Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "method of calculation" wg kryterium: Wszystkie pola


Wyświetlanie 1-6 z 6
Tytuł:
An approximate method for calculation of mean statistical value of ship service speed on a given shipping line, useful in preliminary design stage
Autorzy:
Żelazny, K.
Powiązania:
https://bibliotekanauki.pl/articles/259679.pdf
Data publikacji:
2015
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
service speed
shipping lines
preliminary design
Opis:
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.
Źródło:
Polish Maritime Research; 2015, 1; 28-35
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A fatigue life calculation method for structural elements made of D16CzATW aluminium alloy
Autorzy:
Szala, J.
Szala, G.
Powiązania:
https://bibliotekanauki.pl/articles/258694.pdf
Data publikacji:
2010
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
fatigue life
tructutral elements
D16CzATW aluminium alloy
Opis:
In the calculating of fatigue life of structural elements the methods based on hypotheses of fatigue damage summation are commonly applied. In using the methods, apart from choice of an appropriate hypothesis, it is necessary to know a loading spectrum which usually constitutes a set of sinusoidal cycles of variable parameters (Sa, Sm), as well as fatigue characteristics in the form of Wöhler fatigue diagram, as a rule. Knowledge of the above mentioned data is low during structural design process as designed material objects and possibility of performing measurements are lacking. Hence in this work a calculation method of fatigue life of structural elements, based on the relations between fatigue life diagrams determined in constant-amplitude conditions (Wöhler diagrams) and those obtained under programmed or random loads, is described. The proposed method was experimentally verified by using results of fatigue tests on structural elements made of D16CzATW aluminium alloy.
Źródło:
Polish Maritime Research; 2010, 3; 8-17
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Boundary element method applied to added mass coefficient calculation of the skewed marine propellers
Autorzy:
Yari, E.
Ghassemi, H.
Powiązania:
https://bibliotekanauki.pl/articles/260213.pdf
Data publikacji:
2016
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
added mass coefficient
boundary element method
skew marine propeller
Opis:
The paper mainly aims to study computation of added mass coefficients for marine propellers. A three-dimensional boundary element method (BEM) is developed to predict the propeller added mass and moment of inertia coefficients. Actually, only few experimental data sets are available as the validation reference. Here the method is validated with experimental measurements of the B-series marine propeller. The behavior of the added mass coefficients predicted based on variation of geometric and flow parameters of the propeller is calculated and analyzed. BEM is more accurate in obtaining added mass coefficients than other fast numerical methods. All added mass coefficients are nondimensionalized by fluid density, propeller diameter, and rotational velocity. The obtained results reveal that the diameter, expanded area ratio, and thickness have dominant influence on the increase of the added mass coefficients.
Źródło:
Polish Maritime Research; 2016, 2; 25-31
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A method to assess transverse vibration energy of ship propeller shaft for diagnostic purposes
Autorzy:
Korczewski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/259221.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
rotational mechanical system
propeller shaft transverse vibration energy
calculation model
Opis:
The article discusses a key problem of ship propulsion system vibration diagnostics, which concerns assessing this part of mechanical energy transmitted from the main engine to the ship propeller which is dissipated due to propeller shaft vibration. A simplified calculation model is proposed which allows the total energy of the generated torsional vibration to be assessed from the shaft deflection amplitude measured at the mind-span point between the supports. To verify the developed model, pilot tests were performed on the laboratory rotational mechanical system test rig. In those tests, cyclic bending moment was applied to a unified (cylindrical) material sample, which modelled, at an appropriate scale, structural and functional properties of a real propeller shaft.
Źródło:
Polish Maritime Research; 2017, 4; 102-107
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hybrid finite element method development for offshore structures’ calculation with the implementation of industry standards
Autorzy:
Łubiński, Jacek
Olszewski, Henryk
Powiązania:
https://bibliotekanauki.pl/articles/260070.pdf
Data publikacji:
2019
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
offshore structures
design calculations
sea loading
stress evaluation
FEM
Opis:
In the design process of offshore steel structures, it is typical to employ commercial calculation codes in which simulation and evaluation of results are performed on the basis of the available standards (e.g. API, DNV, Lloyds). The modeling and solution rely on finite element methods and cover the simulation of the structure’s properties along with the influence of the marine environment – sea currents, wave and wind loading, as well as the influence of vibrations, buoyancy and accompanying mass of water. Both commercial and open source mathematical modeling software which is available nowadays allows for cost effective and flexible implementation of advanced models for offshore industrial structures with high level of credibility and safety. The models can be built to suit task-specific requirements and evaluated on the basis of the selected criterial system best suited to the needs of the customer. Examples of methodology for environmental and structural model development are presented, along with simulation results covering a wide scope of data, ranging from stress and deformation to resonant characteristics and issues of technological feasibility.
Źródło:
Polish Maritime Research; 2019, 4; 90-100
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Calculation method for flow boiling and flow condensation of R134a and R1234yf in conventional and small diameter channels
Autorzy:
Mikielewicz, D.
Jakubowska, B.
Powiązania:
https://bibliotekanauki.pl/articles/259535.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
heat transfer coefficient
flow boiling
conventional channels
minichannels
Opis:
The paper presents the results of calculations performed using the authors’ model to predict the heat transfer coefficient during flow boiling for two refrigerants R134a and R1234yf. The experimental data from various past studies have been collected and the calculations have been conducted for the full range of quality variation and a wide range of mass velocity. The aim of the study was to test the sensitivity of the in-house flow boiling and flow condensation model. The importance of taking into account the surface tension as the parameter exhibiting its importance in case of the flow in minichannels, as well as the influence of the reduced pressure were analysed. The obtained numerical results show good consistency with those recorded in the experiments.
Źródło:
Polish Maritime Research; 2017, S 1; 141-148
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-6 z 6

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies