Due to the continuous development of electronic products, the problem of cooling fan noise is receiving increasing attention. Especially, in recent years, low noise has become a highly competitive factor in the purchase of fan equipment. The design of low-noise fans and the noise reduction methods are the urgent demand of manufacturers as well as consumers. This paper summarizes the present noise analysis and reduction methods of cooling fans. It focuses on the source and the physical essence of noise, numerical simulation and the passive as well as active noise control methods.
The theory of life prediction is the key foundation of the safety service of electromechanical device, and it is also an important aspect of modern mechanical design and manufacturing. Life prediction for major mechanical equipment has great significance for economic development and defense construction. This paper aims at the investigation of characteristics and applications of electromechanical device life prediction techniques. It summarizes the current progress of life prediction based on data-driven methods. The challenges of electromechanical device life prediction include theoretic models, experimental validation, data accumulation. It provides a possible direction for further research on life forecasting method.
This paper presents a bearing fault diagnosis algorithm based on human self regulating particle swarm optimization and stochastic resonance. The algorithm first sets up the objective function according to the stochastic resonance structural parameters a and b. Then the self regulating particle swarm optimization algorithm is used to optimize the objective function, and the optimized optimal values a and b are substituted into the system of variable scale stochastic resonance. Finally, the measured bearing vibration signal to noise reduction and spectrum analysis to find the bearing fault characteristic frequency. Experimental results show that this method is effective in bearing fault diagnosis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.