Sailing in oblique stern waves causes a ship to make sharp turns and uncontrollable course deviation, which is accompanied by a large heel and sometimes leads to capsizing. Studying the control algorithm in oblique stern waves is imperative because an excellent controller scheme can improve the ship’s course-keeping stability. This paper uses the Maneuvering Modelling Group (MMG) method based on hydrodynamic derivatives and the Computational Fluid Dynamics (CFD)-based self-navigation simulation to simulate ship navigation in waves. This study examines the effect of proportion-integral-derivative (PID) controller schemes on the stability of course maintenance based on hydrodynamic derivatives and 3DOF MMG methods. Then, the optimized PID control parameters are used to simulate the ship’s 6DOF self-propulsion navigation in oblique waves using the CFD method. The nonlinear phenomena during the process, such as side-hull emergency, slamming, and green water, are considered. This study found that the range of the control bandwidth should be optimized based on the ship's heading and wave parameters.
在斜尾波中航行会使船舶发生急转弯和无法控制的航向偏离，并伴有较大的后跟，有时会导致倾覆。研究斜尾波下的控制算法是十分必要的，因为一个好的控制方案可以提高船舶的航向保持稳定性。本文采用基于水动力导数的机动建模组(MMG)方法和基于计算流体力学(CFD)的自航仿真方法对船舶在波浪中的航行进行了仿真。本文研究了比例-积分-导数(PID)控制方案对基于流体动力导数和3d - of - MMG方法的航向维持稳定性的影响。然后，利用优化后的PID控制参数，利用CFD方法对船舶在斜波中进行了6DOF自推进航行仿真。在此过程中，考虑了舷侧急变、轰击、绿水等非线性现象。研究发现，控制带宽的范围应根据船舶航向和波浪参数进行优化。
{"title":"The effect of PID control scheme on the course-keeping of ship in oblique stern waves","authors":"Yunbo Li","doi":"10.21278/brod74408","DOIUrl":"https://doi.org/10.21278/brod74408","url":null,"abstract":"Sailing in oblique stern waves causes a ship to make sharp turns and uncontrollable course deviation, which is accompanied by a large heel and sometimes leads to capsizing. Studying the control algorithm in oblique stern waves is imperative because an excellent controller scheme can improve the ship’s course-keeping stability. This paper uses the Maneuvering Modelling Group (MMG) method based on hydrodynamic derivatives and the Computational Fluid Dynamics (CFD)-based self-navigation simulation to simulate ship navigation in waves. This study examines the effect of proportion-integral-derivative (PID) controller schemes on the stability of course maintenance based on hydrodynamic derivatives and 3DOF MMG methods. Then, the optimized PID control parameters are used to simulate the ship’s 6DOF self-propulsion navigation in oblique waves using the CFD method. The nonlinear phenomena during the process, such as side-hull emergency, slamming, and green water, are considered. This study found that the range of the control bandwidth should be optimized based on the ship's heading and wave parameters.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135735141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
One of the crucial aspects of the conceptual design of a stepped planing hull is the prediction of its performance. To improve performance, the prediction of total resistance must become more accurate. In the field of research, both towing tank experiments and numerical analysis may be used to achieve this goal. In this study, experiments were conducted initially to investigate total resistance of a relatively high-speed craft without a transverse step. Later, numerical computations were carried out to validate the experimental results. After it was determined that the test results and CFD methods were in good agreement, the experimental method continued to investigate the resistance properties of the hull with four different configurations to evaluate the optimal longitudinal position of a single transverse step. The ideal longitudinal position of the single transverse step was evaluated based on a similar relatively high-speed hull with a velocity of up to beam Froude number (FrB) 2.56 in this study, focusing on the FrB range between 2.30 and 2.45.
{"title":"Investigation of the optimum longitudinal single transverse step location for a high-speed craft","authors":"A. Avci, B. Barlas","doi":"10.21278/brod74303","DOIUrl":"https://doi.org/10.21278/brod74303","url":null,"abstract":"One of the crucial aspects of the conceptual design of a stepped planing hull is the prediction of its performance. To improve performance, the prediction of total resistance must become more accurate. In the field of research, both towing tank experiments and numerical analysis may be used to achieve this goal. In this study, experiments were conducted initially to investigate total resistance of a relatively high-speed craft without a transverse step. Later, numerical computations were carried out to validate the experimental results. After it was determined that the test results and CFD methods were in good agreement, the experimental method continued to investigate the resistance properties of the hull with four different configurations to evaluate the optimal longitudinal position of a single transverse step. The ideal longitudinal position of the single transverse step was evaluated based on a similar relatively high-speed hull with a velocity of up to beam Froude number (FrB) 2.56 in this study, focusing on the FrB range between 2.30 and 2.45.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45614808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Due to the complex fluid interference between outrigger and main hull, it is difficult to predict the trimaran load fluctuation accurately in different marine environments. Therefore, a time-domain Rankine method is developed to improve the accuracy of trimaran load prediction. This method successfully adds the nonlinear load components in time-domain load simulation by taking into account the factors such as instantaneous hull wetted surface, steady ship waves, green wave and slamming. Additionally, the nonlinear growth of green wave and slamming is also observed at outrigger and wet deck, with the increasing of speeds and wave heights. Finally, the relatively smaller errors in the Rankine method are confirmed by comparison with the values from a trimaran model test and linear time-domain load prediction method. Furthermore, the weakly nonlinear Rankine method is considered to be more suitable for trimaran load prediction under harsh marine environment.
