共查询到20条相似文献,搜索用时 171 毫秒
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为提高减振器阻尼力输出的准确性及减振器性能可靠性,定量分析双筒式液压减振器尺寸参数及其公差、油液黏度等对阻尼力的影响。根据阻尼力的产生机理,建立了减振器复原行程中复原阀开启前、后的阻尼力模型和压缩行程中压缩阀开启前、后的阻尼力模型,利用MATLAB仿真得到了其示功图和速度特性图,并通过台架性能试验进行了验证。考虑到阻尼力模型的复杂性,采用ANSYS中的Design Exploration模块,利用响应面法得到了减振器各个参数的灵敏度,并针对油液黏度、阀系开启高度等影响较大的参数,考虑其随机性,利用蒙特卡洛抽样方法得到了减振器阻尼力的分布,从而为双筒式液压减振器的设计提供了依据,为进一步研究减振器的阻尼力退化及寿命评估奠定了基础。 相似文献
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《振动与冲击》2015,(21)
液力减振器内部的振动及冲击是其噪声产生的原因,通过实验和理论分析发现,该振动与冲击主要表现为空程冲击。为揭示液力减振器油液与活塞之间的空程冲击的具体过程和机理,首先通过建立数学模型,计算得到了某一减振器在不同激励下的空程距离;然后采用ADINA软件建立了模拟该减振器空程冲击过程的气-液两相有限元模型,并进行了流固耦合动态仿真;最后分析了活塞杆加速度的时域和频域响应。研究结果显示:流通阀阀片打开瞬间,油液与活塞的空程冲击将使活塞杆产生显著的轴向振动;随着空程距离增大,活塞杆轴向振动越明显。仿真计算结果与减振器噪声实验结果相符,表明该模型理论及其计算方法可解释减振器噪声产生的原因,并为降噪提供参考。 相似文献
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针对传统的双筒型磁流变液减振器底阀容易堵塞和单筒浮动活塞密封困难的问题,提出了一种单筒复合节流充气气囊补偿的磁流变液减振器。利用实验数据辨识了磁流变液的Herschel-Bulkley本构模型参数;建立了环形阻尼通道内磁流变液准稳态流动微分方程,利用Herschel-Bulkley本构模型得出了磁流变液速度分布表达式;研究了非牛顿流体环形通道节流、牛顿流体小孔节流和气囊补偿共同作用下的阻尼力计算方法。根据某轿车悬架参数要求,设计制作了磁流变液减振器样机;利用WDTS型油压减振器实验台对其进行了示功特性测试。测试结果表明:在不同电流激励作用下,磁流变液减振器的理论阻尼力值和测试值吻合较好,所提出的分析方法是合理的。 相似文献
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针对单一的性能评价指标无法表征磁流变液减振器的整体性能、难以实现减振器工作性能最优化的问题,采用试验测试方式,结合最大输出阻尼力、响应时间、示功曲线饱满程度等多个性能评价指标分析减振器在不同外部激励电流与激振速度下性能的变化规律。研究表明:最大输出阻尼力随外部激励电流的增大而增大,且输出阻尼力在活塞运动速度较小时受活塞运动速度的影响较大,在活塞运动速度足够大时受活塞运动速度的影响较小;活塞运动速度的增加会缩短减振器响应时间,阶跃电流的大小对响应时间的影响较小,但减振器的阶跃下降响应时间比阶跃上升响应时间长;在减振器装配过程中常存在的磁流变液灌装不足与体积补偿装置气体压强选择不当的问题会造成示功曲线发生畸变导致减振器的能量耗散性下降。研究结果可为磁流变液减振器的性能优化提供参考依据。 相似文献
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以双筒式液力减振器为研究对象,通过分析其工作原理及结构特征,运用AMEsim仿真平台建立减振器一维仿真模型。以某型国产车用减振器的结构参数为例进行了仿真,结合减振器台架性能试验进行多个工况下的模型验证。结果表明运用AMESim所搭建的仿真模型能较好地描述车用液力减振器的真实工作情况。运用该仿真模型可以较为全面地研究覆盖节流阀片刚度、节流孔面积和充气压力等25个减振器常规设计参数在多个典型运动工况下对示功特性的敏感性大小及变化趋势。为普通双筒式液力减振器的开发及改进提供了清晰的思路和方向。 相似文献
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为了优化压缩机的制冷量、功率、噪音和寿命,以研究无升程限制器的吸气阀运动规律为目标,确立数值模拟和物理试验相互佐证寻求最佳阀片结构的基本思路.将制冷剂的流动场和阀组构成的结构场耦合起来模拟阀片的运动,利用ADINA流固耦合模块(fluid-structure interaction,FSI),基于流体质量、动量、热量守恒定律和平板振动模型,得到了吸气过程中的阀片位移、缸内压力、吸气速度及阀片与阀座接触力的时程变化曲线.分析了阀片设计参数对其动态响应的影响,发现减小厚度可以优化压缩机性能,根据最大有效流通面积准则,得到了WS75YV型号压缩机的吸气阀最小即最优厚度.欧拉坐标系下制冷剂的速度分布及气缸内温度随时间的变化过程的模拟结果表明,压缩机吸气过程存在过热现象.采用第二制冷剂量热计法测量压缩机的制冷量、电机功率和其比值(coefficient of performance,COP),对比压缩机性能的理论和模拟计算值,证明流固耦合模拟方法可行,基于此对压缩机进行设计和优化是可靠的. 相似文献
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基于三维流-固耦合有限元动力学仿真分析模型和直接耦合算法,分析了一种锥形节流阀在入口流速脉冲激励下由关闭状态开启而后重新关闭全过程的流量特性、压差特性及阀门开度的高频波动等非线性动力学响应特性,并采用小波分析方法等对阀门开度响应等进行了时-频域分析。选择不同的流体-结构模型的数值积分方法组合及时间步长对流-固耦合动力学求解算法进行了实际应用检验;然后对阀芯质量、弹簧参数与油液参数等系统参数以及激励速度幅值与脉宽等激励参数对其工作过程动力学响应的影响进行了细致的数值分析比较。结果表明:流体模型积分算法的选择对流-固耦合计算结果的影响较大;对该阀而言,阀芯质量与油液体积弹性模量的改变对阀芯振动频率的影响较为显著,油液粘度的改变对阀门开启的滞后量及振动相位的影响较大,而弹簧刚度及预紧力的改变对阀门的最大稳定开度的影响较大;阀芯与阀座间的碰撞使阀芯的振动频率提高。 相似文献
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The cooling performance of GM type pulse tube cryocoolers (PTCs) is strongly affected by the valve setting for phase shifting. In this research, the effects of different valve openings on the no-load temperatures in a two-stage GM PTC have been investigated by numerical simulation. Results show that the no-load temperature at the 1st stage mainly depends on the openings of 1st stage orifice valve, and both 1st and 2nd stage double-inlet valves. While the no-load temperature at the 2nd stage below 10 K sensitively depends on the openings of both 1st and 2nd stage orifice valves, and 2nd stage double-inlet valves. There exist several local minimum no-load temperatures at the 2nd stage under different valve openings below 7 K. The best valve setting corresponds to minimizing the cold end phase angle, making the cold end acoustic power compensate the real gas enthalpy flow with maximum degree. 相似文献
