CVF ski-jump ramp profile optimisation for F-35B

2009 ◽  
Vol 113 (1140) ◽  
pp. 79-85 ◽  
Author(s):  
A. Fry ◽  
R. Cook ◽  
N. Revill
Keyword(s):  
Environmental Conditions ◽  
Landing Gear ◽  
Paper Briefly ◽  
Aircraft Carrier ◽  
Vehicle Performance ◽  
Theoretical Profile ◽  
Air Vehicle ◽  
Aircraft Configurations ◽  
Optimum Profile

Abstract This paper presents a summary of the principles and processes used to design a ski-jump ramp profile for the UK’s Future Aircraft Carrier (CVF) optimised for the Joint Strike Fighter (JSF). The paper includes an overview of the CVF and JSF programs, a history and summary of the ski-jump ramp and the principles of its use in the shipborne Short Take-Off (STO) manoeuvre. The paper discusses the importance of defining optimisation boundaries including specified objectives, aircraft configurations and environmental conditions. It then demonstrates the process of balancing the design drivers of air vehicle performance and landing gear loads to achieve an optimum profile. Comparisons are made between the proposed candidate CVF ramp profile and the current in service ski-jump design as designed for the Harrier family of aircraft. The paper briefly covers some of the important issues and factors that have been experienced when a theoretical profile is translated into a physical ramp fitted to a ship, principally the effects on aircraft operations due to build and in-service variation from the nominal profile.

Pathways to man for radionuclides released from disposal sites on land

1986 ◽  
Vol 319 (1545) ◽  
pp. 165-176
Keyword(s):  
Mathematical Models ◽  
Environmental Conditions ◽  
Radioactive Wastes ◽  
Paper Briefly ◽  
Exposure Pathways ◽  
Land Disposal ◽  
Radiological Impact ◽  
Far Future

To predict the potential radiological impact on man of the disposal of radioactive wastes it is necessary to identify all the events and processes that could cause releases of radionuclides into the environment, to estimate their probabilities of occurrence and to calculate their consequences, for both individuals and populations. This paper briefly reviews the types of releases that have to be considered for land disposal sites and describes the mathematical models used to calculate rates of transport of radionuclides through the environment and doses to man. The difficulties involved in predicting environmental conditions in the far future are discussed, in the light of the ways in which the results of consequence calculations will be used. Assessments of land disposal of long-lived and highly radioactive wastes are briefly reviewed, with the aim of identifying the most important radionuclides and exposure pathways, and the areas where the models and their databases require improvement.

Obtaining minimum-drag shapes through surrogate-based global optimization: An application to the aerodynamic shape design of the landing gear master cylinder

2017 ◽  
Vol 232 (15) ◽  
pp. 2858-2869 ◽  
Author(s):  
Esther Andrés-Pérez ◽  
Daniel González-Juárez ◽  
Mario J Martin-Burgos ◽  
Leopoldo Carro-Calvo ◽  
Sancho Salcedo-Sanz
Keyword(s):  
Shape Optimization ◽  
Landing Gear ◽  
Support Vector ◽  
Shape Design ◽  
Aerodynamic Shape Optimization ◽  
Master Cylinder ◽  
Aerodynamic Shape ◽  
Minimum Drag ◽  
Vector Machines ◽  
Aircraft Configurations

Nowadays, one of the priorities of the European Commission is to reduce the environmental impact of aviation through the advanced design of novel aircraft configurations. This is of utmost importance in order to decrease the environmental footprint of aviation and to reduce fuel consumption and make airlines more profitable. This implies that new methods and tools for aerodynamic shape optimization will have to be developed, allowing aircraft configurations that cannot be obtained with traditional strategies. This paper focuses on the application of enhanced methods in aerodynamic shape design optimization to enable advanced aircraft configurations. In particular, this work aims to demonstrate the feasibility of the proposed strategy to reach optimal configurations that are far away from its baseline geometry. For this purpose, evolutionary algorithms are combined with support vector machines and applied to the optimization of a baseline geometry for different flow conditions. In particular, the selected application is based on the shape optimization problem of the landing gear master cylinder. Results pointed out the feasibility of the mentioned strategy to enable novel configurations within an aerodynamic shape optimization process.

