Simulation Analysis of Jet Noise from High-speed Railway EMU Main Circuit Breaker Switching Valve and Noise Reduction Measures
Journal Title: Urban Mass Transit - Year 2024, Vol 27, Issue 4
Abstract
Objective The jet noise generated by the main circuit breaker switching valve of high-speed railway EMU is excessively high, which seriously affects passenger comfort. Therefore, it is essential to study effective noise reduction measures. Method Field experiments are conducted to measure the jet noise of the switching valve, revealing a noise level as high as 96 dB with noticeable intermittency and pulsation. Using LES (large eddy simulation), a mathematical model for simulating the jet noise of the switching valve is established. Four different nozzle shapes are selected, and their flow velocity distribution nephograms are computed. The calculated jet flow results are imported into LMS.Virtual.Lab software, and the acoustic boundary element method is employed to simulate the jet noise fields of the four nozzles. The simulated 1/3-octave frequency spectrum values for them are compared with experimentally measured values. Finally, four existing industrial mufflers and a developed new structural composite material muffler are selected and tested for their noise reduction effectiveness on the switching valve. Result & Conclusion Generated by main circuit breaker disconnection, the jet noise of the switching valve is closely related to the shape of the exhaust port and falls into the mid-to-high-frequency noise range. All five mufflers can significantly reduce the jet noise from the switching valve, with the new structural composite material muffler demonstrating the best noise reduction effect, achieving a reduction of up to 20 dB.
Authors and Affiliations
Chao ZHANG, Zan JIANG, Junfeng WANG, Zhengsen LIU, Junyong WANG
Keywords
Related Articles
- EP ID EP734163
- DOI 10.16037/j.1007-869x.2024.04.017
- Views 56
- Downloads 0
Seepage Point Impact in Urban Rail Transit Station Foundation Pit Enclosure Structure on the Variation Law of Surrounding Groundwater Seepage Field
Objective In terms of underground engineering construction accident causes, approximately 20% of foundation pit accidents are caused by water seepage through enclosure structures. Such seepage can lead to significant def...
Safety Protection of Under-passing Existing Rail Transit Structures Based on Midas GTS Finite Element Software
［Objective］ With the rapid expansion of urban rail transit networks, the intersection of multiple lines has become a common phenomenon in urban construction. In particular, the increasing cases of newly constructed tun...
Development Prospect of High-reliability Urban Rail Transit Permanent Magnet Traction System Based on Digital Twin Technology
［Objective］ With the maturity of permanent magnet synchronous motor design and control technologies, PMTS (permanent magnet traction systems) have emerged as the developmental direction for next-generation rail transit...
Intelligent Health Management System for Rail Transit Signaling System Power Supply
Objective The dual-bus and dual-interruptible power supply (UPS) architecture in rail transit signaling system power supply enhances the system redundancy but does not effectively reduce component failure rates. To impro...
Key Technologies of Large-diameter Shield Tunneling in Sand and Gravel Strata
[Objective] Key construction technologies for large-diameter shield tunneling in sand and gravel strata are summarized and analyzed, including shield machine model selection, shield launching and receiving, and shield ex...