The Experts below are selected from a list of 183 Experts worldwide ranked by ideXlab platform

P Krata - One of the best experts on this subject based on the ideXlab platform.

  • Ship’s rolling amplitude as a significant factor influencing liquid sloshing in partly filled tanks
    Journal of Konbin, 2020
    Co-Authors: P Krata, Wojciech Wawrzyński
    Abstract:

    The study considers ship’s rolling amplitude as one of the key parameters influencing liquid sloshing in partly filled tanks during sea voyage. This issue is strictly related to the safety of navigation matters and belongs to the group of non-linear hydrodynamic phenomena. The presented investigation is focused on the estimation of typical and extreme rolling amplitude of a vessel in terms of dynamic approach towards liquid motion onboard ships. The number of exemplary numerical simulations of liquid sloshing taking place in moving tanks is carried out and the Heeling Moment due to liquid sloshing is obtained.

  • Dynamic Component of Ship’s Heeling Moment due to Sloshing vs. IMO IS-Code Recommendations
    TransNav: International Journal on Marine Navigation and Safety of Sea Transportation, 2010
    Co-Authors: P Krata
    Abstract:

    The comparative study of the dynamic component of the Heeling Moment due to sloshing in ships’ partly filled tanks is presented in the paper. The characteristics of the Heeling Moment are obtained in the course of experimental tests and numerical simulations. The Heeling Moment is decomposed and the research is focused on the dynamic component resulting from liquid movement. The results of the research are compared to the computations performed in accordance with the IMO IS-Code recommendations. The need for amending of the intact ship stability assessment procedure is suggested.

  • dynamic component of ship s Heeling Moment due to sloshing vs imo is code recommendations
    TransNav: International Journal on Marine Navigation and Safety of Sea Transportation, 2010
    Co-Authors: P Krata
    Abstract:

    The comparative study of the dynamic component of the Heeling Moment due to sloshing in ships’ partly filled tanks is presented in the paper. The characteristics of the Heeling Moment are obtained in the course of experimental tests and numerical simulations. The Heeling Moment is decomposed and the research is focused on the dynamic component resulting from liquid movement. The results of the research are compared to the computations performed in accordance with the IMO IS-Code recommendations. The need for amending of the intact ship stability assessment procedure is suggested.

  • 3d cdf modeling of ship s Heeling Moment due to liquid sloshing in tanks a case study
    Journal of KONES, 2010
    Co-Authors: P Krata, J Jachowski
    Abstract:

    Modeling of liquid sloshing inside partly filled ships’ tanks can be carried out by a variety of methods. The simplest and perhaps the less reliable is a quasi-static approach which is, however, recommended in the Intact Stability Code by the International Maritime Organization. Hence the only advantage of the static estimation of liquid sloshing is simplicity of calculations, the research into the application of CFD (Computational Fluid Dynamics) was performed in Department of Ship Operation at Gdynia Maritime University. The paper presents results of numerical simulations of a liquid sloshing phenomenon performed by means of a code Fluent. The research was focused on a computation of the Heeling Moment affecting stability of a vessel, especially on the dynamic effects, which are omitted in obligatory intact ship’s stability regulations nowadays. The computed distributions of dynamic pressures on tank walls were carried out for large oscillation amplitude which is characteristic for stormy sea conditions. All the simulations were computed in 3D mode and they provide high accuracy results. A case study described in the paper enables realistic comparison of the results of CFD liquid sloshing simulations and the simple statics-based computations. The study reveals some weaknesses of the contemporary quasi-static approach towards the free surface effect and it might be the contribution to the more sophisticated estimation of the ship’s stability than it is achieved nowadays.

  • ship s Heeling Moment due to liquid sloshing in tanks 3d attitude
    Journal of KONES, 2009
    Co-Authors: J Jachowski, P Krata
    Abstract:

