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Experimental Investigation of Instabilizing Mechanism of Super High Pressure Pump Induced by Noncontacting Seal

非接触密封致超高压泵失稳机理的实验研究

基本信息

批准号：
61460113
负责人：
IWATSUBO Takuzo
金额：
$ 3.84万
依托单位：
Kobe University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1986
资助国家：
日本
起止时间：
1986 至 1987
项目状态：
已结题

项目摘要

In the pump design, clearance of noncontacting seal is decreased in order to prevent the leakage flow in a high presure pump, but unstable vibration may occure by decreasing the clearance. In this study fluid force induced by the noncontacting seal and also the vibration of rotor induced by it's fluid force are analyzed.First an experimental apparatus to measure the fluid force induced by the noncontacting seal is built and instability mechanism of the fluid force are analyzed by measuring the axial and circunferencial flow components. That is, flow distribution and pressure distribution in the seal are measured for changing whirling speed and spinning speed of the rotor and the fluid force is obtained from the above measured values.Next the instability force induced by the clearance flow in the seal is theoretically obtained and nathematical model for design of seal is formulated, which is qualitatively coincident with the experimental results.It is concluded from the above analysis; (1) Fluid force increases as the whirl amplitude increases, but it decreases as the seal clearance increases. (2) Inlet swirl velocity effects very much on the stability of rotor system. Positive swirl velocity acts unstable to the rotor and negative one does stable. (3) Tangential fluid force increases as the spinning speed of the shaft increases and it effects unstable to the rotor system. (4) Axial flow velocity effect stable to the rotor system. This effect is represented as the fluid force of the radial direction. (5) Coeffecients of stiffness term K_<xx>,K_<xy> are effected much for the inlet swirl velocity compared with coeffecients of mass and damping terms. (6) The experimental results and the theoretical results obtained by infinite width approximation theory coincide qualitatively but these results have discrepancies in quantity.

在高压泵的设计中，为了防止泄漏流，减小了非接触式密封的间隙，但减小间隙会产生不稳定的振动。本文分析了非接触式密封所产生的流体力以及由流体力引起的转子振动。首先建立了非接触式密封的流体力测量实验装置，并通过对轴向和环向流动分量的测量，分析了流体力的失稳机理。即通过改变转子的旋转速度和旋转速度来测量密封内的流量分布和压力分布，并由上述测量值得到流体力。其次，从理论上得到了间隙流在密封中引起的失稳力，并建立了密封设计的数学模型，与实验结果定性吻合。从以上分析可以得出结论：(1)流体力随旋流幅值的增大而增大，但随密封间隙的增大而减小。(2)进口旋流速度对转子系统的稳定性影响很大。正旋流速度对转子不稳定，负旋流速度对转子稳定。(3)切向流体力随着轴转速的增大而增大，对转子系统产生不稳定的影响。(4)轴流速度对转子系统的影响稳定。这种效应表示为径向的流体力。(5)与质量系数和阻尼系数相比，刚度系数K_<xx>、K_<xy>对进口旋流速度的影响更大。(6)用无限宽近似理论得到的实验结果与理论结果在质上一致，但在量上存在差异。