A Ground Modeling Method for Coaxial Twin-rotor Helicopter

Abstract

The invention discloses a coaxial twin-rotor helicopter ground resonance modeling method, which belongs to the technical field of helicopter ground resonance modeling. Including step 1, first establish the coordinate system of each system and establish the transformation relationship between each coordinate system, describe the motion of the body and rotor blades in the established coordinate system; step 2, determine the restraint force of the landing gear on the motion of the body, and then Establish the body motion equation; step 3, mirror the lateral, roll and yaw degrees of freedom of the nonlinear motion equation of the upper rotor, and replace the distance between the hub center of the upper rotor and the center of gravity of the body with the hub center of the lower rotor The distance from the center of gravity of the fuselage to obtain the nonlinear motion equation of the lower rotor; step 4, solve the rotor motion balance point, and linearize the rotor nonlinear motion equation at the rotor motion balance point; step 5, perform multi-blade coordinate transformation, and The linearized rotor motion equation and body motion equation are assembled to obtain the ground resonance analysis model of the coaxial dual-rotor helicopter.

Description

technical field [0001] The invention belongs to the technical field of helicopter ground resonance modeling, and in particular relates to a ground modeling method for a coaxial dual-rotor helicopter. Background technique [0002] Due to the influence of its own configuration, the conventional helicopter will have the separation of the forward blade shock wave and the backward blade airflow at high speed, which makes its flight performance (maximum speed, range, and maneuverability at high speed, etc.) Large limitations, especially the limitation of the maximum speed and the surge of required power when flying at high speed will directly affect the transport capacity and economy of the helicopter. The shortcomings of helicopters such as small mission radius, short flight range, slow flight speed, and large vibration limit the scope of use of helicopters. [0003] Coaxial twin-rotor helicopters are one of the development directions of helicopters. Like single-rotor helicopter...

AI Technical Summary

Problems solved by technology

However, the difference between two rotors and one rotor is not just the difference between two and one, it may change the coupling type of the airframe and the rotor, resulting in a change in mechanism

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