A Systematic Exploration of Wing Size on Flapping Wing Air Vehicle Performance

2015 ◽  
Author(s):  
John Gerdes ◽  
Hugh A. Bruck ◽  
Satyandra K. Gupta
Keyword(s):  
System Design ◽  
Flapping Wing ◽  
Wing Size ◽  
Vehicle Performance ◽  
Trade Offs ◽  
Systematic Exploration ◽  
Maximum Payload ◽  
Air Vehicle ◽  
Payload Capacity ◽  
Improved Performance

The design of a flapping wing air vehicle is dependent on the interaction of drive motors and wings. In addition to the wing shape and spar arrangement, sizing and flapping kinematics affect vehicle performance due to wing deformation resulting from flapping motions. To achieve maximum payload and endurance, it is necessary to select a wing size and flapping rate that will ensure strong performance and compatibility with drive motor capabilities. Due to several conflicting trade-offs in system design, this is a challenging problem. We have conducted an experimental study of several wing sizes at multiple flapping rates to build an understanding of the design space and ensure acceptable vehicle performance. To support this study, we have designed a new custom test stand and data post-processing procedure. The results of this study are used to build a design methodology for flapping wing air vehicles with improved performance and to highlight system design challenges and strategies for mitigation. Using the methodology described in this paper, we have developed a new flapping wing air vehicle called the Robo Raven II. This vehicle uses larger wings than Robo Raven and flight tests have confirmed that Robo Raven II has a higher payload capacity.

Helicopter icing

2010 ◽  
Vol 114 (1152) ◽  
pp. 83-90 ◽  
Author(s):  
Y. Cao ◽  
K. Chen
Keyword(s):  
Cfd Simulation ◽  
Simulation Methods ◽  
Calculation Methods ◽  
Vehicle Performance ◽  
Wide Range ◽  
Air Vehicle ◽  
Alternative Means ◽  
Numerical Simulation Methods ◽  
Helicopter Aerodynamics ◽  
Computational Fluid Dynamics Cfd

Abstract Due to constraints of natural condition, cost and of available time associated with model fabrication and for extensive wind-tunnel tests or flight tests, Computational Fluid Dynamics (CFD) simulation was considered an alternative means of providing air vehicle icing simulation and aeromechanic performance analysis. Full-scale icing experiments and, therefore, certification and cost can be significantly reduced by developing full-numerical simulation methods to evaluate the air vehicle performance for a wide range of icing conditions. This paper summarises helicopter icing simulation methods that include the development of helicopter aerodynamics, calculation methods of helicopter icing, icing protection system performance, icing effects on the helicopter performance, and some challenges in helicopter icing simulation.

Aerodynamic and structural design of a solar-powered micro unmanned air vehicle

2000 ◽  
Vol 214 (2) ◽  
pp. 97-106 ◽  
Author(s):  
C Wilson ◽  
J Nutbean ◽  
I Bond
Keyword(s):  
Structural Design ◽  
Solar Power ◽  
Size Range ◽  
Small Scale ◽  
Unmanned Air Vehicle ◽  
Air Vehicle ◽  
Solar Powered ◽  
Aircraft System ◽  
Technological Improvements ◽  
Aircraft Configurations

The field of micro unmanned aerial vehicles ((μUAVs) has advanced rapidly in recent years. This paper studies the design and construction of a small solar-powered aircraft near the size range of current (μUAVs. A number of aspects of their design were analysed, including structural, aerodynamic and propulsion system considerations. The effect of small-scale, low Reynolds number aerodynamics was investigated, and the performance of a range of candidate aerofoils was compared. The integration of a solar power source into the aircraft system was considered a key design issue. Consequently, a number of aircraft configurations were examined, with the intention of optimizing the application of solar power in a miniature aircraft. Investigation of improved system components suggests that a practical solar-powered aircraft in the size range below 500 mm maximum linear dimension should be viable given modest technological improvements.

scholarly journals The disappearing cryosphere in the southeastern Alps: Introduction to special issue

2020 ◽  
Vol 60 (2) ◽  
pp. 109-124
Author(s):  
Matija Zorn ◽  
Blaž Komac ◽  
Anne Carrey ◽  
Mauro Hrvatin ◽  
Rok Ciglič ◽  
...  
Keyword(s):  
Climate Change ◽  
Environmental Conditions ◽  
River Ice ◽  
Special Issue ◽  
Paper Briefly ◽  
Important Indicator ◽  
Body Of Knowledge

Various ice bodies are an important source of paleoenvironmental data, and their study improves the understanding of present and future environmental conditions. Their changes are an important indicator of climate change. This special issue of Acta geographica Slovenica draws attention to the changing and disappearing cryosphere across the globe, with an emphasis on the southeastern Alps, and the necessity to conduct research in this field before the ice disappears forever. This paper briefly summarizes the current body of knowledge on glaciers, permafrost, cave ice, lake and river ice, and snow in the southeastern Alps, and it presents the contribution of Acta geographica Slovenica to this research and the main highlights of all five papers included in this special issue.

Elastic Element Integration for Improved Flapping-Wing Micro Air Vehicle Performance

2013 ◽  
Vol 29 (1) ◽  
pp. 32-41 ◽  
Author(s):  
Ranjana Sahai ◽  
Kevin C. Galloway ◽  
Robert J. Wood
Keyword(s):  
Elastic Element ◽  
Flapping Wing ◽  
Micro Air Vehicle ◽  
Vehicle Performance ◽  
Air Vehicle
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