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Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering最新文献

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Event-triggered anti-disturbance control for aerial recovery drogue stabilization with guaranteed transient performance constraints 用于空中回收垂尾稳定的事件触发抗干扰控制,保证瞬态性能约束
Zikang Su, Mou Chen, Jia Chen, Honglun Wang
Aiming at the drogue docking control problem in aerial recovery, this paper proposes a performance event-triggered control algorithm based on disturbance observer to stabilize the flexibly towed aerial recovery drogue subject to the unknown airflows, cable towing tensions, limited computation capacity, and actuating power resources with guaranteed transient performance. Firstly, the control-oriented 6 degrees of freedom (DOF) affine nonlinear dynamics of the flexible cable-towed drogue are formulated. Then, the event-triggered extended state observers (ETESO) are established for the trajectory and attitude subsystems by utilizing intermittently measured state, to accurately estimate the lumped disturbances caused by the unmeasurable cable tension and unknown airflow disturbance while reducing the computation cost from the sensor to the observer. Moreover, to constrain the trajectory tracking error within the guaranteed transient performance constraint with any small overshoot, an ETESO-based event-triggered control algorithm for drogue was established to ensure the specified transient performance; finally, the closed-loop stability is discussed using Lyapunov analysis. The simulation results confirmed that this method can not only constrain the drogue within the expected small error range but also effectively reduce computational costs and resource occupation, with the best control effect.
针对高空回收中的垂尾对接控制问题,本文提出了一种基于扰动观测器的性能事件触发控制算法,以在保证瞬态性能的前提下稳定未知气流、缆索牵引张力、有限计算能力和动力资源条件下的柔性牵引高空回收垂尾。首先,提出了面向控制的柔性缆索牵引垂体的 6 自由度(DOF)仿射非线性动力学。然后,利用间歇测量状态为轨迹和姿态子系统建立了事件触发扩展状态观测器(ETESO),以精确估计不可测量的缆索张力和未知气流干扰所造成的块状干扰,同时降低从传感器到观测器的计算成本。此外,为了将轨迹跟踪误差控制在保证的瞬态性能约束范围内,同时不出现任何小的过冲,建立了一种基于 ETESO 的事件触发式垂尾控制算法,以确保指定的瞬态性能;最后,利用 Lyapunov 分析讨论了闭环稳定性。仿真结果证实,该方法不仅能将垂尾约束在预期的小误差范围内,还能有效降低计算成本和资源占用,控制效果最佳。
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引用次数: 0
An optimization method of electrostatic sensor array based on Kriging surrogate model and improved non-dominated sorting genetic algorithm with elite strategy algorithm 基于克里金代用模型和改进的非支配排序遗传算法与精英策略算法的静电传感器阵列优化方法
Zhirong Zhong, Heng Jiang, Hongfu Zuo
Array-type electrostatic monitoring is gradually becoming an effective tool for aero-engine fault diagnosis. In this paper, we innovatively apply the surrogate optimization method to the optimization of the sensor array structure in order to meet the need of improving the particle information recognition capability of the electrostatic sensor array (ESA). A structure optimization method of ESA based on the Kriging surrogate model and improved NSGA-II algorithm is proposed. In this paper, a finite element simulation model of ESA is established, and the array optimization problem is abstracted as the solution of a mixed-integer optimization problem. This paper reduces the large-scale numerical simulations in the full-variable space with the help of the Kriging surrogate model. In addition, an improved NSGA-II algorithm for mixed-integer optimization is proposed. The simulation experiment verified that the average absolute error of the sensor before and after optimization for the identification of particle position and charge quantity was reduced by 69.88% and 49.68%, respectively. The array structure optimization method proposed in this paper facilitates the acceleration of the design process of electrostatic sensors and provides a scientific design method for their specific design for airborne application.
阵列式静电监测逐渐成为航空发动机故障诊断的有效工具。本文针对提高静电传感器阵列(ESA)粒子信息识别能力的需要,创新性地将代理优化方法应用于传感器阵列结构的优化。本文提出了一种基于 Kriging 代理模型和改进的 NSGA-II 算法的静电传感器阵列结构优化方法。本文建立了静电传感器阵列的有限元仿真模型,并将阵列优化问题抽象为混合整数优化问题的求解。本文借助 Kriging 代理模型,减少了全变量空间的大规模数值模拟。此外,还提出了一种用于混合整数优化的改进型 NSGA-II 算法。仿真实验证明,优化前后传感器对粒子位置和电荷量识别的平均绝对误差分别降低了 69.88% 和 49.68%。本文提出的阵列结构优化方法有助于加速静电传感器的设计过程,并为其在机载应用中的具体设计提供了科学的设计方法。
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引用次数: 0
Proof of concept study on a self-driven pulsed jet on a compressor stator blade by numerical simulation 通过数值模拟对压缩机定子叶片上的自驱动脉冲射流进行概念验证研究
Weiyu Lu, Qiulin Deng, Yanmei Jiao
This study presents a new concept of self-driven pulsed jet flow control on a compressor stator blade. This passive unsteady flow control method has the advantage that neither external flow nor electrical source is needed. This study’s preliminary proof-of-concept study on a low-speed compressor stator blade is performed using numerical simulation. When the pulsed jet frequency is 100 Hz, the optimum control performance and control efficiency are reached, and the total pressure loss coefficient is reduced by 8.9%. As the valve’s rotational speed increases, the pulsed jet’s momentum coefficient decreases gradually. The analysis of the unsteady characteristics of the self-driven pulsed jet shows that the jet velocity is close to a periodic square wave signal, and the typical reduced jet velocity ranges from approximately 0.15 to 0.8. Moreover, the time-averaged driving torque on the valve depends on the rotational speed and is relevant to the self-starting and self-driven characteristics of this passive flow control method. Under different bearing resistance torque, the self-driven valve behaves differently in three cases that can self-start and be self-driven, cannot self-start but can be self-driven, and cannot self-start nor be self-driven.
