- Type of paper
: Paper in journal
Title:
- Type of paper
: Paper in journal
Title:
- Authors:
- BOBANAC, NENAD (147720)
Journal: Brodogradnja
Number: 3-4
ISSN: 0007-215X
Volume: 40
Year: 1992
Pages: from 117 to 120
Language: engleski
Summary: A method and equipment for the observation of full scale
marine propeller cavitation on a fast small ship is presented. The design
of observing windows enables their relatively cheap and fast
mounting-dismounting without having expensive ship docking. The window with
an optical prism flat with bottom plating improves view angles without
disturbing the ship wake, and can be successufully used for photographing
of full scale marine propeller cavitation. The method allows easier and
cheaper collecting of full scale cavitation pattern data.
Keywords: ship propeller cavitation
- Type of paper
: Paper in journal
Title:
- Authors:
- GRUBIŠIĆ, RAJKO (74052)
- BOBANAC, NENAD (147720)
- SENJANOVIĆ, IVO (57053)
Journal: Brodogradnja
Number: 2
ISSN: 0007-215X
Volume: 42
Year: 1994
Pages: from 140 to 149
Language: engleski
Summary: An integral ship vibration prediction procedure consisting
of vibration analysis during the design stage is presented. For the
vibration analysis the finite element method was employed. By means of 1D,
2D and 3D models basic hull girder vibration, coupled hull-superstructure
vibration due to propeller excitation and vibration of the system after
body-main engine-superstructure due to engine excitation, respectively, was
investigated.
Keywords: ship vibration, ship vibration prediction
- Type of paper
: Paper in journal
Title:
- Authors:
- BOBANAC, NENAD (147720)
- GRUBIŠIĆ, RAJKO (74052)
- SENJANOVIĆ, IVO (57053)
Journal: Brodogradnja
Number: 2
Volume: 42
Year: 1994
Pages: from 221 to 331
Language: engleski
Summary: The vibration measurements consisting of excitation test
and ship trials measurements were compared with 1D, 2D and 3D FEM model
calculation results. Correlation of measurement results from excitation
tests and ship trials results was done. Many valuable conclusions were
made.
Keywords: ship vibration, ship vibration measurement, ship vibration prediction
- Type of paper
: Paper in journal
Title:
- Authors:
- SENJANOVIĆ, IVO (57053)
- FAN, YIN
Journal: Computers & Structures
Number: 1
ISSN: 0045-7949
Volume: 43
Year: 1992
Pages: from 31 to 52
Number of references: 27
Language: engleski
Summary: A new flexural and torsional theory of thin-walled girders
is presented by introducing the concept of effective stiffness and mass
parameters as modal quantities. For this purpose a rather simple vibration
analysis of simple supported girders is performed. Due to sinusoidal modes
the problem is reduced to the girder cross-section plane. The stiffness and
mass properties are determined from equivalence of girder deformation
energy and inertia work, respectively and its beam idealization that
results in the same natural frequencies. Therefore, this beam theory is
more accurate than the classical one. For practical reasons the
finite element formulation is applied, employing orthotropic strip elements
that are necessary for the ship structures. The developed computer program
is tested in case of a square tube and a channel girder. For illustration,
analysis of a container ship midship section is performed.
Keywords: ship structure, ship vibration, thin-walled girder
- Type of paper
: Paper in proceedings
Title: Ship screw propeller cavitation recording with angle
sampling control
- Authors:
- BOBANAC, NENAD (147720)
- VIČIĆ, DARKO
- Editors
- VIDMAR, BRANKO
Proceedings title: 35. Međunarodni simpozij ELMAR-a ZADAR
Language: hrvatski
Place: Zadar
Year: 1993
ISBN/ISSN: 1330-092X
Pages: from 266 to 269
Meeting: 35. Međunarodni simpozij ELMAR-a ZADAR
Held: from 09/20/93 to 09/22/93
Summary: A method of magnetic, video and photo recording of ship
screw propeller cavitation is presented. A device developed for generating
a set of triggering signals following the angle position of a rotating
propeller is described. The method is employed for postdetectional A/D
conversion synchronized with the rotational speed and angle position of the
rotating propeller, for the complete restoration of pressure pulse signals
induced by a cavitating propeller revolution by revolution, and for the
correlation between video records and hull pressure pulse records.
Keywords: ship propeller cavitation, propeller excitation
- Type of paper
: Paper in proceedings
Title:
- Authors:
- SMILJANIĆ, BRANIMIR
- BOBANAC, NENAD (147720)
- SENJANOVIĆ, IVO (57053)
Proceedings title: Proc. of the International Conference on Hydroelasticity in Marine Technology
Language: engleski
Place: Trondheim, Norway
Year: 1994
Meeting: International Conference on Hydroelasticity in Marine Technology
Held: from 05/25/94 to 05/27/94
Summary: The theory of interaction of an underwater explosion gas
bubble with a nearby ship hull structure is outlined. The excitation due to
bubble pulsation is determined for two types of explosive on the basis of
the bubble pulsation theory, using the pulsation period measurement
results. The numerically obtained dependence of the maximum bending moment
on the mass and depth of explosive for two different ship hulls is
discussed.
