Abstract

In the framework of fast rotorcraft, smoothness and flushness of external aerodynamic surfaces present challenges for high-speed conditions, where aerodynamics is the driver of helicopter performance. For AIRBUS-RACER helicopter the main landing gear trap doors are parts of the lower wing skins (in retracted configuration) affecting helicopter performance by minimizing the drag. Flushness requirements must not be in contrast with the functionally of the Landing gear system that must open and close the doors during the landing gear retraction-extension phases at moderately low velocity. To manage these goals, a novel design logic has been identified to support the trap doors development phase. The identified way to proceed needs of relevant numerical method and tool as well. This method is aimed at identifying the main landing gear composite compartment doors in pre-shaped configuration to match the smoothness and door-stopper engagements over each aerodynamic conditions. The authors propose a detailed non-linear Finite Element method, based on MSC Nastran (MSC Software, Newport Beach, US) SOL-400 solver in which the structure is modelled with deformable contact bodies in a multiple load step sequence, open door condition and pre-shaped, deformed under actuator pre-load, under flight load conditions. The method includes the entire pre-stressed field due to the preload and the actual door stiffness, considering the achieved large displacement to verify the most representative strain field during loads application. The paper defines a robust methodology to predict the deformation and ensure the most appropriate door “pre-bow” and pre-load, in order to achieve the desiderated structural shape that matches aerodynamic requirements. The main result is the identification of a pre-shaped doors configuration for the Airbus RACER Fast Rotorcraft.

Highlights

  • In the framework of Clean Sky 2 the project ANGELA is aimed at developing the landing gear system of the Airbus Helicopters Rapid and cost-efficient rotorcraft (RACER) flight prototype (Figure 1)

  • A deviation exists between the deformed Outer Mould Line (OML) surfaces with respect to the

  • Blue is within flushness requirements). This developed method shows a robust approach to numerically calculating the geometrical This developed method shows a robust approach to numerically calculating the geometrical manufacturing shape of the Main Landing Gear (MLG) door for high speed compound rotorcraft

Read more

Summary

Introduction

In the framework of Clean Sky 2 the project ANGELA is aimed at developing the landing gear system of the Airbus Helicopters RACER flight prototype (Figure 1). The development of the compartment doors are part of ANGELA and RACER program. Aerospace 2020, 7, 88; doi:10.3390/aerospace7070088 www.mdpi.com/journal/aerospace 20161). The The landing gear system ofofthe wheeledtype type and oleo-pneumatic landing gear system theRACER. RACER is is aa tricycle tricycle wheeled and oleo-pneumatic shockshock absorber landing gear system. It is composed by the following systems/sub-systems/equipment shown absorber landing gear system.

Methods
Results
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call