Download - Shipandoffshore.net

Cimac Congress | Shanghai 2013
leaf spring and span length was adjusted using half cylinder shape
supports. The aim of the concept was to make a simple low cost
solution with wide control range. The frequency range of studied
ATMD was approximately from 20 to over 100 Hz. The ATMD can
be used as a troubleshooting device with structures that have resonance
problem without an extinctive pre-study of the structure.
Moving mass and span length can be varied easily so the adjusting
of the ATMD can be done in situ. The ATMD was constructed using
many thin plates that were piled like a leaf spring. All the parts
in ATMD are steel so the temperature range is wide and also the
reliability is good. The ATMD concept proved to work excellent in
real scale laboratory test setup. Response of the self-excited 250 kg
test table was decreased approximately by 70 to 80%. The studied
ATMD concept was designed to use in the generator part of a diesel
generator set. The ATMD can also be used for example in other
engine, manufacturing and transport applications.
On the design of a single cylinder engine for
enhanced functional and reliability validation
Simon Brewster, Ricardo, UK
Martin Weinrotter, Guascor Power I+D SA, Spain
Aitor Larralde, Guascor Power I+D SA, Spain
Inaki Iruretagoiena, Guascor Power I+D SA, Spain
Carl Burrell, Ricardo, Czech Republic
The increasing global demand for power generation and transportation
presents a significant opportunity to the world’s large
engine producers, but presents a key question regarding the
protection of our environment and preservation of our natural
resources. Meeting these challenge require the introduction of
higher efficiency and cleaner engines to the market that extend
the known boundaries of performance whilst ensuring product
reliability. The successful delivery of these new engines with competitive
time to market demands a leap in development philosophy
and method. This paper presents the design approach for a
single-cylinder engine that in close combination with a powerful
analysis process enables the significant reduction of development
cost and duration, whilst substantially enhancing the fundamental
reliability achieved in new product development. Traditionally
single cylinder engines have been applied to the early life
evaluation of combustion processes. As such the flexibility in
configuration, greater refinement in test control and measurement,
reduced costs of prototype parts and operation, and reduced
test facility demands have accelerated the development
of ever cleaner and more efficient combustion systems. Coupled
with assessment of the combustion process there has existed the
opportunity for the preliminary durability assessment of certain
performance related components. This has been promising in
particular due to the much reduced overhead in operation. However,
there remains a substantial and unrealised opportunity in
the application of single-cylinder engines to the accelerated validation
of multi-cylinder engine function and reliability. In this
paper, the authors present this opportunity and the approach
to deliver both class-leading functionality and reliability. At first
the boundary conditions for operation representative of a multicylinder
engine may be established through the coupled use of
multi-cylinder and single-cylinder engine simulations. The gas
exchange processes that influence cylinder filling and trapping of
residual fractions, charge motion, and transport of emissions may
be determined such that early stage confirmation of the boosting
strategy can be given. Simulation of whole engine cooling and
lubrication flows coupled with detailed analysis of individual
cylinder operation gives confirmation of operating boundary
conditions and enables the single-cylinder replication of heat
exchange processes and component thermal loading, lubrication
and friction. Secondly, the architecture of the single-cylinder
engine is created such that the maximum commonality with engine
hardware may be achieved. Evidently this would include the
replication of bore and stroke, but also deck height, connecting
rod length and cylinder bore offset. Ensuring the use of common
big end bearings and entire valve train geometry will then enable
not only the use of common cylinder head and piston assemblies,
but also connecting rod, liner and all valve gear. The development
of rapid prototyping methods which align with production
design, materials and manufacturing processes ensures
the seamless transfer of designs to the production supply chain.
Thirdly, and with the foundation of representative components
operating under representative conditions, it becomes possible
to significantly extend the validation of both function and reliability.
With precise measurement of temperature, pressure and
strain, the thermal and mechanical performance of components
may be confirmed. Further, with representative thermal and mechanical
loading, and component deformation and dynamics,
the performance of the piston and cylinder liner systems, valve
train kinetics, and rotating and reciprocating friction may be confirmed.
Perhaps most significantly, early stage validation may be
obtained for predictions of component and system reliability,
which include analysis of high and low cycle fatigue correlated to
thermo-mechanical performance analyses and infield warranty
data. The application of such a design and analysis philosophy at
the early pro-approach to advanced manufacturing methods and
supply chain management, delivers significant functional and reliability
validation of engine design before committing to multicylinder
engine hardware. The possibility to deliver new, reliable
and more environmentally friendly engines is therefore realised.
Thursday May 16th / 10:30 – 12:00
Fundamental Engineering
Engine Development, Modelling, Simulation
Room A
Four-stroke opposed-piston-diesel-engine with
controlled shift-liners for optimised scavenging, low
heat losses and improved thermal efficiency
Guenter Elsbett, Guenter Elsbett Technologie, Germany
Zongying Gao, Jiangsu University, Jiangsu Province, China
Zhong Wang, Jiangsu University, Jiangsu Province, China
Ping Sun, Jiangsu University, Jiangsu Province, China
Deqing Mei, Jiangsu University, Jiangsu Province, China
Opposed piston engines (OPEs) are looking back to more than
100 years of history and have been produced as Otto and diesel
engines, offering a promising challenge in specific output and
thermal efficiency. Diesel OPEs have been used regularly for commercial
aircraft due to excellent power/weight ratio, but powering
also merchant ships with big engines of several thousands of kW.
Already 75 years ago, a brake efficiency of more than 40% could
be achieved. In recent decades, these engines seem to be forgotten
while the research and development engineers put their main
focus on emission improvement. Conventional OPE technology
is known for emission problems, especially caused by scraping
lubrication oil into in- and outlet ports, as common OPEs scavenging
is limited for use in two-stroke engines only. Now some
new developments in OPE technology show their relevance to
future power train challenges. Better thermal efficiency is attracting
the development engineers, as two pistons share only one
combustion chamber, thus leading to beneficial volume/surface
ratio of the combustion chamber. Nevertheless, also in most to-
72 SPECIAL
Schiff&Hafen | Ship&Offshore | May 2013