Numerical investigation of full scale coaxial main rotor aerodynamics in hover and vertical descent

• 作 者: Pavel V.MAKEEV Yuri M.IGNATKIN Alexander I.SHOMOV
• 机 构: Department of Helicopter Design, Moscow Aviation Institute (National Research University), Moscow 12
• 出 处: 中国航空学报（英文版）
• 发表日期: 2021年5期
• 关键词: Aerodynamic characteristics Coaxial rotor Free wake model Hover and vertical des

The original free vortex wake model was used for numerical investigation.Calculation of the aerodynamic characteristics in hover and vertical descent modes in the range of vertical descent speed of 0-30 m/s including the Vortex Ring State (VRS) area was performed.The calculations were carried out under the condition of variable blade pitch angle values providing a fixed time-average thrust value.Visualization data of free vortex wake shapes,flow structures,and velocity fields were obtained and analyzed.The time-dependences of the rotor's thrust and torque coefficients were obtained and analyzed.The obtained data allows determining the boundaries of the VRS area by various criteria such as rotor thrust and torque pulsations,growth of rotor power consumption relative to the hover,growth of rotor induced velocities relative to the hover,and growth of the required rotor blade pitch angles values.The results of the study are compared with experimental and calculated data of other authors and can significantly supplement the available results of experimental and computational studies in this area.