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Flight dynamics simulation modeling for hingeless and bearingless rotor helicopters.

机译：无铰链和无轴承旋翼直升机的飞行动力学仿真建模。

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摘要

A mathematical model is described for an articulated, hingeless or bearingless rotor helicopter that is suitable for flight dynamics analysis. The mathematical model is formulated to provide a non-linear state-space representation of the helicopter dynamics. The model may be configured to incorporate either a blade element level unsteady aerodynamics analysis, based on a state-space representation of unsteady aerodynamics, or a finite state wake dynamic inflow model. The main rotor model is based on a finite element analysis allowing moderately large elastic deflections for coupled blade flap, lag, torsion and axial deformations. The formulation of the coupled rotor and fuselage equations enables the use of common solution techniques for trim and linearization in arbitrary steady climbing or descending turning flight, as well as free flight response calculations. An innovative trim algorithm is presented which reduces the otherwise prohibitive computational requirements associated with the large increase in total number of states when the state-space unsteady aerodynamics model is included.;The mathematical model for an articulated configuration is validated by comparing model responses against flight test data measured on an articulated rotor aircraft. Comparisons are made for three aerodynamic model configurations. These are quasi-steady airfoil aerodynamics in conjunction with a three state dynamic inflow model, quasi-steady airfoil aerodynamics in conjunction with a 21 state finite state wake model and unsteady airfoil aerodynamics in conjunction with a three state dynamic inflow model. Trim control positions, frequency response and free flight time history response results have been generated in each case. Results are presented for hover and steady level forward flight at 80 kts and 120 kts.;For the bearingless main rotor configuration a comparison is made against results generated by an aeroelastic rotor code. A comparison of frequency response results for a range of retained main rotor mode shapes is made for hover flight condition as well as steady level forward flight at advance ratios of 0.15 and 0.30. An analysis of frequency response for this configuration in turning flight is made together with a comparison of frequency response behaviour for varying flexbeam stiffness.
机译：描述了适用于飞行动力学分析的铰接，无铰链或无轴承旋翼直升机的数学模型。制定了数学模型，以提供直升机动力学的非线性状态空间表示。该模型可以配置为结合基于非稳态空气动力学的状态空间表示的叶片元件级非稳态空气动力学分析或有限状态尾流动态流入模型。主转子模型基于有限元分析，允许适度较大的弹性挠度，以用于耦合叶片的襟翼，滞后，扭转和轴向变形。旋翼和机身方程的耦合公式使得可以在任意稳定爬升或下降转弯飞行以及自由飞行响应计算中使用通用的求解技术来进行纵倾和线性化。提出了一种创新的微调算法，该算法可在包含状态空间非定常空气动力学模型的情况下减少与状态总数大幅度增加相关的其他过高的计算需求。在铰接旋翼飞机上测得的测试数据。对三种空气动力学模型配置进行了比较。这些是结合三态动态流入模型的准稳态翼型空气动力学，结合21态有限状态尾流模型的准稳态翼型空气动力学以及结合三态动态流入模型的非稳态翼型空气动力学。在每种情况下，都会生成微调控制位置，频率响应和自由飞行时间历史响应结果。给出了在80 kts和120 kts时悬停和稳定水平向前飞行的结果。对于无轴承主旋翼配置，将其与气动弹性旋翼代码生成的结果进行了比较。对于悬停飞行条件以及稳定水平的前向飞行（提前比为0.15和0.30），比较了一系列保留的主旋翼模式形状的频率响应结果。分析了这种配置在转弯飞行中的频率响应，并比较了不同挠曲梁刚度的频率响应行为。

著录项

  • 作者

    Turnour, Stephen Richard.;

  • 作者单位

    University of Maryland, College Park.;

  • 授予单位 University of Maryland, College Park.;
  • 学科 Engineering Aerospace.;Engineering Mechanical.
  • 学位 Ph.D.
  • 年度 1996
  • 页码 367 p.
  • 总页数 367
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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