{"title":"Numerical study of trimaran wave load based on time-domain Rankine method","authors":"Haoyun Tang, Q. Wan, H. Ren","doi":"10.21278/brod74306","DOIUrl":"https://doi.org/10.21278/brod74306","url":null,"abstract":"Due to the complex fluid interference between outrigger and main hull, it is difficult to predict the trimaran load fluctuation accurately in different marine environments. Therefore, a time-domain Rankine method is developed to improve the accuracy of trimaran load prediction. This method successfully adds the nonlinear load components in time-domain load simulation by taking into account the factors such as instantaneous hull wetted surface, steady ship waves, green wave and slamming. Additionally, the nonlinear growth of green wave and slamming is also observed at outrigger and wet deck, with the increasing of speeds and wave heights. Finally, the relatively smaller errors in the Rankine method are confirmed by comparison with the values from a trimaran model test and linear time-domain load prediction method. Furthermore, the weakly nonlinear Rankine method is considered to be more suitable for trimaran load prediction under harsh marine environment.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46067073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper presents a fast alternative optimization method for developing a reliable optimal controller that can handle system model parameter uncertainties. The source of uncertainty in this study is identified as hydrodynamic coefficients, which are prone to errors due to the challenges involved in obtaining accurate values. The proposed optimization method utilizes a complex nonlinear ship model provided by Maneuver Modelling Group (MMG) as the reference for the ship motion model. The optimization process is divided into two stages: a blind search followed by bisection optimization, to obtain a robust optimal controller. To demonstrate the effectiveness of the proposed approach, system response analysis and practical tests were performed on Step, M-Turn, and Doublet maneuvers. The results show that the controller parameters obtained from the proposed optimization method are capable of achieving high success rates in controlling a system with uncertain parameters.
{"title":"Robust optimal control of a nonlinear surface vessel model with parametric uncertainties","authors":"Ahmad Irham Jambak, I. Bayezit","doi":"10.21278/brod74307","DOIUrl":"https://doi.org/10.21278/brod74307","url":null,"abstract":"This paper presents a fast alternative optimization method for developing a reliable optimal controller that can handle system model parameter uncertainties. The source of uncertainty in this study is identified as hydrodynamic coefficients, which are prone to errors due to the challenges involved in obtaining accurate values. The proposed optimization method utilizes a complex nonlinear ship model provided by Maneuver Modelling Group (MMG) as the reference for the ship motion model. The optimization process is divided into two stages: a blind search followed by bisection optimization, to obtain a robust optimal controller. To demonstrate the effectiveness of the proposed approach, system response analysis and practical tests were performed on Step, M-Turn, and Doublet maneuvers. The results show that the controller parameters obtained from the proposed optimization method are capable of achieving high success rates in controlling a system with uncertain parameters.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44904752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To evaluate the time-domain positioning performance of arctic marine structures, it is necessary to generate an ice load appropriate for the current position and heading of the structure. The position and orientation angle of a floating body continuously change with time. Therefore, an ice load is required for any attitude in the time-domain simulation. In this study, we present a fundamental technique for analyzing ice loads in the frequency domain based on data measured at various angles in the ice-water tank experiment. We perform spectral analysis instead of general FFT to analyze the ice load, which has the characteristics of a random signal. To generate the necessary ice load in the time domain, we must first interpolate the measured data in the frequency domain. Using the Blackman-Tukey method, we estimate the spectrum for the measured data, then process the data to generate the training set required for machine learning. Based on the results, we perform regression analysis by applying four representative techniques, including linear regression, random forest, or neural network, and compare the results with MSE. The deep neural network method performed best, but we provide further discussion for each model.
