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首页> 外文期刊>Journal of the American Helicopter Society >Using Control Redundancy for Power and Vibration Reduction on a Coaxial Rotor Helicopter at High Speeds
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Using Control Redundancy for Power and Vibration Reduction on a Coaxial Rotor Helicopter at High Speeds

机译：使用控制冗余高速降低同轴旋翼直升机的功率和减振

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This study uses the Rotorcraft Comprehensive Analysis System (RCAS) to examine the effect of control redundancy on power and vibratory hub loads of a lift-offset coaxial rotor helicopter operating at 230 kt cruise speed. An aircraft nose-up pitch attitude of 3 degrees resulted in very low main rotor power (less than 10% of the total power), with the majority of the power consumption attributed to an efficient axial propeller. At this 3 degrees pitch attitude, the rotor speed and differential lateral pitch, which are redundant controls, were parametrically varied, and low power (LP) and low vibration (LV) states identified. The LP state (80% Nr and 3 degrees differential lateral) required 3.5% lower power than the LV state (90% Nr and 0 degrees differential lateral), but the latter had substantially lower 3/rev vibratory hub loads. The lower power in the LP state is primarily due to reduced main rotor power on account of smaller drag on the advancing blade tip at lower rotor speeds. The rotor drag is comparable for the two states, but the LV state has larger drag contributions from the advancing side, whereas the LP state has larger contributions from the reverse flow region (accounting for 14% of the total rotor drag) due to higher pitch on the retreating side and larger reverse flow velocities. Even so, the rotor drag accounts for under 30% of the total propulsor thrust requirement, with the fuselage (and hub) drag being the dominant component. Rotor L/De values for the LP and LV states were 12.3 and 11.3, respectively.
机译：这项研究使用旋翼飞机综合分析系统（RCAS）来研究控制冗余对以230 kt巡航速度运行的升举偏置同轴旋翼直升机的功率和振动轮毂负载的影响。飞机俯仰姿态为3度时，主旋翼功率非常低（不到总功率的10％），大部分功率消耗归因于高效的轴向螺旋桨。在此3度的俯仰姿态下，参数化改变了冗余控制的转子速度和横向横向螺距，并确定了低功率（LP）和低振动（LV）状态。 LP状态（80％Nr和3度差分横向）比LV状态（90％Nr和0度差分横向）需要低3.5％的功率，但后者的3 / rev振动轮毂负载要低得多。在LP状态下，较低的功率主要是由于在较低的转子速度下，前进叶片尖端上的阻力较小，因此主转子功率降低了。对于这两种状态，转子阻力是可比较的，但是由于较高的螺距，LV状态在前进侧具有较大的阻力贡献，而LP状态在逆流区域具有较大的贡献（占总转子阻力的14％）。在后退侧和更大的逆流速度。即便如此，转子阻力仍占推进器总推力需求的30％以下，而机身（和轮毂）阻力是主要组成部分。 LP和LV状态的转子L / De值分别为12.3和11.3。

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