Browsing by Author "Lone, Mohammad M."
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Item Open Access Closer look at the flight dynamics of wings with non-elliptic lift distributions(AIAA, 2020-01-05) Aldana, Estela Bragado; Lone, Mohammad M.Prandtl’s alternative solution for wings with minimum induced drag opens another route for improving aircraft performance especially at the conceptual design phase. In this work, the lateral-directional characteristics of such wings are studied for a glider use case from a per-spective that focuses on pro verse yaw and handling qualities. The authors propose an aileron design methodology that ensures roll authority and proverse yaw characteristics. The resultsshow that these conditions cannot be satisfied by a conventional Elliptic configuration, whereaswings with non-elliptic distributions provide several solutions. Non-linear flight dynamic mod-els of the configurations that provided maximum proverse yaw were assessed in an engineering simulator and compared against the baseline Elliptic case. Proverse yaw was observed in thesimulation data and pilot feedback indicated improved handling qualities in the non-elliptic cases. However, the inherent directional instability combined with other lateral-directional coupling effects masked the observations from the pilot’s perspective.Item Open Access Development of a pilot model suitable for the simulation of large aircraft(Optimage Ltd. on behalf of the International Council of the Aeronautical Sciences, 2010-09) Lone, Mohammad M.; Cooke, Alastair K.Effects of aeroservoelasticity on the manual control of large civil aircraft are investigated through a pilot modelling approach based on the modified optimal control model. A synopsis of modelling techniques is presented, followed by the description of the adopted technique. A simulation environment suitable for investigating pilot-vehicle dynamics in the longitudinal axis has been developed. The derivation of the pilot model was based on limiting the bandwidth. This approach showed that the pilot-vehicle system satisfied the crossover law between 3rad/s to 10rad/s for normal acceleration response. It was found that the pilot model and the low frequency tailplane bending mode introduced a resonant peak in the pilotvehicle frequency response that may be a cause for concern in high gain scenarios. Gust response simulations highlighted the contribution of fuselage bending mode on pilot perceived normal acceleration.Item Open Access Fast computational aeroelastic analysis of helicopter rotor blades(AIAA, 2018-01-13) Fleischmann, Dominique; Weber, Simone; Lone, Mohammad M.The use of a new aeroelastic computer framework called Flexit is described and the frame-work is used to analyse the dynamic aeroelastic behaviour of a four-bladed helicopter main rotor. Flexit implements a loose coupling between unsteady vortex lattice method (UVLM) and numerical solution of the inhomogeneous Euler-Bernoulli partial differential equation (PDE).The framework is fast because most of the intensive computational functionality is performed on GPU using NVIDIA CUDA technology, and this makes it suitable for use in the early de-sign stages. The UVLM algorithm uses a free wake model, and solution of the Euler-Bernoulli PDE is approximated using a finite difference algorithm that includes a term to take account of centrifugal forces. The results of simulations are compared with analysis performed with CFD and FSI tools.Item Open Access Flexible high aspect ratio wing: Low cost experimental model and computational framework(AIAA, 2018-01-13) Pontillo, Alessandro; Hayes, David; Dussart, Gaétan X.; Lopez Matos, Guillermo E.; Carrizales, Martin A.; Yusuf, Sezsy Y.; Lone, Mohammad M.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.Item Open Access Method to assess lateral handling qualities of aircraft with wingtip morphing(2018-01-13) Dussart, Gaétan X.; Yusuf, Sezsy Y.; Portapas, Vilius; Lopez Matos, Guillermo E.; Lone, Mohammad M.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.Item Open Access Pilot-in-the-loop flight simulation of flexible aircraft in Matlab / Simulink: Implementation and coding peculiarities(AIAA, 2018-01-13) Lopez Matos, Guillermo E.; Portapas, Vilius; Dussart, Gaétan X.; Lone, Mohammad M.; Coetzee, EtienneIntegration of flight dynamic models, developed in the MATLAB R ⃝ /Simulink R ⃝ 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.