Numerical and experimental analysis on the vibration and radiated noise of the cylinder washing machine

Abstract The radiated noise of washing machines plays a pivotal role in user experience. Several studies have provided evidence that the low-frequency vibration of washing machine makes great contributions to its radiated noise. Unlike high-frequency noise, low-frequency noise decreases slowly and its wavelength is longer, so it can easily pass through obstacles and bring out a far-reaching impact on human health. Recently researchers pay intense attention to decease the low-frequency noise caused by household washing machines. The infinite element method (IFEM) is relatively simple and practical in simulating infinite region among numeric methods in acoustic computing with low frequency. Besides, IFEM could be coupled well with FEM and has high computational efficiency in low-frequency domain. Accordingly, our work introduces FE-IFEM into the prediction on the radiated noise of the washing machine. In this work, we analyze the dynamic characteristics and accurately estimate the radiated noise based on FE-IFEM. Firstly, the finite element model of washing machine is established and the natural frequency is measured to ensure the reliability of the model. Furthermore, the rigid-flexible coupling dynamic model is constructed to analyze the vibration and the vibration response test is carried out to verify the estimates of dynamic analysis. Finally, the radiated noise of the washing machine is calculated by using FE-IFEM and the noise experiment is performed. The simulation results are compared with the results obtained from the experiment and we conclude that the simulation estimates are in good agreement with the measured results. The maximum error obtained by this method is less than 6 dB. It indicates that FE-IFEM is an appropriate choice for predicting the radiated noise of washing machines in the low-frequency domain.