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The Rescue Wing: Design of a Marine Distress Signaling Device
KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
KTH, School of Computer Science and Communication (CSC), Numerical Analysis and Computer Science, NADA.
2005 (English)In: Proceedings of MTS/IEEE OCEANS, 2005, 2005, 1640129- p.Conference paper, Published paper (Refereed)
Abstract [en]

We present a multidisciplinary scientific analysis combining aerodynamics, flight mechanics and electromagnetics aiming at the design of a new marine distress signaling device. We show how computational fluid dynamics (CFD) and computational electromagnetics (CEM) techniques have been used to assist In the design of both the flight characteristics and the radar performance of the device, as well as how its radar signature compares to popular radar reflectors used on yachts and sailboats.

Place, publisher, year, edition, pages
2005. 1640129- p.
Series
Oceans-IEEE, ISSN 0197-7385
Keyword [en]
Aerodynamics, Computational fluid dynamics, Electromagnetic fields, Flight dynamics, Radar reflection, Radar systems
National Category
Vehicle Engineering
Identifiers
URN: urn:nbn:se:kth:diva-5804DOI: 10.1109/OCEANS.2005.1640129ISI: 000238978702089Scopus ID: 2-s2.0-33947221013OAI: oai:DiVA.org:kth-5804DiVA: diva2:10305
Conference
MTS/IEEE OCEANS, 2005; Washington, DC; 18 September 2005 through 23 September 2005
Note
QC 20100910Available from: 2006-05-29 Created: 2006-05-29 Last updated: 2010-10-04Bibliographically approved
In thesis
1. Multidisciplinary Design in Aeronautics, Enhanced by Simulation-Experiment Synergy
Open this publication in new window or tab >>Multidisciplinary Design in Aeronautics, Enhanced by Simulation-Experiment Synergy
2006 (English)Doctoral thesis, comprehensive summary (Other scientific)
Abstract [en]

This thesis covers some aspects of current aircraft design, and presents how experiment and simulation are used as tools. Together they give enhanced effects over employing either one separately. The work presented has been produced using both simulations and experiments. An overview of aircraft design tools is presented, together with a description of their application in research. Participation in two major design projects, HELIX and the Rescue wing, gave an opportunity to combine traditional experimental and computational tools. They also serve as a platform for developing two new tools, the vortex lattice program Tornado and the DoTrack camera based wind tunnel measurement system.

The HELIX project aimed at exploring new, unconventional high-lift systems, such as blown flaps, flaperons and active vortex generators. The concepts were investigated with an array of conceptual design tools, ranging from handbook methods to high Reynold’s number wind tunnels. The research was done in several stages. After each stage the concepts failing to reach specifications were discontinued. The active vortex generator concept is followed in detail from the first phase in the HELIX project, and was finally evaluated by full computational fluid dynamics (CFD) and wind tunnel testing.

The lessons learned in HELIX were applied to the Rescue wing project, where a kite balloon system for emergency localization was developed. The project is truly multidisciplinary, and both experiment and simulation had to be used in close conjunction. Lack of appropriate methods for measurement and analysis of this kind of device meant that new methods had to be developed.

Recent experience of academia working closely together with industry has shown substantial benefits to all parties involved. The synergy of computer modeling and simulation with experiment plays an important role in the common collaborative modus operandi of academia and industry. In particular, the later stages of aeronautic educational programmes should actively pursue such collaboration.

Place, publisher, year, edition, pages
Stockholm: KTH, 2006. xi, 43 p.
Series
Trita-AVE, ISSN 1651-7660 ; 2006:25
Keyword
Aeronautics, conceptual design, design, high lift systems
National Category
Vehicle Engineering
Identifiers
urn:nbn:se:kth:diva-3996 (URN)91-7178-373-3 (ISBN)
Public defence
2006-06-08, F3, Lindstedsvägen 26, Stockholm, 10:00
Opponent
Supervisors
Note
QC 20100910Available from: 2006-05-29 Created: 2006-05-29 Last updated: 2010-09-10Bibliographically approved
2. Computational electromagnetics: software development and high frequency modeling of surface currents on perfect conductors
Open this publication in new window or tab >>Computational electromagnetics: software development and high frequency modeling of surface currents on perfect conductors
2005 (English)Doctoral thesis, comprehensive summary (Other scientific)
Abstract [en]

In high frequency computational electromagnetics, rigorous numerical methods be come unrealistic tools due to computational demand increasing with the frequency. Instead approximations to the solutions of the Maxwell equations can be employed to evaluate th electromagnetic fields.

In this thesis, we present the implementations of three high frequency approximat methods. The first two, namely the Geometrical Theory of Diffraction (GTD) and th Physical Optics (PO), are commonly used approximations. The third is a new invention that will be referred to as the Surface Current Extraction-Extrapolation (SCEE).

Specifically, the GTD solver is a flexible and modular software package which use Non-Uniform Rational B-spline (NURBS) surfaces to model complex geometries.

The PO solver is based on a triangular description of the surfaces and includes fas shadowing by ray tracing as well as contribution from edges to the scattered fields. GTD ray tracing was combined with the PO solver by a well thought-out software architecture Both implementations are now part of the GEMS software suite, the General ElectroMag netic Solvers, which incorporates state-of-the-art numerical methods. During validations both GTD and PO techniques turned out not to be accurate enough to meet the indus trial standards, thus creating the need for a new fast approximate method providing bette control of the approximations.

In the SCEE approach, we construct high frequency approximate surface currents ex trapolated from rigourous Method of Moments (MoM) models at lower frequency. T do so, the low frequency currents are projected onto special basis vectors defined on th surface relative to the direction of the incident magnetic field. In such configuration, w observe that each component displays systematic spatial patterns evolving over frequenc in close correlation with the incident magnetic field, thus allowing us to formulate a fre quency model for each component. This new approach is fast, provides good control of th error and represents a platform for future development of high frequency approximations.

As an application, we have used these tools to analyse the radar detectability of a new marine distress signaling device. The device, called "Rescue-Wing", works as an inflatabl radar reflector designed to provide a strong radar echo useful for detection and positionin during rescue operations of persons missing at sea.

Place, publisher, year, edition, pages
Stockholm: KTH, 2005. xi, 39 p.
Series
Trita-NA, ISSN 0348-2952 ; 0541
Keyword
High frequency approximations, Maxwell’s equations, Method of Moments, Physical Optics, Geometrical Theory of Diffraction, Extraction Extrapolation
National Category
Computational Mathematics
Identifiers
urn:nbn:se:kth:diva-590 (URN)91-7178-203-6 (ISBN)
Public defence
2006-01-27, Sal D3, Lindstedtsvägen 5, Stockholm, 10:15
Opponent
Supervisors
Note
QC 20101004Available from: 2006-01-16 Created: 2006-01-16 Last updated: 2010-10-04Bibliographically approved

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