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微型涡轮发动机燃油闭环控制起动方法 总被引:3,自引:2,他引:1
采用微压差方法进行燃油流量测量,达到低压损、高精度和快速响应的目的.设计了孔板式计量段,对不同节流孔径的计量段进行了标定试验.试验结果表明:在设定的测量范围内,节流孔两侧压差的平方根与流量成线性关系,与理论分析结果一致.在此基础上,研究微型涡轮发动机起动过程供油流量闭环控制问题.设计了单神经元PID(比例-积分-微分)控制器,对燃油流量进行了闭环控制试验.与开环控制方法相比,新的控制方法动态性能好,调节精度高.最后,采用单神经元PID控制器进行了微型涡轮发动机燃油闭环控制起动试验,显著提高了起动过程的快速性与可靠性. 相似文献
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为了开发数控燃油计量装置独立仿真平台,利用AMESet建立了基于C代码的步进电机部件模型;对建立的步进电机模型进行仿真,获得了其转角随输入脉冲的关系。建立了由计量活门、等压差活门、增压活门等组成的燃油计量装置机械液压组件AMESim模型,将开发的步进电机模型与计量装置各液压组件模型联结,实现了步进电机驱动的数控燃油计量装置面向对象的建模。仿真结果表明:在正常工作范围内,仿真结果与设计参考偏差在5%以内,所开发的AMESim模型能满足该数控计量装置的稳态和动态特性的研究要求。 相似文献
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为了准确测试航空发动机燃油计量组件的性能状态,对其性能试验的控制系统进行研究。基于燃油计量组件的结构、工作原理以及试验要求设计液压控制系统,采用由伺服电机、丝杠和光栅传感器组成的位移伺服控制系统实现计量组件阀芯位移的精确控制,提出“泵阀复合控制+进、出口压力协调控制”的控制策略,以实现计量组件出口压力和进、出口压差的精确控制。结果表明:该燃油计量组件阀芯位移控制精度可达到±0.001 mm,计量组件后压力及前后压差的控制精度均可达到±0.002 MPa,该燃油计量组件性能试验控制系统可以满足性能试验的需求。 相似文献
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《中国航空学报》2020,33(6):1812-1823
The temperature-induced variation in operating force of flow control valves may result in performance degradation or even jam faults of fuel metering unit (FMU), which significantly affects the safety of aircrafts. In this work, an analytical modeling approach of temperature-sensitive operating-force of servo valve is proposed to investigate the temperature characteristics in varying temperature conditions. Considering the temperature effects, a new extended model of flow force is built and an analytical model of valve friction is also derived theoretically based on the dynamic clearance induced by thermal effects. The extremum condition of friction is obtained to analyze the characteristic-temperature points where jam faults occur easily. The numerical results show that flow force increases firstly and then decreases as temperature increases under a constant valve opening. The maximum friction of flow servo valve can be uniquely determined when the structural parameters and ambient temperature are given. The worst situation just happens at the characteristic-temperature points, which are linearly related to the axial temperature gradients of valve spool. Such evaluations may give an explanation for the temperature-induced jam faults of vulnerable valves and provide a reference for designers to determine a suitable working-temperature range of valves in practice. 相似文献
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为获得加力燃油系统数字化仿真与性能验证平台,采用功能划分的方法分析了典型计量装置的功能模块,确定了伺服阀-随动活塞、计量活门-等压差活门是决定计量装置动态特性的主要组成部分,对其进行了数学建模。鉴于获得的数学模型描述系统特性时缺乏相关元件特性参数的设计依据,建立了由计量活门、等压差活门、电液伺服单元等组成计量装置的AMESim模型,计算主要结构参数后仿真分析了其稳态和动态特性。结果表明:基于控制系统构成的加力燃油计量装置功能划分与数学建模可为仿真研究与参数设计提供指导,AMESim可用于动态过程仿真与性能预测。 相似文献
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考虑某型涡轴发动机燃油流量调节器通道截面的局部能量损失,推导出流经计量油针的燃油流量方程,在此基础上详细分析等压差活门的功用、结构组成及其工作原理,以连续方程和力平衡方程为基础,采用线性化处理方法,建立等压差活门的数学模型。通过分析等压差活门系统结构,得到等压差活门系统的传递函数,进而对其稳定性进行分析,计算单位阶跃输入的稳态误差。结果表明:以流量方程和力平衡方程为基础建立等压差活门数学模型的方法可行,分析出等压差活门稳定工作条件和稳态误差的主要影响因素,并且为燃油调节器数学模型的建立以及仿真计算奠定了基础。 相似文献
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为研究双自由度(2D)压力伺服阀工作时的气穴现象对阀芯稳定性的影响,利用AMESim中的基本库和HCD库建立2D压力伺服阀各组件仿真模型。理论分析得出气穴现象会降低阀体中含气油液的有效体积弹性模量,得出考虑气穴影响的阀芯稳定性条件。仿真结果表明气穴现象会导致主阀芯到达稳定位置后出现振荡现象,影响主阀芯的穿越频率从21 Hz降低至6 Hz,限制主阀芯的频宽,适当增加主阀芯阻尼比能提高主阀芯工作稳定性。提出一种新型阻尼活塞结构,建立模型分析得出其能在不影响伺服阀频响、阀芯位移和抗污染能力情况下提高主阀芯阻尼比以提高阀芯工作稳定性,并且设计实验进行验证。实验结果表明,应用阻尼活塞将2D压力伺服阀压力输出波动从9%降低至2%,能够提高飞行器制动时刹车阀工作稳定性。 相似文献
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Electrochemical drilling(ECD) provides an alternative technique for drilling multiple small holes in difficult-to-machine materials in numerous industrial applications such as for aeroengines. The value and fluctuation of electrolyte flowrate can seriously affect the machining stability and hole quality in ECD. In particular, when drilling multiple holes, the distribution and fluctuations of the electrolyte flowrate in each channel could influence the uniformity of the electrolyte flowrate among... 相似文献
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等增益比燃油计量活门型孔设计计算 总被引:1,自引:0,他引:1
