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- Chen, Fuqiang, et al.
(författare)
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减压阀噪声研究进展
- 2019
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Ingår i: Paiguan Jixie Gongcheng Xuebao/Journal of Drainage and Irrigation Machinery Engineering. - 1674-8530. ; 37:1, s. 49-57
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Tidskriftsartikel (refereegranskat)abstract
- In order to comprehensively understand the specific noise generation process inside pressure reducing valves (PRV) and its existing research outcomes, the generation of noise in PRV with its research methods in China and abroad was summarized. Then, the current research status of noise reduction technologies was reviewed from two aspects: source and propagation. Based on analysis and summarization, the major existing problems in current noise reduction technologies were discussed, including complex flow situation in PRV, ambiguity of vortex location and uncertain of interaction between high-velocity jet flows and so on. In the future investigation of noise reduction in PRV, it is advised that the position of noise source in valve should be determined firstly through combination of theoretical analysis, experiment and numerical analysis. Then, the directivity of noise in the valve can be clarified. Thereby, a further study of noise reduction mechanism and technology can be launched. Finally, noise in PRV can be reduced to the utmost extent. In the future, control of noise inside PRV should start with flow mechanism and structural innovation, and then a universal valve design theory with low noise will be put forward. Investigation into noise characteristics in pressure reducing valve can provide a reliable basis for reducing noise effectively.
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| 2. |
- Kang, Yachi, 1990-, et al.
(författare)
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Numerical simulation of pressure distribution in bristle seal for turbomachinery
- 2018
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Ingår i: Paiguan Jixie Gongcheng Xuebao/Journal of Drainage and Irrigation Machinery Engineering. - : Editorial Department of Journal of Drainage and Irrigation Machinery Engineering. - 1674-8530. ; 36:5, s. 420-425
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Tidskriftsartikel (refereegranskat)abstract
- In order to further study the pressure distribution in bristle seals, a uniformed two-dimensional closed staggered tube bundle model representing a bristle pack cross-section was proposed and the fluid flow through the bundle was solved by computational fluid dynamics(CFD) method. Accor-ding to the critical Reynolds number for boundary layer transition, a new method was proposed to decide the fluid flow regime in the bundle. The pressure and velocity distributions in the bundle were studied under various pressure differentials across the seal. The influences of distance between bristles and number of circumferential bristle rows on the pressure distribution were tackled. It is shown that the pressure distributions in the uniformed two-dimensional closed staggered tube bundle model agree well with the previous experimental data. The pressure distributions are like "V", while the velocity distributions are like the inverted "V". The pressure borne by the rear 1/3 part of the bristle pack is higher than that by the front 2/3 part. Moreover, the percentage of the pressure differential borne by the last 5 bristle rows increases with increasing total pressure differential. The pressure differential borne by the last bristle row is higher than that by a few rows in front of it. A reduced distance between bristles can allow the pressure to be distributed more even from one row to another. Bristles equally spaced can ensure an even pressure distribution rather well. Increasing the number of rows can also have the same effect. © 2018, Editorial Department of Journal of Drainage and Irrigation Machinery Engineering. All right reserved.
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