Knowledge Management System of Institue of Mechanics, CAS
| 水下高速喷流噪声的产生机制与辐射特性 | |
| 江先金 | |
| Thesis Advisor | 戚隆溪 |
| 2000 | |
| Degree Grantor | 中国科学院研究生院 |
| Place of Conferral | 北京 |
| Subtype | 硕士 |
| Degree Discipline | 流体力学 |
| Keyword | 喷流噪声 水下气体喷流 线化欧拉方程 数值模拟 声场特性 Jet Noise Gas-jet In Water Linearized Euler Equations Numerical Simulation Acoustic Properties |
| Other Abstract | 在对喷流噪声研究进展广泛调研的基础上，本论文采用柱坐标下轴对称的线化欧拉方程（LEE）、空间四阶时间二阶精度的MacCormack差分格式，对水下气体喷流的混合噪声产生与辐射特性进行数值模拟研究。采用基于经验公式的积分计算方法来确定求解线化欧拉方程所需的平均流场，对边界条件给予特殊处理以避免声波通过时产生反射。本文计算声明，线化欧拉方程及其相应的高阶数值方法提供了一个可以预报水下气体喷流混合噪声传播的省时高效的途径。给出的结果指出：由于水介质的密度很大，水下气体喷流远场收集到的噪声强度比同样情况下空中气体喷流要小，这说明水下发射导弹更具隐蔽性。同时，由于水介质中的声速很大，水下的高速喷流噪声场呈现更加均匀的性态，而不是象空中混合噪声在下游沿一定的方向辐射。鉴于本文只考虑常温情况，气体喷流速度是影响喷流噪声产生与辐射的重要参数：马赫数增大，远场的噪声强度随之增大。另外，水下喷流噪声的特性还与扰动频率有关。; Based on the comprehensive survey of investigation progresses of high-speed gas-jets noise, the present thesis simulates numerically the properties of generation and radiation of mixing noise of gas-jets in water by using the axisymmetrical linearized Euler equations (LEE) in cylindrical coordinate system and the MacCormack scheme with forth-order accurate in space and second-order accurate in time. The mean flow quantities, needed in the linearized Euler equations (LEE), are calculated by an integral method based on empirical formula. In order to avoid sound reflection, special attention is give to the boundary condition treatment. The numerical computations show that the linearized Euler equations (LEE) and the adopted high-order accurate numerical method are effective and economic approaches for predicting turbulence mixing noise of gas-jets in water. The obtained results indicate that, because of high density of water, the far-field noise intensity of gas-jets in water is lower than that in air under the same condition, which renders the covert characteristics in underwater missile. Moreover, because of high sound velocity in water, the radiation of underwater jet noise is more uniform, which shows a different feature compared to the directivity of the jet noise in the air. For isothermol jets under consideration, the velocity of gas-jet plays an important role in the generation and radiation of noise: as Mach number of jet increases, the far-field noise intensity increases. Besides, the properties of underwater jet noise also depend on the disturbance frequency in the inflow. |
| Call Number | 29901 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://dspace.imech.ac.cn/handle/311007/23234 |
| Collection | 力学所知识产出(1956-2008) |
| Recommended Citation GB/T 7714 | 江先金. 水下高速喷流噪声的产生机制与辐射特性[D]. 北京. 中国科学院研究生院,2000. |
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| File Name/Size | DocType | Version | Access | License | ||
| 水下高速喷流噪声的产生机制与辐射特性.p（5687KB） | 开放获取 | -- | Application Full Text | |||
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