An Approximate Method for Intact Stability of Fishing Vessels

1999 ◽  
Vol 36 (03) ◽  
pp. 171-174
Author(s):  
Hüseyin Yilmaz ◽  
Abdi Kükner
Keyword(s):  
Design Stage ◽  
Design Parameters ◽  
Preliminary Design ◽  
Ship Stability ◽  
Fishing Vessels ◽  
Initial Stability ◽  
Intact Stability ◽  
Preliminary Design Stage ◽  
Reduce Risk ◽  
Vessel Stability

It is well known that stability is the most important safety requirement for ships. One should have some information on ship stability at the preliminary design stage in order to reduce risk. Initial stability of ships is an important criterion and can be closely evaluated in terms of form parameters and vertical center of gravity. In this study, using some sample ship data, approximate formulations are derived by means of regression analysis for the calculations expressed in terms of ship preliminary design parameters that can easily provide approximate GM calculations. Thus designers can be provided with ship stability at the preliminary design stage, and also a set of appropriate design parameters for improving vessel stability can easily be determined.

scholarly journals An Approximate Method for Calculation of Mean Statistical Value of Ship Service Speed on a Given Shipping Line , Useful in Preliminary Design Stage

2015 ◽  
Vol 22 (1) ◽  
pp. 28-35
Author(s):  
Katarzyna Żelazny
Keyword(s):  
Wind Waves ◽  
Parametric Method ◽  
Weather Conditions ◽  
Economic Effects ◽  
Design Stage ◽  
Design Parameters ◽  
Preliminary Design ◽  
Screw Propeller ◽  
Calm Water ◽  
Preliminary Design Stage

Abstract During ship design, its service speed is one of the crucial parameters which decide on future economic effects. As sufficiently exact calculation methods applicable to preliminary design stage are lacking the so called contract speed which a ship reaches in calm water is usually applied. In the paper [11] a parametric method for calculation of total ship resistance in actual weather conditions (wind, waves, sea current), was presented. This paper presents a parametric model of ship propulsion system (screw propeller - propulsion engine) as well as a calculation method, based on both models, of mean statistical value of ship service speed in seasonal weather conditions occurring on shipping lines. The method makes use of only basic design parameters and may be applied in preliminary design stage.

An Approximate Method for Cross Curves of Cargo Vessels

2001 ◽  
Vol 38 (02) ◽  
pp. 92-94
Author(s):  
Huseyin Yilmaz ◽  
Mesut Giiner
Keyword(s):  
Prediction Method ◽  
Design Stage ◽  
Series Data ◽  
Design Parameters ◽  
Preliminary Design ◽  
Hull Form ◽  
Beam Depth ◽  
Preliminary Design Stage ◽  
The Mathematical Model ◽  
Load Conditions

In this study, a formula is presented to estimate cross curves of cargo vessels and to predict statical stability at the preliminary design stage of the vessel. The predictive technique is obtained by regression analysis of systematically varied cargo vessel series data. In order to achieve this procedure, some cargo vessel forms are generated using Series-60. The mathematical model in this predictive technique is constructed as a function of design parameters such as length, beam, depth, draft, and block coefficient. The prediction method developed in this work can also be used to determine the effect of specific hull form parameters and the load conditions on stability of cargo vessels. The present method is applied to a cargo vessel and then the results of the actual ship are compared with those of regression values.

Simulation of CO Emission in Primary and Secondary Zone of a Small Gas Turbine Combustion Chamber Using CFD and Reactors Network

2019 ◽  
Author(s):  
Ivan A. Zubrilin ◽  
Nikita I. Gurakov ◽  
Alexander S. Semenikhin ◽  
Oleg V. Kolomzarov ◽  
Sergey G. Matveev ◽  
...  
Keyword(s):  
Combustion Chamber ◽  
Residence Time ◽  
Equivalence Ratio ◽  
Pollutant Emissions ◽  
Design Stage ◽  
Design Parameters ◽  
Preliminary Design ◽  
Environmental Characteristics ◽  
Preliminary Design Stage ◽  
Secondary Zone

Abstract In this paper the influence of various parameters of the primary and secondary zones of a small-sized combustion chamber on its environmental characteristics was studied. The study of the environmental characteristics of the combustion chamber was carried out in two ways. The first method consisted of two steps. The first step was a 3D simulation of combustion processes using FGM combustion model. The second step was based on results of the first step using reactors network implemented in the ANSYS Fluent 18.2 software. The construction of the reactors network in this approach occurred automatically according to a temperature and mixture fraction. The number of reactors in the result was about 500. The second method was a simple model of a reactors network in which the primary zone was simulated by a perfectly stirred reactor, and the secondary zone was a plug flow reactor. Methane was used as a fuel. The influence of the residence time of the mixture and fuel-air equivalence ratio in each zone on the emission of CO and NOx at the combustion chamber exit was studied. The residence time and fuel-air equivalence ratio for the first method were changed using the design parameters of the combustion chamber. For a simple reactors network, these parameters are set as input data, so this method can be used at the preliminary design stage. As a result of the work, a method was obtained that allows to find the parameters of the primary and secondary zones of the combustion chamber in order to minimize pollutant emissions at the preliminary design stage.

