ASSIGNMENT - DESIGN & ANALYSIS OF A HELICOPTER LANDING GEAR
From the assignment brief
You will be provided with some typical data ranges for this type of helicopter, including the mass and some of the dimensions. You will need to find any additional figures you need by research or calculations. The design criteria is deliberately open, it is up to you how many wheels you use and how you model the system in Adams/view. Simulations should be validated with hand calculations where possible.
Datarelating to naval helicopters
The ranges given are a guide - if your research uncovers something outside these ranges, it is ok to use it, just make it clear where the information has come from.
Length of helicopter body (not including rotor blades) - 12.5 to 20 meters
Width of helicopter body (not including rotor blades) -1.5 to 3.2 meters
Empty mass - 2500 to 11,000 kg
Fully loaded mass - 4500 to 15,000 kg
Ground clearance - typical ground clearances vary based on the landing gear used, you need to research this in order to justify your design for the landing gear arrangement. Your mechanism should simply be a sensible size, it does not have to perfectly mimic an existing system.
Steering- you do not need to concern yourself with the steering mechanism, which allow the craft to be manoeuvred on deck.
Retraction - you do not need to concern yourself with the retraction mechanism, which pulls the landing gear into the body of the craft when in flight.
Design and analysis of a helicopter landing gear
Brief
A landing gear is to be designed for a naval helicopter which is suitable for landing on an aircraft carrier. The motion of the aircraft carrier is an important consideration for the design. Vertical movement of the carrier due to the sea waves will cause a harder than expected landing for the pilot and has the potential to cause vibration during storage, therefore the design must allow for this to prevent damage to the helicopter. The design must also cater for diverse landing situations.
You will be provided with some typical data ranges for this type of helicopter, including the mass and some of the dimensions. You will need to find any additional figures you need by research or calculations. The design criteria is deliberately open, it is up to you how many wheels you use and how you model the system in Adams/view. Simulations should be validated with hand calculations where possible.
Tasks
This is an individual assignment which comprises of four main sections:
1) The first element is to conduct research into the geometry of a typical helicopter landing gear arrangement and design a mechanism to connect the wheels to the fuselage. You should clearly justify the elements of your design.
2) The second element of the task is to specify the springs and dampers used for your particular mechanism. The springs and dampers must allow the helicopter to be able to land on an aircraft carrier under a range of specified conditions:
a. Normal landing - Vertical descent speed of 0.6m/s, stationary deck, minimal acceleration and oscillations of the helicopter body to provide maximum comfort.
b. Hard landing - Vertical descent speed of 4m/s, stationary deck, acceleration of the helicopter body must be less than 40m/s2 to prevent damage to the helicopter.
c. Crash landing - Vertical approach speed 16m/s, stationary deck, acceleration of the helicopter body must be less than 190m/s2 to minimise injury to passengers.
3) The third element of the task is to analyse the performance of the helicopter when it is stored on the deck of the aircraft carrier. Assume that the carrier deck will move vertically is simple harmonic with an amplitude 0.1 m and a frequency 1 Hz (6.28 rad/s) in response to the ocean waves, therefore the amplitude and resonance of your mechanism in response to this must be investigated.
4) The fourth element of the task is the modelling and simulation of the landing gear using Adams/view.
There are also marks available for the production of a well presented, professional report, with suitable structure and adequate references, etc., see the marking scheme for further details.
Scope
Some tasks may be suitable for hand calculations, whilst others may be suitable for multi-body software analysis (in Adams/view). An integral part of this assignment is being able to choose the most appropriate analysis methods. You should justify your choices, and state any consequent compromises that result. You should accompany your simulations with hand calculations where possible for validation and use either MatLab or Excel to plot appropriate results graphs.
Attachment:- Assignment Files.zip