Numerical simulation of aerodynamic noise and noise reduction of range hood

The hybrid CAA (Computational Aeroacoustics) method is used to numerical study on the aerodynamic noise of a certain range hood. The CFD numerical calculation method was used to calculate the unsteady flow field, and the velocity and pressure distribution of the range hood under unsteady conditions were obtained. The particle imaging velocimetry (PIV) technology experiment was carried out by set up an internal flow field test bench, to record the flow status of the flow field in the measurement area by a CCD camera. Also, applied with FLUENT and Actran acoustic software, and based on the results of unsteady flow field calculation of the range hood as well as the Lighthill sound analogy method, the internal flow field information of the range hood is converted into the sound field information, and the noise of the range hood can be numerically simulated. The results showed that the range hood noise mainly concentrated on low and middle frequencies and characterized by discrete noise. The noise of the range hood Having distinct feature of direction at the blade passing frequency, and the noise is mainly transmitted to the outside through the main air inlet and secondary air inlet of the centrifugal fan in the range hood. Installing noise reduction structures at the main and secondary air inlet can effectively reduce noise.