23 research outputs found
Development of a pilot model suitable for the simulation of large aircraft
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
Fast computational aeroelastic analysis of helicopter rotor blades
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
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
ECOPHAGE: Combating Antimicrobial Resistance Using Bacteriophages for Eco-Sustainable Agriculture and Food Systems
The focus of this meeting was to discuss the suitability of using bacteriophages as alternative antimicrobials in the agrifood sector. Following a One Health approach, the workshop explored the possibilities of implementing phage application strategies in the agriculture, animal husbandry, aquaculture, and food production sectors. Therefore, the meeting had gathered phage researchers, representatives of the agrifood industry, and policymakers to debate the advantages and potential shortcomings of using bacteriophages as alternatives to traditional antimicrobials and chemical pesticides. Industry delegates showed the latest objectives and demands from consumers. Representatives of regulatory agencies (European Medicines Agency (EMA) and Spanish Agency of Medicines and Health Products (AEMPS)) presented an update of new regulatory aspects that will impact and support the approval and implementation of phage application strategies across the different sectors
Soybean and Sustainable Agriculture for Food Security
Global food security is under-challenged due to over increasing human population, limited cropland, and risk of climate change. Therefore, an appropriate agricultural policy framework needs to be developed for food security that should be sustainable economically and ecologically. Nitrogen (N) is a crucial element that controls the growth productivity of crop plants. N accounts for around 78 volume per cent of the atmosphere but all crop plants cannot use it directly. Agricultural land is mostly dominated by cereals (e.g. rice, wheat, maize) which have specifically high N demand as compared to food legumes. Soybean exemplifies the most significant and cultivated food legume, presently cultivated worldwide under varying climatic conditions. It plays a significant role in global food security as well as agricultural sustainability due to a high seed protein and oil concentration, and low reliance on N fertilization. Soybean enriches soil health by fixing atmospheric N through biological nitrogen fixation (BNF), the most productive and economical system for N fixation and crop production, associated with more intensive production systems. However, the efficiency of BNF depends on several factors. This study is focused to develop more reliable guidelines for managing BNF by using the potential of natural agro-ecosystems
Guilandina bonduc L. Possesses Antioxidant Activity and Precludes Ferric Nitrilotriacetate (Fe-NTA) Induced Renal Toxicity and Tumor Promotion Response
Rapid hydrothermal synthesis of mesoporous NiS2 and NiSe2 nanostructures for wastewater treatment
In the present study, single phase nickel based disulphide (NiS2) and diselenide (NiSe2) nanostructures were prepared hydrothermally in a short time span (4 h) under subcritical temperature (160 °C). The nanostructures grow in cubic crystal phases. Average crystallite sizes and intrinsic microstrains were determined using Williamson–Hall (W–H) plot analysis. Hollow NiS2 nanospheres and bipyramidal NiSe2 nanostructures are reported that are suitable for surface related applications. Thermal gravimetric analysis (TGA) indicated high stability of the nanostructures at elevated temperatures. Optical studies indicated visible light activeness of the nanostructures exhibiting sharp band edges. The nanostructures are mesoporous in nature with NiS2 and NiSe2 having respectively a large specific surface area of 310 m2/g and 177 m2/g. A primarily work done to determine the electrochemical nature of the nanostructures showed the materials are pseudo-capacitive in nature with specific capacitances of 1022 F/g and 480 F/g respectively for NiS2 and NiSe2. The photo-catalytic activity of the nanostructures was explored against a colourless pollutant; phenol. The nanostructures degraded most of the phenol (>90 %) under visible light illumination and the reusability experiments performed determined industrial value of the photocatalysts