4 research outputs found
Effect of wingtip morphing on the roll mode of a flexible aircraft
It is well known that increasing wing span leads to improved aerodynamic performances.
To comply with airport infrastructure limits, ground folding wingtips are implemented as
a solution for wing span extension. To further justify the mechanism's weight penalty
the concept of in- ight folding is investigated here. A time domain aeroservoelastic simulation
framework is used to asses its impact on lateral ight dynamics. An established
system identi cation method, was used to derive key lateral aerodynamic derivatives and
investigate the aircraft's roll handling qualities. A range of wingtip de ections and various
ight conditions were used to generate a su ciently large database of coe cients to assess
the e ect of wingtip morphing as a function of airframe exibility and ight conditions.
Results show that overall, small changes in lateral aerodynamic derivatives are introduced
with wingtip morphing. Di erent trends in aerodynamic derivatives were identi ed as a
function of ight condition and wingtip de ection, leading to the derivation of prediction
models to replace the aerodynamic derivatives database
Method to assess lateral handling qualities of aircraft with wingtip morphing
The impact of in- ight folding wingtip on roll characteristics of aircraft has been studied
in the past. In this study, a handling qualities assessment carried out to de-risk further development
of such a device. A specialised ight simulation campaign is prepared to evaluate
the roll dynamics in di erent morphing con gurations. Various manoeuvres, including the
O set Landing Manoeuvre and herein presented Slalom and Alignment Tracking task are
used. Cooper Harper Rating scales and ight data analysis are used to collect pilot opinion
and validate pilot-in-the-loop simulation results. This example is used to demonstrate the
use of the slalom and Alignment Tracking manoeuvre for lateral dynamic assessment
Flexible high aspect ratio wing: Low cost experimental model and computational framework
Aircraft concepts of tomorrow, such as high aspect ratio wing aircraft, are far more integrated between technical disciplines and thus require multidisciplinary design approaches. Design tools able to predict associated dynamics need to be developed if such wing concepts are to be matured for use on future transport aircraft. The Cranfield University Beam Reduction and Dynamic Scaling ( BeaRDS) Programme provides a framework that scales a conceptual full size aircraft to a cantilevered wing model of wind tunnel dimensions, such that there is similitude between the static and dynamic behaviour of the model and the full size aircraft. This process of aeroelastically scaled testing combines the technical disciplines of aerodynamics, flight mechanics and structural dynamics, to provide a means by which future concept aircraft can be de-risked and explored . Data acquisition from wind tunnel testing can then be used to validate fluid-structure interaction frameworks that model the aeroelastic effect on the flight dynamics of the aircraft. This paper provides an overview of the BeaRDS methodology, and focuses on the Phase I of the programme, being the development of a reduced Cranfield A-13 aircraft cantilevered wing, to mitigate risk associated with the manufacturing and instrumentation app roach. It is shown that a low cost acquisition system of commercial Inertial Measurement Units (IMUs) can measure the response of the wing within the desired frequency range. Issues associated with the Phase I testing are discussed, and methods are proposed for the Phase II programme that allow these problems to be resolved for a larger scale flexible wing with active control surfaces
Pilot-in-the-loop flight simulation of flexible aircraft in Matlab / Simulink: Implementation and coding peculiarities
Integration of flight dynamic models, developed in the MATLAB R ā /Simulink R ā environment, with an engineering flight simulation platform allows rapid pilot-in-the-loop evaluation of new aircraft concepts at early stages of design. This paper aims to provide an overview of the integration activities needed to develop an engineering flight simulator capable of providing means to assess future concept aircraft, such as high aspect ratio wing configurations, where aeroelastic effects have a significant impact on rigid body flight dynamics. Details of the approach used to integrate an aeroelastic simulation framework with an engineering flight simulator are presented. The challenges of obtaining a real-time simulation capability and coding peculiarities of this approach are discussed. The paper expands on the discussion of integration and coding, and provides an example that demonstrates capabilities of such a framework for handling qualities assessment of a high aspect ratio wing aircraft