Abstract:
A rotor design of a Ram Air Turbine (RAT) for a commercial aircraft was created taking three sections with different airfoils along the blade; those sections were assessed to evaluate their performance at different critical velocities (41, 81 and 251 m/s) and choose the best profile configuration generating a new proposal to increase the glide ratio by reducing the drag, which is helpful in emergency cases. The Blade Element Momentum (BEM) theory and Computational Fluid Dynamics (CFD) were used to analyze an initial design, then validating these results with the open software QBlade. For the BEM theory a program was created for the design and performance of the RAT adding the Viterna methodology for airfoil analysis. 16 designs were proposed by strategically interchanging wing profiles in different blade sections. These designs were analyzed by CFD, using the complete rotor and the S S T k - ω turbulence model. An optimal geometry was found, presenting a significant drag reduction of 25% generating an increase in the glide ratio and improving aircraft control in addition to maintaining the power generation above the desired values; therefore, it recommends using different airfoils for each section of a RAT\'s rotor blade.
摘要:
为商用飞机创建了冲压空气涡轮机(RAT)的转子设计,该转子设计采用沿叶片具有不同翼型的三个部分;对这些部分进行了评估,以评估其在不同临界速度(41、81和251m/s)下的性能,并选择最佳的轮廓配置,从而通过减少阻力来提高滑翔比,这在紧急情况下很有帮助。叶片元素动量(BEM)理论和计算流体动力学(CFD)用于分析初始设计,然后用开放软件QBlade验证这些结果。对于BEM理论,为RAT的设计和性能创建了程序,并添加了用于翼型分析的维特纳方法。通过战略性地互换不同叶片截面的机翼轮廓,提出了16种设计。这些设计由CFD分析,使用完整的转子和SSTk-ω湍流模型。找到了一个最佳的几何形状,显着降低25%的阻力,从而增加了滑翔比,并改善了飞机的控制,除了将发电量保持在期望值之上;因此,建议对RAT转子叶片的每个部分使用不同的翼型。