为解决普通方形、圆形、三角形等燃油计量活门型孔流量增益比变化大的问题,提出了一种等流量增益比的燃油计量活门型孔设计思路。通过理论计算得到了等增益比活门型孔曲线函数的基本形式和详细设计计算方法,并进行了举例计算。流量增益比与计量活门开度扰动量的比值为定值,两者呈正比关系,活门开度扰动量越小,流量增益比越小,即计量精度越高。与方形型孔进行了对比分析,详细说明了等增益比型孔在小流量状态下,增益小抗干扰能力强的优点,并且通过组合型孔设计,避免了等增益比活门型孔大流量状态下的增益过大问题。 相似文献
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针对燃油计量活门特殊型孔的几何型面问题,提出了1种分段分析的设计方法。在已知燃油流量和计量活门位移函数关系的条件下,根据随动活塞和燃油流量的函数关系,利用分段型面设计法进行正向设计,在已知计量活门几何型面的条件下,确定开度与随动活塞位移之间的函数关系,进行反向设计用于计算仿真。结果表明,在计量活门工作范围内,正向设计计算结果与实际数据的最大相对误差小于0.5%,证明正向设计方法具有很高的准确性;通过1组实例对正反向设计进行了相互验证,证明反向设计方法具有工程实用性。 相似文献
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基于钇稳定二氧化锆(Yttria-stabilized Zirconia,YSZ)的阻温特性,设计了以YSZ热敏电阻为感受元件的火焰传感器,以传感器热敏电流信号表征火焰状态。采用伏安法,测量了YSZ热敏电阻在673K~1523K温度下的阻值,验证了YSZ阻值与温度的倒数呈指数关系。在Tirril喷灯点火、熄火试验中,研究了激励电压(3V~15V)、火焰温度(720K~1480K)和燃气流量(60L/h~150L/h)对传感器阶跃响应特性的影响。结果表明:热敏电流与激励电压呈正比,随火焰温度的升高而增大;点火响应时间随火焰温度、燃气流量的升高而减小;熄火响应时间基本不受火焰温度与燃气流量的影响。YSZ传感器能够对火焰产生正确响应,并且信号稳定、幅值强烈。 相似文献
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Design and optimization of a novel electrically controlled high pressure fuel injection system for heavy fuel aircraft piston engine 总被引:1,自引:1,他引:0
The heavy fuel compression ignition engines are widely equipped as aircraft piston engines. The fuel injection system is one of the key technologies that determines the performance of engine. One of the main challenges is to precisely control the injected fuel quantity and flow rate in the presence of pressure fluctuation. This challenge is even more serious for heavy fuel. An original design for electrically controlled high pressure fuel injection system called Multi-Pumppressure-reservoirs fuel injection System(MPS) was demonstrated to reduce the pressure fluctuation and help keep injection stable. MPS was compared with an ordinary high pressure Common Rail fuel injection System(CRS). This work established one-dimensional AMESim and mathematical models for both CRS and MPS to study the effect of different structures and geometric parameters on the pressure fluctuations. The calculations show that the average fuel pressure fluctuation of MPS can be reduced by 57% for the crankshaft speed of 1900 r/min, and the pressure fluctuation before injection reduced by 100%. It is concluded that the pressure performance of MPS is less sensitive to pressure reservoir volume than that of CRS, and there is an opportunity for further volume reduction. 相似文献
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为了在主燃油计量活门位移传感器出现故障时仍能实现航空发动机全包线范围内的转速自适应控制,根据航空发动机转速自适应控制原理提出了一种基于零极点配置原理的容错控制方法,根据高压转子转速控制计划与实测转速之间的误差对主燃油控制电液伺服阀电流进行闭环运算,并运用零极点配置原理将控制参数与转速自适应控制相融合,参数在全包线范围内随发动机状态变化进行自适应调整,通过半物理模拟试验对该容错控制方法进行了验证。结果表明:该容错控制方法能够在全包线范围内保证数字电子控制系统稳定工作,并具有较好的稳态和动态性能,发动机高压转子转速稳态波动量在±0.15%以内,超调量和下降量分别在0.63%和0.61%以下,而且容错控制方法实施方便、自适应性强,对提高航空发动机数字电子控制系统的工作可靠性具有重要作用。 相似文献
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《中国航空学报》2021,34(5):205-213
The Electromechanical Oxygen Regulator (EMOR) is a new type of aviator oxygen equipment. Positive pressure refers to the pressure difference between the breath pressure and the ambient pressure during pressurized oxygen supply. The phenomenon of positive pressure fluctuation was believed to reduce the system performance. The current open-loop control method cannot solve this problem. In this paper, the mathematical model was established and main factors were analyzed. By combining experimental research and simulation calculation, it was determined that pressure fluctuation was caused by inlet pressure and diaphragm deformation together. With the increase of pulmonary ventilation volume, the influence of inlet pressure on fluctuation decreases gradually, while the proportion of diaphragm deformation increases rapidly. A closed-loop control strategy of Proportional Resonant with Feedforward Compensation (PRFC) was proposed to solve the problem and control parameters were obtained through co-simulation. The effectiveness of the control strategy was verified by experiments. The results show that the control strategy can enhance the anti-disturbance ability of the system and significantly reduce the pressure fluctuation range, which is beneficial to improving the overall system performance. 相似文献