Study on Analysis of Noise Source for the Rotating Part of Large Radar

摘要

A large radar, which is continuously rotated at low speed (5-RPM), is able to detect the 3D position of aircraft or missiles. Noise from the rotating part of this radar may occur during rotation due to its very large size and heavy weight. In this paper, computational simulation and various analyses were performed to investigate the reason of this "ticking" noise during the rotation of a large radar. It was possible to roughly predict the area where the noise was generated by using a commercial acoustic analysis program. Torque checking the bolt, injecting grease for the bearing lubrication, measuring the horizontal deflection, and detecting the noise position with a real-time sound camera image were carried out to decrease the noise and analyze the noise source accurately. Moreover, the design of the large radar was rechecked based on the guide for appropriate bearing installation and the design of the rotating part. As a result, it has been realized that complex sources/parameters, such as the design, installation, lubrication, and bolt torque, may affect the noise of the rotating part. Furthermore, it was also been identified that the structural stability of the rotating part does not have a problem through the vibration inspection based on the ISO specification even though the noise occurred or increased. In conclusion, it is impossible that the mechanical noise of the large radar does not occur perfectly during rotating due to its large size and heavy weight, but it can be minimized according to the above management and design guide.