本研究提出了在压缩机定子叶片上进行自驱动脉冲喷流控制的新概念。这种被动式非稳态流量控制方法的优点是不需要外部流量或电源。本研究通过数值模拟对低速压缩机定子叶片进行了初步概念验证研究。当脉冲喷射频率为 100 Hz 时,控制性能和控制效率达到最佳,总压力损失系数降低了 8.9%。随着阀门转速的增加,脉冲射流的动量系数逐渐减小。自驱动脉冲射流的非稳态特性分析表明,射流速度接近于周期性方波信号,典型的射流速度降低值约为 0.15 至 0.8。此外,阀门上的时均驱动扭矩取决于转速,与这种被动流量控制方法的自启动和自驱动特性有关。在不同的轴承阻力矩下,自驱动阀门在三种情况下表现不同,即可以自启动和自驱动、不能自启动但可以自驱动、不能自启动也不能自驱动。
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引用次数: 0
Numerical study on interference effects of the nacelle position on aerodynamic characteristics and nacelle intake performances 关于短舱位置对气动特性和短舱进气性能的干扰效应的数值研究
Yihua Cao, Yihao Qin, Maosheng Wang
Insight into the interference effects of the nacelle position can be used to provide some guidance for achieving better aircraft performance in the preliminary design of modern civil aircraft. This paper investigates the through-flow nacelle position effects on aircraft aerodynamic characteristics and nacelle intake performances through numerical simulation. The Common Research Model with different nacelle-pylon installation positions is analyzed and all the five nacelle installation parameters, including spanwise position, penetration, gully depth, pitch angle, and toe angle, are systematically studied. Qualitative and quantitative comparisons between different configurations are conducted and the sensitivity of drag, lift distribution, total pressure recovery, and airflow distortion to nacelle position is obtained. The mechanism of interference effects is also explored. These derived insights can provide some guidance for determining the nacelle position and reduce the cost of subsequent wind tunnel test.
在现代民用飞机的初步设计中,洞察短舱位置的干扰效应可以为实现更好的飞机性能提供一些指导。本文通过数值模拟研究了通流短舱位置对飞机气动特性和短舱进气性能的影响。分析了不同短舱-塔架安装位置的通用研究模型,并系统地研究了短舱安装的所有五个参数,包括跨距位置、贯通度、沟槽深度、俯仰角和趾角。对不同配置进行了定性和定量比较,得出了阻力、升力分布、总压恢复和气流扭曲对短舱位置的敏感性。此外,还探讨了干扰效应的机理。这些结论可为确定短舱位置提供一些指导,并降低后续风洞试验的成本。
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引用次数: 0
Study of the influence of multiple factors on the boundary layer of a high-lift LPT with the RBF-GA method 用 RBF-GA 方法研究多因素对高扬程 LPT 边界层的影响
Shuang Sun, Zhen Huang, Jinhui Kang, Xiaopeng Sun, Boyu Kuang, Lehan Lu
In a high-altitude cruising state, boundary layer separation exists in high-lift low-pressure turbines, and inflow conditions corresponding to different blade designs can directly affect the working efficiency of low-pressure turbines. In particular, the reduced frequency of wake and free-stream turbulence intensity in an inlet flow can greatly influence boundary layer separation and transition development. In this paper, the influence of different inflow turbulence intensities and reduced wake frequencies on the development of suction surface boundary layers in high-lift low-pressure turbines under the influence of upstream wakes is studied by numerical simulations and experiments. Due to the combination of inflow free-stream turbulence intensity and reduced wake frequency, many inflow conditions can be chosen in the design process, and the unsteady influence of upstream wakes complicates the boundary layer flow. In this paper, an RBF (radial basis function)-GA (genetic algorithm) machine learning method is used to explore the optimal inlet conditions corresponding to the minimum profile loss of the Pak-B profile. The search region of the free-stream turbulence intensity is 2%–4%, and the reduced frequency of the wake is changed by changing the flow coefficient, whose variation range is 0.7–1.3. It is found that the RBF-GA machine learning method can attain an inflow condition with a lower profile loss while using the same amount of computation and effort.
在高空巡航状态下,高扬程低压涡轮机存在边界层分离现象,不同叶片设计所对应的进气条件会直接影响低压涡轮机的工作效率。尤其是进气流中尾流频率的降低和自由流湍流强度的降低会极大地影响边界层的分离和过渡发展。本文通过数值模拟和实验研究了在上游湍流的影响下,不同的入流湍流强度和降低的唤醒频率对大扬程低压涡轮机吸气面边界层发展的影响。由于流入自由流湍流强度和降低唤醒频率的组合,在设计过程中可以选择多种流入条件,而上游唤醒的不稳定影响使边界层流动变得复杂。本文采用 RBF(径向基函数)-GA(遗传算法)机器学习方法,探索与 Pak-B 剖面损失最小相对应的最佳入口条件。自由流湍流强度的搜索区域为 2%-4%,通过改变流量系数来改变唤醒的降低频率,其变化范围为 0.7-1.3。研究发现,RBF-GA 机器学习方法可以在使用相同计算量和工作量的情况下,获得具有较低剖面损失的流入条件。
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引用次数: 0
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Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering
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