用LDV测量旋转流场的窗口效应分析

在应用激光多普勒测速仪测量旋转流场时，如果测量窗口随着旋转流着一起转动，就会产生窗口效应问题，实验研究和理论分析表明，如果测量体积与测量窗口之间的距离太小，由由窗口旋转速度引起的多普勒信号就会进入测速仪的接收系统，该信号将干扰甚至掩盖流场速度信号而导致测速失败。

Analysis of the Window Effect with LDV Application in Rotational Flow Field

In laser Doppler velocimeter application to rotational flow,the window effect will appear when measurement window rotates with the flow field.With experimental study and theoretical analysis,it is shown that if the distance between the measuring volume and the window is too small,signal of window rotational speed will enter into receiving system of the velocimeter and disturbs or even submerges flow velocity signals.To eliminate the window effect,the distance should be set as large as possible,with the optical receiving system properly adjusted.