【作者】 杨文强；

【导师】 柳贡民；

【作者基本信息】 哈尔滨工程大学 ， 轮机工程， 2010， 硕士

【摘要】 喷注噪声广泛存在于人类生产生活中,目前已成为影响人身健康和设备安全的重要原因之一。本文在对气动噪声理论,特别是喷注噪声产生机理、理论估算方法、仿真计算方法以及实验测试方法消化吸收的基础上,利用理论、数值仿真及实验方法研究了孔群喷注噪声的声源特性。文章首先利用大涡模拟计算了二维管内单孔受限喷注的流动和噪声特性。仿真计算结果表明,管内喷注噪声具有指向性,声压级随喷注距离的增加逐渐减小,且峰值频率基本与理论相符。然后利用理论方法推导了孔群喷注噪声声压级的估算公式,并利用实验对得到的公式进行了验证和修改。研究发现,对于大孔间距孔群,估算公式基本与实验测量相符,对于小孔间距孔群,即计及孔群汇合喷注噪声的总声压级估算公式,通过实验数据拟合,也能够用来估算孔群喷注噪声。对原有减温减压器结构进行了改进设计,并对其进行了流场仿真计算和噪声特性的实验研究。研究结果表明结构的振动噪声级与原型相比有所减小,达到了降低减温减压器振动噪声级的目的,对减温减压器的进一步结构和性能改进具有参考价值。更多还原

【Abstract】 Jet noise, widely existing in human life, has become one of the main factors which affect human health and safety of equipments. Based on the thorough learning of aerodynamic noise theory, especially the jet noise generation mechanism, theoretical calculation methods, simulation methods and experimental testing methods, the sound source characteristics of multiple jets noise is investigated by theoretical, simulation and experimental methods in this paper.At first, the flow and noise characteristics of two-dimensional restricted jet in pipe are simulated by the Large-Eddy Simulation method. The results show that the jet noise in pipe has directivity, and the peak frequency is coincident with theoretical calculation results..Then, using the theoretical method, sound pressure level estimating formula of multiple jets noise is obtained, and then it is validated and modified with the experiment results. The study shows that for micro pores with large space between holes, the estimating formula is consistent with the experimental data, also for the micro pores with small space between holes, namely, the overall sound pressure level considering jet noise caused by multiple jets converging, by fitting the experimental data, the formula can be also used to estimate the sound pressure level of jet noise.At last, the paper improves the Temperature and Pressure Reducer design, which is with characteristics of multiple jets noise, simulates the flow field and experimental studies the jet noise characteristics. The research results show that the vibration and sound level are smaller than the prototype. This achieves the aim of decreasing the vibration and noise level, and the results are of reference value for the structure and performance improvements to the Temperature and Pressure Reducer.更多还原