    The matter of the paper refers to the dynamic stability of a vessel as an important factor affecting her safety at seaway. Ship’s seakeeping behaviour, which comprises the notion of her stability, is one of the researched key issues leading to the increase in understanding of the safety qualifying factors. Liquid sloshing phenomenon is a result of partly filled tank motions. As a tank moves, it supplies the energy to induce and sustain the fluid motion. The dynamic behaviour of a vessel at seaway is considerably affected by the dynamics of free liquid surfaces, therefore the influence of fluid movement taking place in partly filled tanks on the safety of ship’s exploitation process is emphasized. The paper presents the results of the experimental research and the numerical simulation of the sloshing phenomenon. The research was focused on the computation of the Heeling Moment affecting the stability of a vessel, especially dynamic effects, which are omitted in obligatory intact ship’s stability regulations nowadays. The experiment performed in the course of the research was carried out in Department of Ship Operation at Gdynia Maritime University. The unique test apparatus was designed and built. It enables to measure dynamic pressures on model tank walls for large oscillation amplitudes, which are characteristic for stormy sea conditions. The numerical simulations of liquid sloshing phenomenon, took into account the viscosity of liquid and the turbulence of considered flows. All the simulations were computed in 3D mode and they provide high accuracy results. The spatial distribution of dynamic pressures on model tank walls enables computation of Heeling Moment due to liquid sloshing which affects ship’s stability. Further analysis of obtained Moments was carried out. The study may be the contribution to the more sophisticated estimation of the ship’s stability than it is achieved nowadays.

Przemyslaw Krata - One of the best experts on this subject based on the ideXlab platform.

  • Linear characteristics of the sloshing phenomenon for the purpose of on-board ship’s stability assessment
    Journal of Theoretical and Applied Mechanics, 2020
    Co-Authors: Przemyslaw Krata
    Abstract:

    The paper presents results of experimental research and numerical simulations of the sloshing phenomenon. The research was focused on computation of the Heeling Moment affecting stability of a vessel. The proposed linearisation enables application of the results to the assessment of the ship's stability. The dependence of the Heeling Moment upon localisation of a tank in the ship's hull is analysed. The Heeling Moment obtained in the course of the research was compared to the Moment computed in accordance with the Intact Stability Code requirements. The study may be a contribution to the more sophisticated estimation of the ship's stability than it is achieved nowadays.

  • analysis of dynamic Heeling Moment due to liquid sloshing in partly filled ship s tanks for realistic range of rolling periods a case study
    Journal of KONES. Powertrain and Transport, 2015
    Co-Authors: J Jachowski, Przemyslaw Krata, Wojciech Wawrzynski, Wojciech Wieckiewicz
    Abstract:

    Liquid sloshing phenomenon is a result of partly filled tank motions. As a tank moves, it supplies energy to induce and sustain a fluid motion. Both the liquid motion and its effects are called sloshing. The interaction between ship’s tank structure and water sloshing inside the tank consists in the constant transmission of energy. As the ship rolls, the walls of a partly filled tank induce the movement of water. Liquid sloshing phenomenon occurring in partly filled ships tanks directly affects the stability of the vessel. However, only static calculations are carried out onboard ships nowadays and static transfer of liquid weight is taken into account in the course of routine stability calculation and assessment. Since previous researches reveal the necessity of dynamic approach towards liquid movement onboard ships, the investigation is focused on problems related to time dependent wave-type phenomena. This aspect is omitted in the course of standard ship stability calculations. The set of numerical simulations of liquid sloshing taking place in moving tanks is carried out. Among many obtained characteristics, the Heeling Moment due to sloshing is emphasized and thoroughly investigated. The realistic range of possible metacentric heights and rolling periods is examined. The influence of ship’s rolling period on the Heeling Moment due to liquid sloshing is analyzed for one exemplary seagoing vessel as a case study. However, the conclusions can be generalized to some degree and comprise many other ships.

  • AN INVESTIGATION INTO THE INFLUENCE OF TANK FILLING LEVEL ON LIQUID SLOSHING EFFECTS ONBOARD SHIPS - STATIC AND DYNAMIC APPROACH
    Journal of KONES, 2015
    Co-Authors: Przemyslaw Krata, J Jachowski, Wojciech Wawrzyński, Wojciech Więckiewicz
    Abstract:

    Abstract The commonly discussed main features of maritime transport are usually its safety and effectiveness. One of the most critical features of seagoing ships related to her safety is stability influencing ship’s overall sea keeping performance. Vessels’ stability calculation and evaluation, made on-board nowadays, is based on the stability criteria published by the ship’s classification societies. According to the IMO recommendations, the righting lever curve should be corrected for the effect of free surfaces of liquids in tanks. IMO-recommended methods of free surface correction calculation consider the static attitude towards the liquid sloshing phenomenon only. They also do not consider the location of the tank within the hull of the ship and the location of a rolling axis. The more precise and more realistic approach towards liquid movement is complex analysis of liquid sloshing phenomenon. As liquid sloshing taking part in partly filled ship’s tanks is an important element affecting safety of maritime transportation process, there is a need for detailed analyses related to crucial parameters of the considered phenomenon. The paper is focused on an influence of tank’s filling level on effects of aroused and sustained movement of ballast water, fuel and other liquids carried onboard ships. Both static and dynamic approaches towards the problem are utilized. The analytical methods for liquid weight transfer calculation and numerical simulations of the liquid sloshing phenomenon are applied. The simulations of liquid sloshing are based on Reynolds-averaged Navier-Stockes equation and they take into account the viscosity of liquid. The resultant Heeling Moment is decomposed into components enabling extraction of dynamical component differentiating the applied method from old static ones. The results of the study contribute to more precise ship safety evaluation.

  • A Method of Assessment of the Liquid Sloshing Impact on Ship Transverse Stability
    TransNav: International Journal on Marine Navigation and Safety of Sea Transportation, 2014
    Co-Authors: Przemyslaw Krata
    Abstract:

    Liquid sloshing phenomenon taking place in partly filled ships’ tanks directly affects the stability of a vessel. However, only static calculations are carried out onboard ships nowadays and static transfer of liquid weight is taken into account in the course of routine stability calculation. The paper is focused on a dynamic Heeling Moment due to liquid sloshing in tanks onboard ships. The set of numerical simulations of liquid sloshing taking place in moving tanks is carried out. The realistic range of geometric parameters is taken into account. The conducted CFD simulations are experimentally verified. Finally, the method of an assessment of the liquid sloshing impact on ship transverse stability is worked out. The key point of the method is a dynamic coefficient describing relation of the researched dynamic Heeling Moment and the quasi-static one in terms of dynamic stability of a vessel which is related to the weather criterion of ship stability assessment.

  • The Impact of Sloshing Liquids on Ship Stability for Various Dimensions of Partly Filled Tanks
    TransNav: International Journal on Marine Navigation and Safety of Sea Transportation, 2013
    Co-Authors: Przemyslaw Krata
    Abstract:

    Liquid sloshing phenomenon taking place in partly filled ships’ tanks directly affects the stability of a vessel. However, only static calculations are carried out onboard ships nowadays and static transfer of liquid weight is taken into account in the course of routine stability calculation. The paper is focused on a dynamic Heeling Moment due to liquid sloshing in tanks onboard ships. A number of numerical simulations of liquid sloshing taking place in a moving tank is carried out. The wide range of ship’s tanks is taken into account. The conducted CFD simulations are experimentally verified. Finally, the method of an assessment of the liquid sloshing impact on ship transverse stability is worked out. The key point of the method is a dynamic coefficient describing relation of the researched dynamic Heeling Moment and the quasi-static one in terms of dynamic stability of a vessel which is related to the weather criterion of ship stability assessment.

J Jachowski - One of the best experts on this subject based on the ideXlab platform.

  • analysis of dynamic Heeling Moment due to liquid sloshing in partly filled ship s tanks for realistic range of rolling periods a case study
    Journal of KONES. Powertrain and Transport, 2015
    Co-Authors: J Jachowski, Przemyslaw Krata, Wojciech Wawrzynski, Wojciech Wieckiewicz
    Abstract:

    Liquid sloshing phenomenon is a result of partly filled tank motions. As a tank moves, it supplies energy to induce and sustain a fluid motion. Both the liquid motion and its effects are called sloshing. The interaction between ship’s tank structure and water sloshing inside the tank consists in the constant transmission of energy. As the ship rolls, the walls of a partly filled tank induce the movement of water. Liquid sloshing phenomenon occurring in partly filled ships tanks directly affects the stability of the vessel. However, only static calculations are carried out onboard ships nowadays and static transfer of liquid weight is taken into account in the course of routine stability calculation and assessment. Since previous researches reveal the necessity of dynamic approach towards liquid movement onboard ships, the investigation is focused on problems related to time dependent wave-type phenomena. This aspect is omitted in the course of standard ship stability calculations. The set of numerical simulations of liquid sloshing taking place in moving tanks is carried out. Among many obtained characteristics, the Heeling Moment due to sloshing is emphasized and thoroughly investigated. The realistic range of possible metacentric heights and rolling periods is examined. The influence of ship’s rolling period on the Heeling Moment due to liquid sloshing is analyzed for one exemplary seagoing vessel as a case study. However, the conclusions can be generalized to some degree and comprise many other ships.

