Reasons for noise of FRP fan
1. One is propeller noise caused by the pressure field of rotor blade movement; the other is blade pulse dynamic noise caused by aerodynamic interference. The distance between FRP wind moving blades and static blades is an important factor of interference noise.
2. When this distance is very small, both potential flow and wake changes will have an impact, and blades may also act as acoustic barriers to enhance the acoustic radiation generated by the lift pulsation on the adjacent blades. This effect depends on the ratio of the wavelength of the sound wave related to the lift pulsation to the size of the barrier blade. The change in radiation intensity due to this effect is significant in the frequency range where the ratio is greater than 2. Therefore, when the upstream and downstream of a blade with radiated noise have the same number of blades, and each blade in the two rows meets a rotor blade at the same time to form a sound barrier on both sides of the source, the effect will be stronger.
3. When the distance between moving and static blades increases, the influence of potential flow interference decreases much faster than the influence of wake velocity change, and the effect of FRP fan blade as sound barrier also decreases with the increase of distance. It can be seen that at least three parameters affect the size of interference noise: the blade shape of the velocity field waveform (i.e., the blade load), the distance between the blade columns and the blade radiation area as the sound source. A very small spacing may produce two acoustic effects. If the static blade interference field establishes a force pulsation on the moving blade, the moving blade becomes a sound source, while the static blade is a sound barrier.
FRP fan shell and impeller are FRP material, corrosion resistance, acid and alkali resistance, according to the different resin materials, high temperature resistance is also different, the basic high temperature resistance of 60-80℃. Hope the above content can help everyone.