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Helicopter rolling response forecasting method with flexible airbag under irregular waves

A flexible airbag, helicopter technology, applied in instruments, electrical digital data processing, geometric CAD, etc., can solve problems such as long calculation time

Active Publication Date: 2020-01-21
NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
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  • Abstract
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  • Application Information

AI Technical Summary

Problems solved by technology

[0004] This application provides a method for predicting the roll response of a helicopter with a flexible airbag under irregular waves to solve the problem that the calculation time of the existing method for calculating the roll response of a helicopter with a flexible airbag is too long

Method used

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  • Helicopter rolling response forecasting method with flexible airbag under irregular waves
  • Helicopter rolling response forecasting method with flexible airbag under irregular waves
  • Helicopter rolling response forecasting method with flexible airbag under irregular waves

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Embodiment Construction

[0039] The following will clearly and completely describe the technical solutions in the embodiments with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only some of the embodiments of the application, not all of them. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of this application.

[0040] A method for predicting the roll response of a helicopter with a flexible airbag under irregular waves, including:

[0041] (1) For a certain type of helicopter with a flexible airbag, divide the finite element mesh.

[0042] refer to figure 1 , a certain type of helicopter with flexible airbags is divided into finite element meshes by using Hypermesh software.

[0043] Hypermesh software is a product of Altair in the United States. It is a world-leading and powerful CAE application software p...

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Abstract

The invention discloses a helicopter rolling response forecasting method with flexible airbags under irregular waves, and belongs to the field of helicopter forced landing overwater floating and overturning. The method comprises: dividing finite element grids for a certain type of helicopter with a flexible air bag; importing the finite element grids into finite element calculation software to obtain a helicopter transverse static stability curve and helicopter rolling response curves under a calm water surface and two regular waves; obtaining a damping term in the rolling kinetic equation according to the damping formula considering the nonlinear term and the helicopter rolling response curve under the quiet water surface; through Matlab programming, obtaining wave surface equations underregular waves and irregular waves; and substituting the wave surface equation under the irregular wave and the helicopter transverse static stability curve into a rolling kinetic equation to obtain ahelicopter rolling response curve under the irregular wave. According to the method, the rolling response condition of the helicopter under the irregular waves can be forecasted only through simple programming and helicopter fluid-solid coupling simulation calculation under a plurality of simple water surface conditions.

Description

technical field [0001] The present application relates to the field of floating and overturning of helicopter forced landing, in particular to a method for predicting roll response of a helicopter with a flexible airbag under irregular waves. Background technique [0002] At present, there are relatively few researches on the floating of helicopters at home and abroad, and most of the numerical simulation calculations are carried out around the method of equating the helicopter with the floating system to a single rigid body. But in fact, depending on the flotation system, the impact of the rigidity and flexibility of the airbag and the connecting belt is huge. After calculation, it is found that for the lateral static stability of a certain type of helicopter, when the flexibility of the airbag and the connecting belt is not considered , the maximum error between the calculation of the static stability curve and the test is as high as 83.3%, but when considering the flexibi...

Claims

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Application Information

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IPC IPC(8): G06F30/15G06F30/20G06F119/14
CPCY02T90/00
Inventor 李乐张红英
Owner NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
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