进气噪声原理的研究探讨与降噪措施

对进气噪声的产生原理进行分析和研究,利用赫姆霍兹谐振消声器的设计原理,设计了适合某车型的谐振腔,降低了进气噪声的声压级。消声降噪效果明显。     

Application of a sound insulation panel with ventilation holes to the engine under-cover

Reducing engine noise is one of the most important issues in lowering vehicle exterior noise. An engine under-cover is one effective measure for reducing engine noise. However, the size of the under-cover is limited by the need to ensure sufficient engine cooling performance. To solve this problem, a new sound insulation panel with ventilation holes was developed and applied to the engine under-cover. The panel accomplishes sound insulation by controlling the acoustic anti-resonance of sound waves transmitted through the ventilation holes. This paper describes guidelines for applying the panel to the engine under-cover from the viewpoints of acoustics and fluid dynamics.     

声强测量技术在发电机组噪声控制中的应用

针对目前我军装备的6135柴油发电机组噪声大,影响人员正常工作这一问题,利用声强测量分析方法对发电机组噪声源进行了识别,得出了其声场分布规律,在此基础上设计出具有针对性的方舱降噪结构.     

降低车内噪声的声学包优化研究

针对某车车内噪声偏大的问题,对整车声学包进行了材料与声学性能方面的优化,并对优化后的零部件声学性能进行了对比测试,同时通过对整车车内声压级和语言清晰度进行了对比测试,测试结果表明,声压级降低了2dB(A)左右,语言清晰度提升了大约10%,达到了车内降噪的目的,提升了客户满意度。     

浅谈黄海城市客车的车身降噪

本文通过噪声产生机理及噪声控制手段的分析，阐述黄海域市客车的车身降噪改进措施     

车内减振降噪技术的研究

分析了汽车车内噪声产生的机理,评述了车内噪声被动控制技术的三个途径,并对主动控制技术在汽车减振 降噪领域的应用作了探讨和展望。     

Development of the braided wire damper for exhaust radiation noise reduction

Single pipes used in a conventional vehicle exhaust system are not enough to reduce exhaust noise to a satisfactory level, especially at high frequencies. Double pipes are effective for reducing noise, but still not enough, and they are heavy. The new method, `Braided Wire Damper’, is an exhaust pipe partly wrapped with braided wire net. Proposed here is the use of `Braided Wire Damper’ and it is found to be very effective for reducing not only the noise but also the weight of the exhaust system.     

基于仿生学的客车风扇分析及其降噪优化

分析研究了影响客车风扇噪声和流量的主要因素,选取叶片边缘锯齿、叶片表面V槽设计和带Gurney襟翼叶型等主要部件和参数作为研究对象。采用仿生学原理对各因素进行了单因素仿真分析,并用图表展现各因素在一定区间内变化时风扇噪声和流量的变化规律。在此基础上,设计了两款特点鲜明的仿生风扇模型,并进行了仿真分析。     

Improvement of performance and exhaust emission characteristics in gas engine by heat release control

By either multiple direct injections coupled with an individual ignition or multiple ignitions in a premixed charge, the combustion process can positively be changed. The experimental results show that the heat release rate is changed widely depending on the flame ignition timing, and the possibility to bring about a preferable combustion could be shown. Numerical simulations of the cycle performance are carried out using a specially developed numerical simulator, involving the multi-zone combustion models. The results of the calculation using the multi-zone model show that a significant amount of NO_x appears in the zone formed in the early combustion stage.     

用于快速修复的冷补材料室内性能对比介析

选择两种快速修复的冷补材料,通过强度试验、飞散试验、残留稳定度和冻融劈裂试验、抗滑试验,研究路用性能.试验结果表明,两种材料均可以满足相关性能要求,但在具体性能指标上科宁冷补料安固补路通冷补料之间仍然有所差别.     

Improvement of loading cam performance in a toroidal CVT

This paper describes a new loading cam that always applies the optimum loading force to the variator used in a toroidal continuously variable transmission (CVT). The hysteresis of the loading force is shown to be caused by the spinning loss of the cylindrical cam roller of the conventional loading cam. This hysteresis is greatly reduced in the new loading cam by using a tapered cam roller that is free of spinning loss. Reducing the hysteresis lowers the average loading force, enabling the new loading cam to improve the torque capacity of a CYT.     

6130增压柴油机性能改进研究

本文通过对6130ZT_1柴油机的分析,提出了若干改进措施,并通过试验研究,探讨了涡轮增压器、配气相位、供油系统参数等对发动机性能的影响,从而提出了改善发动机性能的技术途径。     

6140GQ型城市客车车身地板降噪的优化设计

针对6140GQ型城市客车车内噪声偏高的问题,对车身地板结构进行了优化设计,新结构及新密封工艺的运用,降低了车内噪声。     

Analysis of acoustic radiation characteristics of engine compartment and application to reduction of vehicle pass-by noise

With the growing interest in environmental problems, the control of vehicle pass-by noise has become stricter. In this paper, the acoustic radiation characteristics of the engine compartment are investigated to reduce effectively noise radiated from the engine. These characteristics were found to vary with relative position of the noise source on engine surface and edge of body panel. The evaluation method was improved by considering these characteristics on engine component bench testing. This makes it possible to predict accurately the effect of modifying the engine structure on the pass-by noise test.     

汽车座椅动态试验CAE分析及结构优化

通过构建某车型后排座椅骨架的有限元分析模型,根据欧洲经济委员会ECER17法规中关于座椅抗惯性的动态试验标准要求,对某汽车后排座椅进行抗惯性动态试验仿真分析。仿真分析结果揭示了座椅结构的应力集中位置,以及座椅结构中容易导致试验失效的薄弱环节,为正确设计以及合理调整改善结构方案提供了依据。通过优化设计,完善了产品的结构。     

二灰稳定冷再生混合料路用性能研究

对二灰冷再生混合料的路用性能,包括强度、收缩特性、水稳定性与抗冻性进行了试验研究,以确定二灰冷再生混合料作为公路基层或底基层的可行性。研究表明,二灰稳定冷再生混合料强度可满足各级公路二灰混合料底基层强度的规范要求;其收缩性能比二灰土和石灰土好;同时具有良好的水稳性和抗冻性能。因此适合作为路面基层或底基层。