论仿真结果的正确性。首先,根据流体力学理论,对封闭腔室内刚性旋转圆盘的流场进行理论分析。基于服务器硬盘的内部腔室结构,建立空气腔室三维模型并划分网格。借助Fluent软件,依照流体真实流动状态设置边界条件,并进行仿真计算。对计算结果进行后处理,研究不同转速下刚性圆盘腔室内速度场、压强场和涡量场的变化规律。分析表明:腔室内速度和压强整体均随圆盘转速升高而增大;指定转速下,速度和压强沿圆盘半径向外逐渐增大;高转速时,磁头对腔室内流场影响明显。其次,进一步研究封闭腔室内柔性旋转圆盘的气固耦合特性。首先建立了不同转速、倾角、厚度、轴向位置和轴径尺寸的柔性旋转圆盘和腔室简化模型,运用COMSOL软件对气体和圆盘进行双向气固耦合仿真分析。最后对结果进行后处理,得出气固耦合作用下圆盘的应力应变云图和气体的速度压强云图。探究不同状态下旋转圆盘位移和应力的变化,及其对腔室内流体速度和压强分布造成的影响。分析表明:圆盘和流体间的耦合作用,使倾斜圆盘向垂直于电机轴圆盘变形;圆盘位置升高度,腔室内压强减小,但速度大小变化不明显;轴径增大圆盘应力和压强减小,流体流速增大;当圆盘增厚时,应力增大,位移减小。最后,设计实验方案,搭建试验台软件和硬件,开展封闭腔室旋转圆盘实验研究。利用有机玻璃板构造密封腔室,并在上盖半径方向上等距布置三个压强传感器,外缘布置转速表。圆盘在不同转速和腔室轴向位置条件下,采集圆盘转速和腔室内的压强。对压强数据进行处理,得出腔室内流体压强随圆盘转速和位置变化的特性。针对实验平台构建模型进行气固耦合仿真,提取腔室内沿半径方向三点流体压强值,与实验结果相对照,验证了柔性圆盘气固耦合仿真结果的正确性。本文以理论仿真与实验验证相结合的方法,研究了刚性旋转圆盘封闭腔室内流场的变化特征,和封闭腔室内柔性旋转圆盘与空气的耦合特性,具有一定研究价值和实际意义。
[Abstract]:As a typical mechanical structure, closed chamber rotary disk is widely used in industrial fields, such as mechanical hard disk, circular saw blade, compressor disc, etc. In order to improve the stability of disk operation. It is of great practical significance and practical value to study the coupling characteristics of fluid and disk in the chamber of high speed rotating disk. The method of combining theory with experiment is adopted in this paper. The characteristics and rules of fluid in rigid and flexible rotating disk chamber under gas-solid coupling are studied, and different rotational speeds, inclination angles and thickness are analyzed. The influence of the axial position and the diameter of the rotating disc on the disk and fluid motion in the chamber was studied and a special test rig was designed to verify the correctness of the theoretical simulation results. Firstly, according to the hydrodynamics theory. The flow field of rigid rotating disk in closed chamber is analyzed theoretically. Based on the structure of the inner chamber of the server hard disk, the three-dimensional model of the air chamber is established and meshed. Fluent software is used. The boundary conditions are set according to the real flow state of the fluid, and the simulation results are calculated. The velocity field in the rigid disk chamber under different rotational speeds is studied by post-processing the calculated results. The variation of pressure field and vorticity field. The analysis shows that the velocity and pressure of the chamber increase with the increase of the rotating speed of the disk. The velocity and pressure increase gradually along the radius of the disk at specified rotational speed. At high speed, the magnetic head has an obvious effect on the flow field in the cavity. Secondly, the gas-solid coupling characteristics of the flexible rotating disk in the closed chamber are further studied. Firstly, different rotational speeds, inclination angles and thickness are established. The simplified model of flexible rotating disk and chamber with axial position and axial diameter size is used to simulate and analyze bidirectional gas-solid coupling of gas and disk by using COMSOL software. Finally, the results are processed after processing. The stress-strain cloud diagram of the disk and the velocity pressure cloud diagram of the gas are obtained under the action of gas-solid coupling. The changes of displacement and stress of the rotating disc under different states are investigated. The analysis shows that the coupling action between the disk and the fluid causes the inclined disk to be perpendicular to the electric shaft disk. The pressure of the chamber decreases with the elevation of the disc position, but the change of the velocity is not obvious. The axial diameter increases the disc stress and pressure decreases, and the fluid velocity increases. When the disk is thickened, the stress increases and the displacement decreases. Finally, the experimental scheme is designed, the software and hardware of the test bed are built, the closed chamber rotating disk experimental research is carried out, and the sealed chamber is constructed by using the plexiglass plate. At the same time, three pressure sensors are arranged in the radius direction of the upper cover, and the tachometer is arranged on the outer edge. The disk is arranged under the conditions of different rotational speed and axial position of the chamber. The pressure data were processed to get the characteristics of the fluid pressure changing with the rotating speed and position of the disc. The gas-solid coupling simulation was carried out on the experimental platform. Compared with the experimental results, the correctness of gas-solid coupling simulation results of flexible disk is verified by extracting the pressure values of three-point fluid along the radius of the chamber. The method of combining theoretical simulation with experimental verification is used in this paper. The characteristics of the flow field in the closed chamber of rigid rotating disk and the coupling characteristics between the flexible rotating disc and the air in the closed chamber are studied, which is of certain value and practical significance.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH113

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