A Micro-genetic Algorithm based Optimization of
Marine Propeller for Podded Propulsion System
- Md. Mashud Karim
Contact: mmkarim@name.buet.ac.bd
Abstract: A micro-genetic algorithm (mGA)
based optimization technique has been applied to the optimal design of marine
propeller for podded propulsion system. Firstly, boundary element method is (BEM)
used to predict open water performance of the propeller of a given sectional
geometry with different chord distribution, pitch distribution, thickness and
camber distributions. B-spline method is used to vary these distributions. The
optimization algorithm then searches for an improved propeller geometry which
gives highest performance satisfying some design requirements and imposed
constraints. Finally, the podded propulsion system using this propeller is
analyzed. In this study, micro-genetic algorithm (mGA)
is found useful and prospective tool for the design optimization of a
propeller for podded propulsion system due to its faster convergence.
Field Survey on Facility Damage of Yangon Harbor
by Cyclone NARGIS in 2008
- Tetsuya Hiraishi
Contact:
hiraishi@pari.go.jp
Abstract: Cyclone NARGIS was generated at the
north of Indian Ocean and it crossed the Ayeyarwady Delta on May 2nd, 2008. In
Yangon, the most populated city in Myanmar, its harbor area was damaged in the
storm surge due to the cyclone. Almost floating jetties in the harbor were
destroyed and their recovery has become an urgent subject because rescue
supplies to the devastated areas were loaded at Yangon harbor. A field survey
was conducted to study on the detail of damage related mainly to jetties and
to discuss on the future recovery planning. The survey results revealed that
the supporter of connection bridges became one of the weaker parts to be
considered and that the mooring system of pontoon was not suitable to high
tide due to the storm surge.
Reliability of Pipelines with
Non-uniform Corrosion
- A.P. Teixeira, A. Zayed and C. Guedes Soares
Contact: guedess@mar.ist.utl.pt
Abstract: This paper
presents a reliability analysis of non-uniform corroded pipelines under
internal pressure. In alternative to the uniform reduction of pipe thickness
due to corrosion or a localised area of reduced thickness, it considers the
spatial distribution of the thickness of the corroded pipeline represented by
stochastic simulation of random fields. The random fields of corrosion are
discretized and the maximum internal pressure is then assessed by finite
element analysis. The Monte Carlo simulation method is used to assess the
uncertainty of the estimates of the burst pressure of corroded pipelines. The
importance of the spatial representation of the corrosion by random fields in
alternative to the traditional approach based on a uniform reduction of
pipeline thickness is demonstrated. Finally, the probabilistic model of the
burst pressure of a pipeline with non-uniform corrosion thickness is used to
assess its reliability when subjected to internal pressure using the first
order reliability method (FORM).
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