The Acoustic Vibration Analysis And Application On The Movable Blade Of Axial-Flow Fanner

With advanced model analysis and computer analogue technique, this very paper has made a deep research on the relationship between blade vibration and sound radiation of axial flow fan, worked out the relationship between structural vibration energy and sound radiation power, and made a full analysis about the characteristics of exciting frequency and noise sources. Theoretically, moving vane discrete has been made through finite element method. From deferential equation for natural frequency of moving vane, it has made a detailed analysis about the vibration characteristics of moving vane, and a deep exploration into sound radiation characteristics of moving vane, the effect of exciting force on acoustic vibration and the controlling means of acoustic vibration of moving vane. Practically, a research has been made to the structural dynamic property of moving vane through model analysis test on moving vane. By single-point stimulation of exciter, qualitative analysis has been made to the effect of acoustic vibration on stimulation, and verification to the theoretical research on acoustic vibration of moving vane, on the basis of which, the author has summarized the controlling means of acoustic vibration and put forward her own viewpoint about noise control of propeller fan. It has been put into practice changing the structural size of moving blade to reduce the dither effect of moving fan on exciting force, that is, changing the natural frequency of moving blade, in order to stagger the exciting frequency for vibration and noise reduction.As the result illustrates, the test tallies with the theory. Sound and vibration analysis can fully identify the source of noise, thus controlling the noise accordingly. It solves the noise problem and promotes the efficiency of axial flow fan, and is, therefore, practically significant.