  • AN INVESTIGATION INTO THE INFLUENCE OF TANK FILLING LEVEL ON LIQUID SLOSHING EFFECTS ONBOARD SHIPS - STATIC AND DYNAMIC APPROACH
    Journal of KONES, 2015
    Co-Authors: Przemyslaw Krata, J Jachowski, Wojciech Wawrzyński, Wojciech Więckiewicz
    Abstract:

    Abstract The commonly discussed main features of maritime transport are usually its safety and effectiveness. One of the most critical features of seagoing ships related to her safety is stability influencing ship’s overall sea keeping performance. Vessels’ stability calculation and evaluation, made on-board nowadays, is based on the stability criteria published by the ship’s classification societies. According to the IMO recommendations, the righting lever curve should be corrected for the effect of free surfaces of liquids in tanks. IMO-recommended methods of free surface correction calculation consider the static attitude towards the liquid sloshing phenomenon only. They also do not consider the location of the tank within the hull of the ship and the location of a rolling axis. The more precise and more realistic approach towards liquid movement is complex analysis of liquid sloshing phenomenon. As liquid sloshing taking part in partly filled ship’s tanks is an important element affecting safety of maritime transportation process, there is a need for detailed analyses related to crucial parameters of the considered phenomenon. The paper is focused on an influence of tank’s filling level on effects of aroused and sustained movement of ballast water, fuel and other liquids carried onboard ships. Both static and dynamic approaches towards the problem are utilized. The analytical methods for liquid weight transfer calculation and numerical simulations of the liquid sloshing phenomenon are applied. The simulations of liquid sloshing are based on Reynolds-averaged Navier-Stockes equation and they take into account the viscosity of liquid. The resultant Heeling Moment is decomposed into components enabling extraction of dynamical component differentiating the applied method from old static ones. The results of the study contribute to more precise ship safety evaluation.

  • Dynamic Heeling Moment Due to Liquid Sloshing in a Rectangular Tank of Different Dimensions and Elevation in Ship’S Hull / Dynamiczny Moment Przechylający Od Swobodnych Powierzchni Cieczy W Prostokątnym Zbiorniku Okrętowym O Różnych Wymiarach I Lokal
    Journal of Konbin, 2012
    Co-Authors: Przemyslaw Krata, J Jachowski
    Abstract:

    Abstract Liquid sloshing phenomenon taking place in partly filled ships’ tanks directly affects the stability of a vessel and her safety on seaway, however, only static calculations are carried out onboard ships nowadays. The presented investigation is focused on dynamic approach towards liquid motion onboard ships. The set of numerical simulations of liquid sloshing taking place in moving tanks is carried out in terms of tank’s dimensions and its elevation within ship’s hull. A number of characteristics of the Heeling Moment due to liquid sloshing is obtained and analyzed.

  • 3d cdf modeling of ship s Heeling Moment due to liquid sloshing in tanks a case study
    Journal of KONES, 2010
    Co-Authors: P Krata, J Jachowski
    Abstract:

    Modeling of liquid sloshing inside partly filled ships’ tanks can be carried out by a variety of methods. The simplest and perhaps the less reliable is a quasi-static approach which is, however, recommended in the Intact Stability Code by the International Maritime Organization. Hence the only advantage of the static estimation of liquid sloshing is simplicity of calculations, the research into the application of CFD (Computational Fluid Dynamics) was performed in Department of Ship Operation at Gdynia Maritime University. The paper presents results of numerical simulations of a liquid sloshing phenomenon performed by means of a code Fluent. The research was focused on a computation of the Heeling Moment affecting stability of a vessel, especially on the dynamic effects, which are omitted in obligatory intact ship’s stability regulations nowadays. The computed distributions of dynamic pressures on tank walls were carried out for large oscillation amplitude which is characteristic for stormy sea conditions. All the simulations were computed in 3D mode and they provide high accuracy results. A case study described in the paper enables realistic comparison of the results of CFD liquid sloshing simulations and the simple statics-based computations. The study reveals some weaknesses of the contemporary quasi-static approach towards the free surface effect and it might be the contribution to the more sophisticated estimation of the ship’s stability than it is achieved nowadays.

  • ship s Heeling Moment due to liquid sloshing in tanks 3d attitude
    Journal of KONES, 2009
    Co-Authors: J Jachowski, P Krata
    Abstract:

