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Development of a high speed planing trimaran with hydrofoil support /Grobler, Barend January 2007 (has links)
Thesis (MScIng)--University of Stellenbosch, 2007. / Bibliography. Also available via the Internet.
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Comparative evaluation of a hydrofoil-assisted trimaran /Moolman, Ryno. January 2005 (has links)
Thesis (MScIng)--University of Stellenbosch, 2005. / Bibliography. Also available via the Internet.
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Structural loading of cross deck connections for trimaran vessels /Rhoads, Jason L. January 1900 (has links)
Thesis (Naval Engineer and M.S.)--Massachusetts Institute of Technology, 2004. / Cover title. Available from National Technical Information Service, Springfield, Va., 2004. Includes bibliographical references (p. 67-69). Also available online.
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Wave making resistance characteristics of trimaran hulls /Elcin, Zafer. January 2003 (has links) (PDF)
Thesis (M.S. in Mechanical Engineering)--Naval Postgraduate School, December 2003. / Thesis advisor(s): Fotis Papoulias. Includes bibliographical references (p. 73). Also available online.
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Sensitivity analysis of the seakeeping behavior of trimaran ships /Kurultay, Aziz Alper. January 2003 (has links) (PDF)
Thesis (M.S. in Mechanical Engineering)--Naval Postgraduate School, December 2003. / Thesis advisor(s): Fotis Papoulias. Includes bibliographical references (p. 67-69). Also available online.
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Structural loading of cross deck connections for trimaran vesselsRhoads, Jason L January 2004 (has links)
Thesis (Nav. E.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2004. / This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. / Includes bibliographical references (p. 67-69). / This work investigates the fundamental relationships of wave loading on cross deck structures for trimaran vessels. In contrast with a monohull ship, trimaran vessels experience several possible structural loading cases including: longitudinal bending, transverse bending, torsional bending, spreading and squeezing of hulls, inner and outer hull slam pressures, wet deck slam pressures, loading from ship's motions, and whipping of slender hulls. This work investigates wave loading cases that result in transverse and torsional bending of the cross deck structure. The wave loading cases investigated include: side hull troughing and cresting in longitudinal waves, side hull torsion in longitudinal waves, and transverse hogging and sagging. For each of these load cases, a design load using a fully statistical sea state was derived using an analytical model of a trimaran represented by rigidly connected box barges. The design loadings with a reliability index of 5 for almost 500 trimaran configurations were calculated varying main hull length, side hull length, side hull transverse placement, and side hull longitudinal placement. The design loadings were curve fit to a fourth order polynomial in the three independent variables. / (cont.) The load predictions of the analytical box model of a trimaran were applied to a trimaran vessel with a realistic hull form using the finite element ship structural analysis program MAESTRO. Given the number of approximations and assumptions in the analytical model, the forces predicted by analytical model agreed closely with the finite element model's results. The fitted curve of design loadings allows an initial design stage loading estimate for cross deck structural loading, given general characteristics of length and spacing of a trimaran's hulls. This estimate of structural loading combined with other characteristics of good trimaran design including stability, roll, and resistance characteristics will aid in optimizing an overall trimaran ship design. / by Jason L. Rhoads. / S.M. / Nav.E.
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Comparative evaluation of a hydrofoil-assisted trimaranMoolman, Ryno 12 1900 (has links)
Thesis (MScEng (Mechanical and Mechatronic Engineering))--University of Stellenbosch, 2005. / This work is concerned with the design and hydrodynamic aspects of a hydrofoil-assisted
trimaran. A design and configuration of a trimaran is evaluated and the performance of a
hydrofoil-assisted trimaran is effectively compared to the performance of a hydrofoil-assisted
catamaran with similar overall displacement and same speed. The performance of the trimaran
with different outrigger clearances are also evaluated and compared. The hydrodynamic aspects
focuses mainly on the performance and to a lesser extend on the sea-keeping and stability of a
hydrofoil-assisted trimaran. The results were determined by means of experimental testing,
theoretical analysis and numerical analysis. The project was initiated as a result of the success of
the hydrofoil-assisted catamarans and due to the fact that there does not exist a hydrofoil-assisted
trimaran (to the author’s knowledge) where the main focus of the foils is to significantly reduce
the resistance.
A brief history, recent developments and associated advantages regarding trimarans are
discussed. A complete theoretical model is presented to evaluate the lift and drag of the
hydrofoils, as well as, the resistance of the trimaran. The data so obtained is then used to compare
the reliability and feasibility of the numerical and experimental predicted values.
The design of the trimaran and hydrofoil system is explained, together with the problems
associated with the final design of the trimaran. The design of a trimaran is much more
complicated than a catamaran due to more design variables being associated with trimarans. The
selection of the trimaran configuration is done in a logical manner considering stability and
hydrodynamics. However, the hydrofoil-assisted trimaran is closely adapted to the main
dimensions of the comparable hydrofoil-assisted catamaran.
An in-depth discussion of the testing technique used and the problems that are associated with
towing tank testing will facilitate similar tests in the future. The scaling method of Froude was
modified to account for the different sized hulls. The numerical methods are explained, with
emphasis on accuracy, limitations, feasibility and the time required to complete a calculation. The results are presented in an order suggested by the experimental and numerical work carried
out. The resistance, trim and rise/sinkage results are presented with speed for both the trimaran
and catamaran with and without the addition of foils. The addition of the foils supplies results
based on the amount of lift the foils carry and therefore can easily clarify the significant
resistance advantage the foils offer the trimaran and the catamaran evaluated in this project.
The final design and results of the evaluated trimaran are discussed. It is concluded that the
catamaran with similar displacement and speed is still superior to the trimaran, with and without
foils in both cases. The addition of foils to the trimaran does decrease the resistance significantly.
The conclusions regarding these results are presented, together with recommendations for future
work.
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Development of a high speed planing trimaran with hydrofoil supportGrobler, Barend 12 1900 (has links)
Thesis (MScEng (Mechanical and Mechatronic Engineering))--University of Stellenbosch, 2007. / The successful use of hydrofoil systems on catamarans, such as the Hysucat, led to the
development of a similar foil system for a high speed trimaran.
Firstly a mathematical model was developed to calculate the equilibrium planing conditions of a
planing trimaran. This was then used in the hydrodynamic design of a fully planing trimaran with
a design speed of 65 kn. The mathematical model was then modified to include the effects of
added hydrofoils. This model was then used to design a hydrofoil support system for the planing
trimaran.
Towing tank tests were then performed on a scale model of the boat, with and without the
supporting hydrofoil system. This was done to verify the theoretical design and to gather
resistance data, which could then be compared to other boats.
The results showed a notable improvement in efficiency of the boat with the addition of foils. The
conclusion was made that with the addition of a well-designed foil system, hull efficiencies
similar to that expected for the Hysucat, can be attained when the foil system is added to the
trimaran.
As this work was focused mainly on the high-speed performance of the boat, it is not certain how
the boat will perform through the speed-range. It is therefore recommended that further testing be
done, to determine the performance of the boat at lower speeds.
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