fdf

The criterion for judging flow reversals can be obtained through FDF theory.

而FDF理论分析可得出一个壁面（冷壁）或两个壁面均出现倒流的判断准则。

The simulation results illustrate that the FDF detected the faults occurred in different sensors effectively.

实验结果表明，故障诊断滤波器对发生在不同传感器上的故障进行了有效的检测。

When designing FDF system of compact spinning, the negative pressure drops resulting from spindles at the front and back of the machine should be kept within allowance.

在紧密纺大风机系统设计中，车头、车尾各锭的负压差异要保持在允许误差范围之内。