In this paper, it was presented that a simple method for calculating the distribution of the pistonlike sound fields, which extends the approach proposed by Wen and Breazeale. The distribution function on the source i...In this paper, it was presented that a simple method for calculating the distribution of the pistonlike sound fields, which extends the approach proposed by Wen and Breazeale. The distribution function on the source is expressed as the product of one function and a Gaussian sum of the step function, and the calculation of the sound fields reduces the estimation of sums of some relatively simple functions such as the M-shape and Gaussian ones. Some of pistonlike fields are evaluated, and the results indicate that this approach is very successful.展开更多
In this paper,the flow field around NACA0015 hydrofoil is calculated under the condition of two-phase cavitating flow to provide a theoretical guidance for reducing the cavitation noise.A modified turbulence model cou...In this paper,the flow field around NACA0015 hydrofoil is calculated under the condition of two-phase cavitating flow to provide a theoretical guidance for reducing the cavitation noise.A modified turbulence model coupled with the Zwart cavitation model is used to calculate the flow field.According to the computed sound source data,the dipole sound pressure distribution diagrams for the extremely short time and the complete time around the hydrofoil under different working conditions are obtained.The sound pressure distribution and the sound pressure amplitude are analyzed in detail.In addition,the field points around the hydrofoil are selected to generate the corresponding frequency response function curves,which are analyzed from the aspects of the trend,the variation and the extreme value.The results show that the dipole characteristics are gradually diminished and finally disappear with the increase of the frequency.At the frequency of the vapor volume fraction fluctuation,the noise level at the field point will have an extreme value.展开更多
文摘In this paper, it was presented that a simple method for calculating the distribution of the pistonlike sound fields, which extends the approach proposed by Wen and Breazeale. The distribution function on the source is expressed as the product of one function and a Gaussian sum of the step function, and the calculation of the sound fields reduces the estimation of sums of some relatively simple functions such as the M-shape and Gaussian ones. Some of pistonlike fields are evaluated, and the results indicate that this approach is very successful.
基金Project supported by the National Natural Science Foundation of China(Grant No.51806058)the Fundamental Research Funds for the Central Universities(Grant No.B200202170)。
文摘In this paper,the flow field around NACA0015 hydrofoil is calculated under the condition of two-phase cavitating flow to provide a theoretical guidance for reducing the cavitation noise.A modified turbulence model coupled with the Zwart cavitation model is used to calculate the flow field.According to the computed sound source data,the dipole sound pressure distribution diagrams for the extremely short time and the complete time around the hydrofoil under different working conditions are obtained.The sound pressure distribution and the sound pressure amplitude are analyzed in detail.In addition,the field points around the hydrofoil are selected to generate the corresponding frequency response function curves,which are analyzed from the aspects of the trend,the variation and the extreme value.The results show that the dipole characteristics are gradually diminished and finally disappear with the increase of the frequency.At the frequency of the vapor volume fraction fluctuation,the noise level at the field point will have an extreme value.
