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一、气动换向阀排气噪声的特征许多资料表明:在一般情况下,表压为0.5MPa 左右的压缩空气通过气缸等气动执行机构后,经换向阀直接排入大气时的剩余压力约在0.3～0.35MPa 左右。此时的压力比超过了临界压力比(1.893∶1)。因此,换向阀排气口的气流速度达到了超音速。超音速气流进入大气时产生的振动波会使相对静止的空气瞬间成为高速混合气体,引起严重的紊流,产生噪声。通过频谱分析图可知,这种噪声在1000～8000Hz 的高频声段
First, the pneumatic valve exhaust noise characteristics Many data show that: under normal circumstances, the gauge pressure of about 0.5MPa compressed air through the cylinder and other pneumatic actuators, the direct valve into the atmosphere by the residual pressure of about In about 0.3 ~ 0.35MPa. The pressure ratio at this time exceeded the critical pressure ratio (1.893: 1). As a result, the air flow velocity at the outlet of the reversing valve reaches supersonic speed. Vibration waves generated when the supersonic airflow enters the atmosphere cause the relatively stationary air to instantly become a high-speed mixed gas, causing severe turbulence and noise. Through the spectrum analysis shows that this noise in the high-frequency segment of 1000 ~ 8000Hz