Keywords: underwater explosion, effect of underwater explosion on ship hull
- Type of paper
: Paper in proceedings
Title:
- Authors:
- BOBANAC, NENAD (147720)
- Editors
- ANDROČEC, VLADIMIR
- LOVRIĆ, JOSIP
Proceedings title: Proc. of the 7th Congress of the Int. Maritime Association of Mediterranean
Language: engleski
Place: Dubrovnik
Year: 1995
ISBN/ISSN: 953-6017-02-4
Pages: from 863 to 870
Meeting: 7th Congress of the International Maritime Association of the Mediterranean
Held: from 04/23/95 to 04/27/95
Summary: The interactive software package HULPRES is developed for
statistical analyses based on one propeller revolution signal length. The
Gaussian and Rayleigh distributions are at disposal for matching. The
algorithm and the possibilities of the HULPRES are described. The full
scale and model scale experimental results show that the hypothesis of
normal distribution is not generally valid. In the majority of cases when
harmonics are not normally distributed the Rayleigh distribution is the
best choice.
Keywords: propeller induce hull pressures, statistical analysis of hull pressures
- Type of paper
: Paper in proceedings
Title:
- Authors:
- RADANOVIĆ, BOŽIDAR (112954)
- Editors
- ANDROČEC, VLADIMIR
- LOVRIĆ, JOSIP
Proceedings title: Proc. of the 7th Congress of the Int. Maritime Association of the Mediterranean
Language: engleski
Place: Dubrovnik
Year: 1995
ISBN/ISSN: 953-6017-02-4
Pages: from 871 to 880
Meeting: 7th Congress of the International Maritime Association of the Mediterranean
Held: from 04/23/95 to 04/27/95
Summary: A review of the influence of complex ship structure on
sound transmission through it is given. Empirical models of sound
propagation are presented as the basis for preliminary prediction in the
early stage of ship design. Some special means of additional
structure-borne sound reduction are described.
Keywords: ship noise, sound transmission via ship structure
- Type of paper
: Paper in proceedings
Title:
- Authors:
- JURAS, KRSTE (143135)
- Editors
- ANDROČEC, VLADIMIR
- LOVRIĆ, JOSIP
Proceedings title: Proc. of the 7th Congress of the Int. Maritime Association of the Mediterranean
Language: engleski
Place: Dubrovnik
Year: 1995
ISBN/ISSN: 953-6017-02-4
Pages: from 798 to 808
Meeting: 7th Congress of the International Maritime Association of the Mediterranean
Held: from 04/23/95 to 04/27/95
Summary: During preliminary design of a large container vessel, the
problem of possible too high noise levels in accommodation spaces was
noticed. Namely, the accommodation area was situated in the close vicinity
of a powerful main engine/propeller and a few diesel generators. Besides,
the engine exhaust system was passing through some superstructure decks,
which caused an additional problem. The author, on the basis of his own
investigations mainly, made the noise prediction calculation and designed
the acoustical treatment of the accommodation and working spaces. The noise
measurements performed onboard the first vessel completely confirmed the
prediction, the noise levels being below the permissible levels speci-fied
by the shipowner. This served as the basis for some local interventions on
the ship structure and accommodation onboard the sister ship, which
resulted in additional noise reduction.
Keywords: ship noise, ship noise control
- Type of paper
: Paper in proceedings
Title: Locally applied noise control measures in ship spaces
- Authors:
- RADANOVIĆ, BOŽIDAR (112954)
- MIRKOVIĆ, GORAN (143146)
- Editors
- VIDMAR, BRANKO
Proceedings title: 35. Međunarodni simpozij ELMAR-a ZADAR, Zbornik radova
Language: hrvatski
Place: Zadar
Year: 1993
ISBN/ISSN: 1330-092X
Pages: from 292 to 295
Meeting: 35. Međunarodni simpozij ELMAR-a ZADAR
Held: from 09/20/93 to 09/22/93
Summary: The necessity and effectivness of locally applied noise
control
measures in ship spaces is analysed. Predicted and measured noise
levels are compared on several examples.
Keywords: ship noise, noise control in ship spaces
- Type of paper
: Paper in proceedings
Title: Forced torsional vibration of the ship propulsion system
- Authors:
- MUTEVELIĆ, DAMIR (181725)
- Editors
- VIDMAR, BRANKO
Proceedings title: 35. Međunarodni simpozij ELMAR-a ZADAR, Zbornik radova
Language: hrvatski
Place: Zadar
Year: 1993
ISBN/ISSN: 1330-092X
Pages: from 285 to 291
Meeting: 35. Međunarodni simpozij ELMAR-a ZADAR
Held: from 09/20/93 to 09/22/93
Summary: Torsional vibration measurement methods are introduced, and
the review of the torsional vibration problems relating to ship propulsion
systems is given. The method of measuring torsional vibration using strain
gauges is presented, and the analysis of the torsional vibration results is
illustrated on one example. The forced torsional vibration calculation
method used for defining additional torsional stresses in all the parts of
the propulsion system on the basis on the measurement results is presented
in the same example.
