共查询到19条相似文献,搜索用时 250 毫秒
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利用Pumplinx软件建立了某汽油机用叶片式可变排量机油泵的计算流体力学模型,对叶片式可变排量机油泵的空化现象进行了模拟及试验验证,结果表明,空化主要发生在机油泵泵腔内入口侧,空化程度随转速增大而加重,且空泡的主要成分为不凝结气体。对比了不同机油含气量、油温、机油粘度、入口压力和入口几何结构等条件下机油泵出口流量、叶片腔总空泡体积分数分布情况,结果表明,机油含气量、入口压力和入口几何结构对泵内空化程度影响较大,工质参数对泵内空化影响相对较小,减小机油含气量、增大入口压力可有效减少泵内空化程度。 相似文献
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研究1款小排量自然吸气发动机,通过将发动机机油泵由定排量机油泵更改为可变排量机油泵以达到降低发动机燃油耗的目的。根据项目的实际需求,优先考虑采用经济性较好、对周边零部件更改程度较小的机械式两级可变排量机油泵。首先根据发动机润滑系统各主要零部件的润滑需求确认发动机主油道的最优润滑油压力,其次根据主油道的供油压力确定变量泵的关键性能参数,最后通过发动机燃油耗对比试验确定该变量油泵应用后对降低该发动机燃油耗的贡献。 相似文献
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汽车发动机全程可变排量机油泵是一种通过比例电磁阀对油泵排量进行可控调节的机油泵。文章着重介绍了叶片式全程可变排量机油泵的工作原理和特性,针对其特性制定相应试验项目,对其试验台架方案进行研究分析。 相似文献
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澳大利亚墨尔本的斯凯尔佐汽车研究公司已研制出一种新型的车用发动机——连续式变冲程发动机,简称CVS。这种五缸变排量斜盘式发动机开动后噪声很小,手触发动机缸盖感觉不出振动。 相似文献
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本文就K6发动机机油泵调压阀开启压力对发动机机油压力的影响进行了试验总结,并对机油泵调压阀开启压力值进行了设计计算和分析,以便对今后类似问题的解决有所启迪和帮助。 相似文献
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车用柴油机活塞漏气量试验及其限值的分析 总被引:2,自引:0,他引:2
通过近期测试的多种车用柴油机活塞漏气量的试验数据对比,总结出了最大漏气量的主要分布规律,并对影响活塞漏气量的主要因素做了简要分析,对“12倍排量”限值提出了自己的见解,指出科学评测发动机活塞漏气量应兼顾发动机的排量、转速及最高平均有效压力。 相似文献
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本文首先介绍了车用催化转化器性能评价的三个阶段及其主要试验项目,介绍了常用的评价试验装置(机械性能实验台、发动机台架上净化性能试验台、快速老化实验台,装车评价试验装置四大试验台)的原理。主要就评价试验条件和性能指标进行了述评,最后进行了总结。 相似文献
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Gerotor pumps are widely used in the automotive industry for engine oil lubrication, due to their high volumetric efficiency
and smooth pumping action. In many cases, the lubricating oil from the sump is mixed with contaminants, such as dust and tiny
solid particles, or becomes thickened, due to aging. These problems will lead to critical situations, such as increased noise,
enhanced wear and erosion, and poor lubrication of the engine. These critical situations were studied by conducting a detailed
CFD integrated investigation on a gerotor pump’s performance at different operating conditions in three phases, and the results
are presented in this paper. In first phase, a CFD model of a gerotor pump was developed with a dynamic mesh for the rotary
movement of both the inner and outer rotors. The effects on pump flow rate of important parameters, such as rotor speed, fluid
viscosity and number of ports, were simulated using non-contaminated oil at room temperature and an elevated temperature of
140oC. The relationship between flow rate and pressure at different rotor speeds was predicted and validated with test data
for further parametric study. The pressure ripples at different time steps were measured at different angular positions of
the rotors to examine the model accuracy. It was found that the flow rate increased and pressure pulsation, as well as flow
recirculation, was reduced when ports were added to the cover plate. A suction pipe with a strainer was added for the second
phase to capture the undesired changes in flow behavior, such as cavitation, which is caused by negative suction at the inlet
region of pump. A suitable size for the inlet suction pipe for this pump was chosen after performing tests to characterize
the flow behavior with single and double ports. Next, the relationship between pressure drop and strainer porosity was determined
using different porosity values for the strainers. In the final phase, oil with different concentrations of solids was simulated
to measure the effect of solid particles on flow rates and pressure losses. It was observed that the intensity of the recirculation
was reduced at the suction end at the higher concentration of 0.04%, due to particle inertial effects. It was also found that
particle size distribution affected the overall efficiency and pressure head of the pump. 相似文献
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对于自动变速器油泵,可通过失速试验和时间滞后试验来检查油泵的性能和判断油泵有无故障。经分析认为,主动齿轮、齿环与泵壳凸台配合间隙超限,主动齿轮、齿环与泵壳接触面磨损量超限,以及O形圈老化或断裂是造成油泵性能下降的主要原因。 相似文献
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D. Danardono K. S. Kim E. Roziboyev C. U. Kim 《International Journal of Automotive Technology》2010,11(3):323-330
A roller vane type liquefied petroleum gas (LPG) pump was developed for a liquid phase LPG injection (LPLi) engine. Most of
the LPG pumps used in the current LPLi engines are installed inside of the LPG tank, but this pump is intended to be installed
outside of the LPG tank to overcome the difficulty of fixing an in-tank pump. Because LPG has a low boiling point and high
vapor pressure, it usually causes cavitation in the pump and consequently deteriorates the flow rate of the pump. The purpose
of this work is to optimize the design of the roller vane pump in order to suppress cavitation and increase the fuel flow
rate by using a computational fluid dynamics (CFD) analysis. In order to achieve these goals, the intake port configuration
and the rotor of the roller vane pump were redesigned and simulated using STAR-CD code. Computation was performed for six
different models to obtain the optimized design of the roller vane pump at a constant speed of 2600 rpm and a constant pressure
difference between the inlet and outlet of 5 bar. The computation results show that an increased intake port cross-section
area can suppress cavitation, and the pump can achieve a higher flow rate when the rotor configuration is changed to increase
its chamber volume. When the inlet pressure difference is 0.1 bar higher than the fluid saturation pressure, the pump reaches
its maximum flow rate. 相似文献
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柴油机燃油喷射系统流体动力学研究进展 总被引:1,自引:0,他引:1
针对柴油机燃油喷射系统的流体动力学问题,从影响模拟精度的角度出发,分别对燃油黏性、空化、燃油的变物性和流体-结构耦合等方面进行了综述,旨在为今后更加深入的研究提供参考。概述了柴油机燃油喷射系统流体动力学研究的发展现状,提出了未来发展的方向:开展高压油泵柱塞腔、喷油器控制腔和蓄压腔等腔体内燃油的高维流体动力学分析;考虑流体内部及流体-结构耦合传热引起的温度场变化;考虑燃油物性随温度和压力的变化及变化率;对喷射系统建立流-固-热强耦合瞬态分析模型,分析水击压力、管道振动及泄漏问题;继续进行燃油的高温高压特性测试。 相似文献
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以国内某新型轻客驱动桥的NVH性能为研究对象,根据整车噪声测试结果,结合驱动桥的噪声测量数据,并运用ABAQUS软件进行模态有限元分析。针对主减齿轮啮合噪声和驱动桥的整车共振提出相应改进措施,并进行试验验证。试验结果表明,理论分析计算和改进措施有效,为后期驱动桥的设计和改进提供了参考。 相似文献
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