Scholarlink

<p>The U.S. Army and NASA conducted a second wind tunnel test of the TiltRotor Aeroelastic Stability Testbed (TRAST) in the Transonic Dynamics Tunnel to investigate tiltrotor whirl-flutter stability. This study focused on the impact of rotor blade stiffness and pitch–flap coupling on system stability. TRAST, a dynamically scaled semi-span model representative of the XV-15, was tested with two blade sets. One set was fabricated with fiberglass and the other stiffer blade set was fabricated with carbon fiber, specifically increasing the lag frequency. Wind tunnel experiments and analytical predictions using CAMRAD II and RCAS were compared to evaluate stability trends. Results highlight that blade flexibility plays a critical role in whirl-flutter behavior, with the fiberglass blades exhibiting a stabilizing effect at higher speeds due to rotor dynamics coupling with the airframe. Two distinct instability mechanisms were observed and defined: Tiltrotor whirl-flutter, driven primarily by gimbal and airframe dynamics, and Proprotor whirl-flutter, which includes additional coupling with blade flexibility. Importantly, this test marks the first time a single wind tunnel campaign has demonstrated distinct stability boundaries for two different blade sets, providing a direct experimental comparison of their effects on whirl-flutter.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Experimental and analytical comparison of stiff and flexible rotor blades for whirl-flutter stability

  • 期刊论文

  • 发表日期：

    2025年12月10日

查看全文
  • Andrew R. Kreshock,
  • Robert P. Thornburgh,
  • Hao Kang,
  • Hyeonsoo Yeo

摘要

The U.S. Army and NASA conducted a second wind tunnel test of the TiltRotor Aeroelastic Stability Testbed (TRAST) in the Transonic Dynamics Tunnel to investigate tiltrotor whirl-flutter stability. This study focused on the impact of rotor blade stiffness and pitch–flap coupling on system stability. TRAST, a dynamically scaled semi-span model representative of the XV-15, was tested with two blade sets. One set was fabricated with fiberglass and the other stiffer blade set was fabricated with carbon fiber, specifically increasing the lag frequency. Wind tunnel experiments and analytical predictions using CAMRAD II and RCAS were compared to evaluate stability trends. Results highlight that blade flexibility plays a critical role in whirl-flutter behavior, with the fiberglass blades exhibiting a stabilizing effect at higher speeds due to rotor dynamics coupling with the airframe. Two distinct instability mechanisms were observed and defined: Tiltrotor whirl-flutter, driven primarily by gimbal and airframe dynamics, and Proprotor whirl-flutter, which includes additional coupling with blade flexibility. Importantly, this test marks the first time a single wind tunnel campaign has demonstrated distinct stability boundaries for two different blade sets, providing a direct experimental comparison of their effects on whirl-flutter.