节流槽型阀口噪声特性试验研究

运用压力分布测量、噪声测试、流场仿真及理论分析对典型节流槽的噪声特性进行了研究。压力分布测量结果与流场仿真吻合良好，在大量试验的基础上揭示了节流槽的噪声特性规律。研究发现节流槽型阀口噪声与流场压力分布特征密切关联，噪声主要取决于节流槽形状、流动方向及背压大小，渐扩形节流槽容易出现啸叫，而具有等截面流道的节流槽噪声较低。此项研究对于具有节流槽液压元件的噪声控制具有重要的理论价值和工程实用价值。

EXPERIMENTAL STUDY ON NOISE CHARACTERISTICS OF GROOVE-TPYE ORIFICES

The mechanism of the noise differences related to the groove-type orifices in spool valve is investigated. The experiment approaches of the pressure distribution measurement and noise measurement as well as the numerical approach of CFD analysis are used to study the noise characteristics of the groove-type orifices. The measurements of the pressure distribution are achieved by a unique designed valve unit with the sleeve shift. The study shows the noise level of groove-type orifice is mainly determined by the geometry of the groove, the direction of oil flow in grooves and the value of backpressure in the valve return chamber. Both the experimental and the numerical results of pressure distributions reveal that the noise of the groove-type orifices has close relationship with the pattern of the pressure distributions in the groove. In converging flow direction of the groove, the groove with increasing cross-section area tend to cause quite higher noise at a certain value of the backpressure, while the groove with constant cross-section can restrain the air-release inside the groove passage and shows much quiet. In diverging flow direction, the noise characteristics of the grooves are almost same, and the noise level is considerably low.