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In a direct coal liquefaction unit, pressure relief valves locate on the pipeline between the atmospheric and vacuum towers. Failures of the valve components occur frequently owing to the harsh operation conditions. A combined numerical-experiment investigation on the failures of valves is conducted in this paper. The variation of relative erosion rates of WC–Co coating with impact angles, the function of relative particle velocity, and the distribution of particle diameters are obtained from the high-temperature erosion experiments. Furthermore, the erosion mechanism of WC–Co coating under large impact angles is clarified. In the numerical simulation, the evaporation–condensation, particle motion, erosion, and the modified RNG k-ε turbulence models are used to analyze the phase transition and particle erosion in the valves. Results showed that: due to the high pressure drop and convergent–divergent structure of angle valve, the coal-oil slurry flashes as it enters into the valves. The evaporation of liquid oil produces a large amount of vapor oil, and results in a rapid increase in flow velocity. High concentration solid particles, driven by the high-speed stream, tend to erode the inner surface of valves. Severe erosion can be found in the spool of angle valve, downstream bushings at the angle valve and ball valve. The calculation results agree well with actual failure morphologies, verifies the accuracy of the present prediction method. 相似文献
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对内调相型脉管制冷机进行热力学理论分析.内调相型脉管制冷机的特点是两个冷头在脉管热端通过针阀串联,两边脉管内的压力和流量耦合,通过调节各自的输入压力相位来主动调节脉管冷端流量与压力的相位差,输入压力相位由一个具有双出口的旋转阀来实现.分析表明,该调相方法可使脉管冷端流量与压力同相,从而使制冷量最大,而且相比于传统的小孔加气库型和双向进气型脉管制冷机,其制冷效率大大提高.该结构省却了体积较大的气库,结构更加紧凑. 相似文献
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A novel gas valve inlet system for gas chromatography is described. The device incorporates a capillary sample gas delivery tube containing a small orifice in its side from which sample vapor continuously flows. A precision micro stepper motor is used to translate the sample delivery tube parallel to its axis so that the orifice passes by the end of the fused silica separation column. The inlet end of the column and the sample delivery tube are housed in a pressurized injection port which also contains purge flows to vent sample between injections. Two operating modes are described. In the sweep mode, the orifice sweeps past the column end at a constant, adjustable velocity. In the park mode, the orifice is parked in front of the column end for a software selectable time. Injection sample size and bandwidth are adjustable. Bandwidths (σ) as small as a few milliseconds make the inlet suitable for high-speed gas chromatography as well as conventional GC. 相似文献
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供热空调水系统中平衡阀设计选型的模拟计算 总被引:2,自引:0,他引:2
运用图论和管网理论,介绍了使用电算程序模拟计算确定平衡阀型号的方法和步骤,此法已在实际工程设计中得到运用.实践证明该方法可以大大减少设计人员的计算工作量,提高选型的正确度. 相似文献
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After the modifications of jacket type water coolers and stacks, and the optimizations of the openings of orifice and double inlet valves, a refrigeration temperature as low as 115.4 K has been achieved by a thermoacoustically driven pulse tube refrigerator. By operating the double inlet valve of the pulse tube refrigerator, the onset temperature of the thermoacoustic system decreases from 550 to 340 °C. It provides the possibility of utilizing the low-grade heat energy. 相似文献