Keywords: torsional vibration of the ship propulsion system
- Type of paper
: Paper in proceedings
Title: Screw propeller influence on noise in smaller ships
- Authors:
- JURAS, KRSTE (143135)
- Editors
- VIDMAR, BRANKO
Proceedings title: 35. Međunarodni simpozij ELMAR-a, Zbornik radova
Language: hrvatski
Place: Zadar
Year: 1993
ISBN/ISSN: 1330-092X
Pages: from 313 to 315
Meeting: 35. Međunarodni simpozij ELMAR-a ZADAR
Held: from 09/20/93 to 09/22/93
Summary: The results of researching the screw propeller as a source
of noise in accommodation spaces of smaller ships are given. Some noise
influencing propeller parameters like transmitted power, RPM and clearance
are preliminary analysed.
Keywords: ship noise, ship propeller noise
- Type of paper
: Paper in proceedings
Title:
- Authors:
- RADANOVIĆ, BOŽIDAR (112954)
- Editors
- VIDMAR, BRANKO
- MEDVED ROGINA, BRANKA
- RADANOVIĆ, BOŽIDAR (112954)
Proceedings title: Proc. of the 37th International Symposium Electronics in Marine
Language: engleski
Place: Pula
Year: 1995
ISBN/ISSN: 1330-092X
Pages: from 47 to 51
Meeting: 37th ELMAR International Symposium
Held: from 09/18/95 to 09/20/95
Summary: Ventilation and exhaust systems are sources of considerable
noise on board ships and in many other structures. In this paper typical
acoustical filters applied for noise reduction in ventilation and exhaust
duct systems are described.
Keywords: noise silencers, mufflers
- Type of paper
: Paper in proceedings
Title:
- Authors:
- JURAS, KRSTE (143135)
Proceedings title: Proceedings of the PRADS'92
Language: engleski
Place: Newcastle upon Tyne, Vel. Britanija
Year: 1992
Meeting: PRADS'92 - Practical Design of Ships and Mobile Units
Summary: Very high noise levels were measured onboard a powerful tug
during the trial. Due to technical reasons, acoustical treatment was
undertaken on the sister ship. The treatment included fitting of
viscoelastic layers, floating floors and sound absorptive ceilings. On the
basis of the obtained results the treatment was
improved on the first ship during inspection and testing. Although the
treatment of noise sources was not feasible, the results of the noise
reduction were impressive - nearly 10 dBA in some accommodation spaces. The
focus of the paper is on the real assessment of damping materials
efficiency, particularly in comparison with some conventional treatment
solutions.
Keywords: ship noise, ship noise control
- Type of paper
: Paper in proceedings
Title: Noise reduction of hydraulic systems
- Authors:
- RADANOVIĆ, BOŽIDAR (112954)
- Editors
- VIDMAR, BRANKO
Proceedings title: 36. Međunarodni simpozij ELMAR-a, Zbornik radova
Language: hrvatski
Place: Zadar
Year: 1994
ISBN/ISSN: 1330-092X
Pages: from 9 to 12
Meeting: 36. Međunarodni simpozij ELMAR-a ZADAR
Held: from 09/12/94 to 09/14/94
Summary: Hydraulic systems are sources of considerable noise on
board ships. Hydraulics noise generation and control using various
silencing measures are described. A design method for an acoustical pipe
silencer is presented.
Keywords: hydraulic system noise, hydraulic noise silencers
- Type of paper
: Summary in proceedings
Title:
- Authors:
- RADANOVIĆ, BOŽIDAR (112954)
Proceedings title: 14th Int. Congress on Acoustics, Acustica, Vol. 76, 1992, Supplement to No. 4
Language: engleski
Place: Stuttgart, SR Njemačka
Year: 1992
ISBN/ISSN: 0942-0770
Pages: from 109 to 109
Meeting: 14th International Congress on Acoustics
Held: from 09/03/92 to 09/10/92
Summary: The majority of mechanical structures such as ships and
other vehicles, as well as some machines and buildings are made of ribbed
plates composed of rectangular panel elements. A method for the estimation
of sound radiation from such plates is derived. The method is based on
Maidanik's approximate analytical expressions for multimode radiation
caused by broad-band mechanical excitation modified according to empirical
data. The applicability of the method is checked on some practical
examples.
Keywords: sound radiation, ship noise
- Type of paper
: Technical report
Title:
- Authors:
- VLAŠIĆ, DALIBOR (181815)
Ordering party: Brodogradilište "GREBEN"
Institution depot: Brodarski institut
Year: 1992
Number of pages: 25
Language: engleski
Summary: The aim of acceleration measurements on the free-fall
lifeboat model and prototype during its launching is the determination of
the hull and crew loading caused by an impact of the boat with the water
surface. For that reason the level of the acceleration has to be measured
at the most critical seat location in all three main directions. During the
development of a free-fall lifeboat it is possible to predict the level of
acceleration of full-scale lifeboat with tests carried out on the model.
Keywords: free-fall lifeboat, shock measurements on free-fall lifeboat