排气消声器优化模型探讨

将噪声源、消声管路和外界组成一般排气系统,对消声器消声特性进行计算,运用传递矩阵法给出了消声器插入损失的数学模型,分析了消声器内压力的损失及消声器目标消声量的频带特性对消声器优化设计的影响,提出并建立了兼顾消声器各项设计要求的新优化设计模型。运用BorlandC 和Matclab对新优化设计模型进行了计算,并编制了优化软件,最后对计算模型的预测精度和优化效果进行了试验室动态试验,证实计算和新建优化模型理正确可行的。     

ZY1000型筒体纵缝咬边机的研制

叙述了汽车消声器ＹＺ１０００型筒体纵缝咬边机的结构与工作原理以及芯模、抱合装置、精密滚轮和升降装置等工作部件的设计技术方法。     

ZH1105型柴油机排气噪声的控制

文中论述了一种适用于ＺＨ１１０５型柴油机的新型消声器,并详细分析了它的结构与性能。此消声器与原消声器相比具有更好的消声性能和空气动力性能。     

Pressure analysis on two-step high pressure reducing system for hydrogen fuel cell electric vehicle

Hydrogen fuel cell electric vehicle (FCEV) can achieve zero exhaust emission and zero pollution. In order to make FCEV reach a farther travel distance, greater demands are put on its pressure reducing system. In this paper, a two-step high pressure reducing system for FCEV is proposed. The system is made up of two parts, a new high multi-stage pressure reducing valve (HMSPRV) and a multi-stage muffler. As a new system, its feasibility has to be verified. Since the valve opening condition has a great effect on hydrogen flow, pressure reduction and energy consumption, different valve opening conditions are taken as the research point. The flow field analysis of the new HMSPRV is conducted on three aspects: pressure field, velocity field and energy consumption. It can be found that both the pressure reducing and velocity increasing gradients mainly reflect at those throttling components for all valve openings. For energy consumption, in the comprehensive study of flow vortexes and turbulent dissipation rate, it can be found that the larger of the valve opening, the larger of energy consumption. Then, a thermo-fluid-solid coupling analysis is conducted on the new HMSPRV, and it is concluded that the new system meets strength requirement. Furthermore, as the second step of the high pressure reducing system, the flow and pressure fields of multi-stage muffler are investigated. The five-stage muffler is exactly designed to complete the whole pressure reducing process. This study can provide technological support for achieving pressure regulation in the hydrogen transport system of FCEV when facing complex conditions, and it can also benefit the further research work on energy saving and multi-stage flow of pressure reducing devices.     

锚杆钻机气动马达微穿孔板消声器的理论分析与实验研究

在微穿孔板消声理论的基础上 ,根据气动马达消声器的实际需要设计了一种微穿孔板消声器 ,并通过实验对这种消声器的消声特性和流阻进行了研究。实验表明 :这种消声器能降低噪声 15dB以上 ,对特定频率的噪声具有优异的消声效果     

水泥磨主排风机排风筒的噪声控制研究

针对某水泥厂煤磨房主排风机排风筒50～5 000 Hz宽频噪声的特点，设计了多孔吸声材料、无纺布和多孔板复合结构的阻性片式消声器。结合多孔吸声材料DB-Miki模型理论、声波透反射原理和声致循环流原理，建立消声器消声区域的等效声阻抗率数学模型，然后结合有限元法和传递矩阵法求解阻性片式消声器的传递损失，通过与实验测试的结果对比证明了该方法的正确性。在此基础上对阻性片式消声器内玻璃纤维棉的体积密度和纤维直径进行参数优化，结果表明选用纤维直径为10μm、体积密度为60 kg·m-3规格的玻璃纤维棉的降噪效果最好。最后通过工程实例证明阻性片式消声器设计的合理性，为解决排风管道噪声问题提供了一定的参考。     

抗性消声器中含穿孔管时的声传递矩阵

本文在前文的荐进一步分析穿孔管与主管道垂直交叉时的声传播特性，导出了相应结构声传递矩阵的精确计算公式。文吧一种含穿孔管元件的典型结构为例，阐明了抗性消声器总的声传递矩阵分析计算方法，并作了讨论。