Preliminary Design of Ship Lines by Mathematical Methods

1970 ◽  
Vol 14 (01) ◽  
pp. 52-65
Author(s):  
G. Kuiper
Keyword(s):  
Design Method ◽  
Design Stage ◽  
Design Parameters ◽  
Mathematical Representation ◽  
Preliminary Design ◽  
Mathematical Methods ◽  
Qualitative Design ◽  
Preliminary Design Stage

A description is given of a mathematical representation of the ship's hull. The ship form can be given by a number of parameters, which are connected with the usual design parameters of a lines plan. Some qualitative design parameters such as U-or V-shaped sections can be formulated numerically. A design method is given which does not need more information than available at the preliminary design stage. Some results and variations are presented.

scholarly journals Shaping the appearance of a long-range aircraft at the stage of developing a technical proposal

2020 ◽  
Vol 47 (3) ◽  
pp. 49-59
Author(s):  
A. A. Gorbunov ◽  
A. D. Pripadchev
Keyword(s):  
Long Range ◽  
Rational Design ◽  
Performance Criteria ◽  
Design Stage ◽  
Design Solution ◽  
Design Parameters ◽  
Preliminary Design ◽  
Efficiency Criterion ◽  
Rational Design Parameters ◽  
Preliminary Design Stage

Objective. The process of designing a long-range aircraft, in particular at the preliminary design stage, involves comparing and analyzing a large number of design alternatives with specified performance criteria. At the same time, the problem of choosing the composition of rational design parameters is solved, which is an actual problem of the preliminary design stage of a long-range aircraft. Methods. The developed method allows determining the vector of parameters that provides rational characteristics for a given efficiency criterion. In this regard, the authors propose to introduce a global efficiency criterion - the takeoff weight of the long-range aircraft, and the specific criteria are the aerodynamic quality in cruise and the value of fuel efficiency. Results. In this formulation of the design problem, it is necessary to solve several interrelated problems, some of which are formalized, while others do not yet have a mathematical construct and software that allows automating the process. A distinctive feature of the proposed approach to finding a rational design solution is the use of statistical analysis methods in combination with methods of high-precision mathematical modeling, software-implemented in a single information environment using the Fortran V and C++ languages. Conclusion. The proposed method for selecting the composition of rational design parameters allows forming the appearance and providing the specified characteristics for its component elements at the early stages and stages of designing the long-range aircraft.

scholarly journals Weight Estimation of Marine Propulsion and Power Generation Machinery

2021 ◽  
Author(s):  
Arun Kr Dev ◽  
Makaraksha Saha
Keyword(s):  
Power Generation ◽  
Diesel Engines ◽  
Power Output ◽  
Design Stage ◽  
Preliminary Design ◽  
Independent Variables ◽  
Marine Propulsion ◽  
Intact Stability ◽  
Marine Diesel ◽  
Preliminary Design Stage

During the conceptual and preliminary design stage of a ship, designers need to ensure that the selected principal dimensions and parameters are good enough to deliver a stable ship (statically and dynamically) besides deadweight and speed. To support this, the initial intact stability of the proposed ship is required to be calculated, and in doing so, the lightship weight and its detailed breakdown are necessary to be known. After hull steel weight, machinery weight, mainly, marine propulsion and power generation machinery, play a vital role in the lightship weight estimate of a ship due to its robustness. The correct estimation of respective weights improves the accuracy of calculating a ship's initial stability typically to be designed and built. Hence, it would be advantageous for the designer to convince the ship owner. A total of 3006 marine propulsion (main marine diesel) engines and 348 power generation (auxiliary marine diesel) engines/generators of various power output (generators output for auxiliary engines), engine RPM and cylinder number of different engine makers are collected. These are analyzed and presented in both tabular and graphical forms to demonstrate the possible relationship between marine propulsion engine weight and power generation engine weight, and their respective power output, RPM, cylinder number, power-RPM ratio and power-RPM ratio per cylinder.In this article, the authors have attempted to investigate the behavior of marine propulsion engine weight and power generation engine/generator weight regarding engine power output, generator power output, engine RPM and cylinder number (independent variables). Further attempts have been made to identify those independent variables that influence the weight of the marine propulsion engine and power generation engine/generator (dependent variables), and their interrelationships. A mathematical model has thus been developed and proposed, as a guiding tool, for the designer to estimate the weight of main and auxiliary engines more accurately during the conceptual and preliminary design stage.

scholarly journals Uniform deformation design of outrigger braced skyscrapers: A simplified method for the preliminary design stage

Structures ◽  
2021 ◽  
Vol 31 ◽  
pp. 395-405
Author(s):  
Arsalan Alavi ◽  
Elena Mele ◽  
Reza Rahgozar ◽  
Ehsan Noroozinejad Farsangi ◽  
Izuru Takewaki ◽  
...  
Keyword(s):  
Design Stage ◽  
Preliminary Design ◽  
Uniform Deformation ◽  
Simplified Method ◽  
Preliminary Design Stage

scholarly journals Fatigue life prediction in a door hinge system under uni-axial and multi-axial loading conditions

2021 ◽  
Author(s):  
Sacheen Bekah
Keyword(s):  
Axial Loading ◽  
Fatigue Analysis ◽  
Design Stage ◽  
Fe Model ◽  
Preliminary Design ◽  
Standard Requirement ◽  
Ground Vehicle ◽  
Design Engineers ◽  
Door Hinge ◽  
Preliminary Design Stage

This thesis presents the use of Finite Element (FE) based fatigue analysis to locate the critical point of crack initiation and predict life in a door hinge system that is subjected to both uni-axial and multi-axial loading. The results are experimentally validated. The FE model is further used to obtain an optimum design per the standard requirement in the ground vehicle industry. The accuracy of the results showed that FE based fatigue analysis can be successfully employed to reduce costly and time-consuming experiments in the preliminary design stage. Numerical analysis also provides the product design engineers with substantial savings, enabling the testing of fewer prototypes.

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