Abstract: Due to the structural differences between the in-sink dishwasher and the traditional vertical and cabinet-type dishwashers, the noise distribution and transmission paths of the in-sink dishwasher are different. By using the sound intensity method to locate and analyze the noise sources of the in-sink dishwasher, the noise sources and the noise contribution amounts at different positions can be accurately determined. Through the detection by the sound intensity method, it is found that the part of the door of the in-sink dishwasher directly impacted by the water flow is the main contributor to the overall noise of the dishwasher. Such accurate positioning provides a simple and efficient way to reduce the operating noise of the whole machine, enabling more targeted implementation of improvement measures. The noise control methods are flexibly adjusted according to different types of noise. The operation of the in-sink dishwasher generates various types of noise, including mechanical noise, water flow impact noise, etc. Different types of sound-absorbing and damping materials are applied to the door of the dishwasher for testing. Experiments show that in the comparative experiment of the three noise control solutions, the constrained damping solution shows the most prominent noise reduction effect, reducing noise by 3.1 dB(A) ; the sound-absorbing cotton solution comes next, with a noise reduction of 2.0 dB(A) ; the damping paste solution has a relatively weaker effect, reducing noise by only 1.6 dB(A) . From the data comparison, it can be seen that the constrained damping material has a remarkable effect in suppressing the noise generated by the vibration of the dishwasher door due to the impact of the water flow. Through effective analysis of noise sources combined with experimental verification, systematically investigates the noise reduction mechanism and practical application effects of constrained damping materials. The research provides theoretical foundations and practical references for similar applications.

Key words: In-sink dishwasher, Noise source, Sound intensity, Damping material