    The matter of the paper refers to the dynamic stability of a vessel as an important factor affecting her safety at seaway. Ship’s seakeeping behaviour, which comprises the notion of her stability, is one of the researched key issues leading to the increase in understanding of the safety qualifying factors. Liquid sloshing phenomenon is a result of partly filled tank motions. As a tank moves, it supplies the energy to induce and sustain the fluid motion. The dynamic behaviour of a vessel at seaway is considerably affected by the dynamics of free liquid surfaces, therefore the influence of fluid movement taking place in partly filled tanks on the safety of ship’s exploitation process is emphasized. The paper presents the results of the experimental research and the numerical simulation of the sloshing phenomenon. The research was focused on the computation of the Heeling Moment affecting the stability of a vessel, especially dynamic effects, which are omitted in obligatory intact ship’s stability regulations nowadays. The experiment performed in the course of the research was carried out in Department of Ship Operation at Gdynia Maritime University. The unique test apparatus was designed and built. It enables to measure dynamic pressures on model tank walls for large oscillation amplitudes, which are characteristic for stormy sea conditions. The numerical simulations of liquid sloshing phenomenon, took into account the viscosity of liquid and the turbulence of considered flows. All the simulations were computed in 3D mode and they provide high accuracy results. The spatial distribution of dynamic pressures on model tank walls enables computation of Heeling Moment due to liquid sloshing which affects ship’s stability. Further analysis of obtained Moments was carried out. The study may be the contribution to the more sophisticated estimation of the ship’s stability than it is achieved nowadays.

Wojciech Wawrzyński - One of the best experts on this subject based on the ideXlab platform.

  • Ship’s rolling amplitude as a significant factor influencing liquid sloshing in partly filled tanks
    Journal of Konbin, 2020
    Co-Authors: P Krata, Wojciech Wawrzyński
    Abstract:

    The study considers ship’s rolling amplitude as one of the key parameters influencing liquid sloshing in partly filled tanks during sea voyage. This issue is strictly related to the safety of navigation matters and belongs to the group of non-linear hydrodynamic phenomena. The presented investigation is focused on the estimation of typical and extreme rolling amplitude of a vessel in terms of dynamic approach towards liquid motion onboard ships. The number of exemplary numerical simulations of liquid sloshing taking place in moving tanks is carried out and the Heeling Moment due to liquid sloshing is obtained.

  • AN INVESTIGATION INTO THE INFLUENCE OF TANK FILLING LEVEL ON LIQUID SLOSHING EFFECTS ONBOARD SHIPS - STATIC AND DYNAMIC APPROACH
    Journal of KONES, 2015
    Co-Authors: Przemyslaw Krata, J Jachowski, Wojciech Wawrzyński, Wojciech Więckiewicz
    Abstract:

    Abstract The commonly discussed main features of maritime transport are usually its safety and effectiveness. One of the most critical features of seagoing ships related to her safety is stability influencing ship’s overall sea keeping performance. Vessels’ stability calculation and evaluation, made on-board nowadays, is based on the stability criteria published by the ship’s classification societies. According to the IMO recommendations, the righting lever curve should be corrected for the effect of free surfaces of liquids in tanks. IMO-recommended methods of free surface correction calculation consider the static attitude towards the liquid sloshing phenomenon only. They also do not consider the location of the tank within the hull of the ship and the location of a rolling axis. The more precise and more realistic approach towards liquid movement is complex analysis of liquid sloshing phenomenon. As liquid sloshing taking part in partly filled ship’s tanks is an important element affecting safety of maritime transportation process, there is a need for detailed analyses related to crucial parameters of the considered phenomenon. The paper is focused on an influence of tank’s filling level on effects of aroused and sustained movement of ballast water, fuel and other liquids carried onboard ships. Both static and dynamic approaches towards the problem are utilized. The analytical methods for liquid weight transfer calculation and numerical simulations of the liquid sloshing phenomenon are applied. The simulations of liquid sloshing are based on Reynolds-averaged Navier-Stockes equation and they take into account the viscosity of liquid. The resultant Heeling Moment is decomposed into components enabling extraction of dynamical component differentiating the applied method from old static ones. The results of the study contribute to more precise ship safety evaluation.

  • Ship’S Rolling Amplitude as a Significant Factor Influencing Liquid Sloshing in Partly Filled Tanks / Amplituda Kołysań Statku Jako Istotny Parametr W Badaniach Zjawiska Sloshingu W Niepełnych Zbiornikach Okrętowych
    Journal of Konbin, 2012
    Co-Authors: Przemyslaw Krata, Wojciech Wawrzyński
    Abstract:

    Abstract The study considers ship’s rolling amplitude as one of the key parameters influencing liquid sloshing in partly filled tanks during sea voyage. This issue is strictly related to the safety of navigation matters and belongs to the group of non-linear hydrodynamic phenomena. The presented investigation is focused on the estimation of typical and extreme rolling amplitude of a vessel in terms of dynamic approach towards liquid motion onboard ships. The number of exemplary numerical simulations of liquid sloshing taking place in moving tanks is carried out and the Heeling Moment due to liquid sloshing is obtained.

N. A. Vel’magina - One of the best experts on this subject based on the ideXlab platform.