Characteristics of Oscillation in Cavity of Helmholtz Nozzle Generating Self-excited Pulsed Waterjet
Abstract Cavity flow oscillations in the axisymmetric cavity are critical to the operating efficiency of self-excited pulsed waterjets, which are widely employed in many practical applications. In this study, the behaviors of a turbulent flow in axisymmetric cavities causing cavity flow oscillations...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
SpringerOpen
2022-06-01
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| Series: | Chinese Journal of Mechanical Engineering |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s10033-022-00714-3 |
| _version_ | 1817975459788357632 |
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| author | Miao Yuan Deng Li Yong Kang Hanqing Shi Haizeng Pan |
| author_facet | Miao Yuan Deng Li Yong Kang Hanqing Shi Haizeng Pan |
| author_sort | Miao Yuan |
| collection | DOAJ |
| description | Abstract Cavity flow oscillations in the axisymmetric cavity are critical to the operating efficiency of self-excited pulsed waterjets, which are widely employed in many practical applications. In this study, the behaviors of a turbulent flow in axisymmetric cavities causing cavity flow oscillations are investigated based on wall pressure characteristics. Experiments are performed using four Helmholtz nozzles with varying length-to-radius ratios at flow velocities of 20–80 m/s. Three orders of hydrodynamic modes in axisymmetric cavity are obtained through the spectral analysis of wall pressure. Based on the experimental results, the empirical coefficient of Rossiter’s formula is modified, and the values of the parameter phase lag and the ratio of convection velocity to free stream velocity are obtained as 0.061 and 0.511, respectively. In addition, the spectral peak with a relatively constant frequency shows that the flow-acoustic resonance is excited significantly. A modified model is introduced based on the fluidic networks to predict the lock-on frequency. The results obtained can provide a basis for the structural optimization of the nozzle to improve the performance of self-excited pulsed waterjets. |
| first_indexed | 2024-04-13T21:50:27Z |
| format | Article |
| id | doaj.art-c5786b22f557472ca84c11beaf973ed3 |
| institution | Directory Open Access Journal |
| issn | 1000-9345 2192-8258 |
| language | English |
| last_indexed | 2024-04-13T21:50:27Z |
| publishDate | 2022-06-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | Chinese Journal of Mechanical Engineering |
| spelling | doaj.art-c5786b22f557472ca84c11beaf973ed32022-12-22T02:28:27ZengSpringerOpenChinese Journal of Mechanical Engineering1000-93452192-82582022-06-0135111110.1186/s10033-022-00714-3Characteristics of Oscillation in Cavity of Helmholtz Nozzle Generating Self-excited Pulsed WaterjetMiao Yuan0Deng Li1Yong Kang2Hanqing Shi3Haizeng Pan4Hubei Key Laboratory of Waterjet Theory and New Technology, Wuhan UniversityHubei Key Laboratory of Waterjet Theory and New Technology, Wuhan UniversityHubei Key Laboratory of Waterjet Theory and New Technology, Wuhan UniversityHubei Key Laboratory of Waterjet Theory and New Technology, Wuhan UniversityHubei Key Laboratory of Waterjet Theory and New Technology, Wuhan UniversityAbstract Cavity flow oscillations in the axisymmetric cavity are critical to the operating efficiency of self-excited pulsed waterjets, which are widely employed in many practical applications. In this study, the behaviors of a turbulent flow in axisymmetric cavities causing cavity flow oscillations are investigated based on wall pressure characteristics. Experiments are performed using four Helmholtz nozzles with varying length-to-radius ratios at flow velocities of 20–80 m/s. Three orders of hydrodynamic modes in axisymmetric cavity are obtained through the spectral analysis of wall pressure. Based on the experimental results, the empirical coefficient of Rossiter’s formula is modified, and the values of the parameter phase lag and the ratio of convection velocity to free stream velocity are obtained as 0.061 and 0.511, respectively. In addition, the spectral peak with a relatively constant frequency shows that the flow-acoustic resonance is excited significantly. A modified model is introduced based on the fluidic networks to predict the lock-on frequency. The results obtained can provide a basis for the structural optimization of the nozzle to improve the performance of self-excited pulsed waterjets.https://doi.org/10.1186/s10033-022-00714-3Self-excited cavitation waterjetFlow-excited oscillationsFrequency characteristicsVibration analysis |
| spellingShingle | Miao Yuan Deng Li Yong Kang Hanqing Shi Haizeng Pan Characteristics of Oscillation in Cavity of Helmholtz Nozzle Generating Self-excited Pulsed Waterjet Chinese Journal of Mechanical Engineering Self-excited cavitation waterjet Flow-excited oscillations Frequency characteristics Vibration analysis |
| title | Characteristics of Oscillation in Cavity of Helmholtz Nozzle Generating Self-excited Pulsed Waterjet |
| title_full | Characteristics of Oscillation in Cavity of Helmholtz Nozzle Generating Self-excited Pulsed Waterjet |
| title_fullStr | Characteristics of Oscillation in Cavity of Helmholtz Nozzle Generating Self-excited Pulsed Waterjet |
| title_full_unstemmed | Characteristics of Oscillation in Cavity of Helmholtz Nozzle Generating Self-excited Pulsed Waterjet |
| title_short | Characteristics of Oscillation in Cavity of Helmholtz Nozzle Generating Self-excited Pulsed Waterjet |
| title_sort | characteristics of oscillation in cavity of helmholtz nozzle generating self excited pulsed waterjet |
| topic | Self-excited cavitation waterjet Flow-excited oscillations Frequency characteristics Vibration analysis |
| url | https://doi.org/10.1186/s10033-022-00714-3 |
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