{"title":"A comparison of regression models for the ice loads measured during the ice tank test","authors":"Seung Jae Lee, K. Jung, Namkug Ku, Jaeyong Lee","doi":"10.21278/brod74301","DOIUrl":"https://doi.org/10.21278/brod74301","url":null,"abstract":"To evaluate the time-domain positioning performance of arctic marine structures, it is necessary to generate an ice load appropriate for the current position and heading of the structure. The position and orientation angle of a floating body continuously change with time. Therefore, an ice load is required for any attitude in the time-domain simulation. In this study, we present a fundamental technique for analyzing ice loads in the frequency domain based on data measured at various angles in the ice-water tank experiment. We perform spectral analysis instead of general FFT to analyze the ice load, which has the characteristics of a random signal. To generate the necessary ice load in the time domain, we must first interpolate the measured data in the frequency domain. Using the Blackman-Tukey method, we estimate the spectrum for the measured data, then process the data to generate the training set required for machine learning. Based on the results, we perform regression analysis by applying four representative techniques, including linear regression, random forest, or neural network, and compare the results with MSE. The deep neural network method performed best, but we provide further discussion for each model.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43985219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, exact hydrostatic particulars equations for the centre of buoyancy curve and metacentric locus curve are given for rectangular cross section using quadratic functions. Those equations have not been given for the hyperbola range of the heel angles so far, and here it is done by using basic quadratic functions and their horizontally symmetric immersion shapes, with two new methods defined: 1. Rotation of basic cross section shapes, and 2. Hydrostatic cross section area complement method that uses homothety or scaling properties of emerged and immersed areas of the rectangular cross section. Observed metacentric curve for rectangle consists of semi-cubic parabolas and Lamé curve with 2/3 exponent and negative sign, resulting in the cusp discontinuities in the symmetry of those functions definition. In order to achieve above, two theorems are given: the theorem about scaling using hydrostatic cross section area complement and the theorem about parallelism of centre of buoyancy tangents with waterlines. After non-dimensional bounds are given for the existence of the swallowtail discontinuity of metacentric curve for rectangular cross section in the Part 1 of this paper, the proof of its position in the symmetry of rectangle vertex angle is given in this Part 2 of the paper, thus confirming its position from theory.
{"title":"Re-examination of centre of buoyancy curve and its evolute for rectangular cross section, Part 2: Using quadratic functions","authors":"D. Ban","doi":"10.21278/brod74302","DOIUrl":"https://doi.org/10.21278/brod74302","url":null,"abstract":"In this paper, exact hydrostatic particulars equations for the centre of buoyancy curve and metacentric locus curve are given for rectangular cross section using quadratic functions. Those equations have not been given for the hyperbola range of the heel angles so far, and here it is done by using basic quadratic functions and their horizontally symmetric immersion shapes, with two new methods defined: 1. Rotation of basic cross section shapes, and 2. Hydrostatic cross section area complement method that uses homothety or scaling properties of emerged and immersed areas of the rectangular cross section. Observed metacentric curve for rectangle consists of semi-cubic parabolas and Lamé curve with 2/3 exponent and negative sign, resulting in the cusp discontinuities in the symmetry of those functions definition. In order to achieve above, two theorems are given: the theorem about scaling using hydrostatic cross section area complement and the theorem about parallelism of centre of buoyancy tangents with waterlines. After non-dimensional bounds are given for the existence of the swallowtail discontinuity of metacentric curve for rectangular cross section in the Part 1 of this paper, the proof of its position in the symmetry of rectangle vertex angle is given in this Part 2 of the paper, thus confirming its position from theory.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49313526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A competitive advantage over other shipyards is extremely important in the high-stake shipbuilding industry. Typically, a competitiveness analysis of a shipyard measures productivity based on specific parameters, such as tonnes or compensated gross tons produced per consumed working hour. The authors of this paper consider identifying the technological level required to achieve this productivity as essential, including other information relevant for the shipbuilding process. Therefore, a methodology for determining the technological level of shipyards is proposed based on defined criteria and a structured evaluation. The criteria were devised and structured hierarchically. The methodology also offers company management a solution for continuous monitoring for improving shipyard design and production processes.
{"title":"The shipyard technological level evaluation methodology","authors":"Rajko Rubeša, M. Hadjina, T. Matulja, D. Bolf","doi":"10.21278/brod74305","DOIUrl":"https://doi.org/10.21278/brod74305","url":null,"abstract":"A competitive advantage over other shipyards is extremely important in the high-stake shipbuilding industry. Typically, a competitiveness analysis of a shipyard measures productivity based on specific parameters, such as tonnes or compensated gross tons produced per consumed working hour. The authors of this paper consider identifying the technological level required to achieve this productivity as essential, including other information relevant for the shipbuilding process. Therefore, a methodology for determining the technological level of shipyards is proposed based on defined criteria and a structured evaluation. The criteria were devised and structured hierarchically. The methodology also offers company management a solution for continuous monitoring for improving shipyard design and production processes.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44359453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Liu Liang, Zhang Baoji, Zhang Hao, Hailin Tang, Weijie Wang
Fiber-reinforced composites offer the benefits of high strength, high stiffness, lightweight, superior damping performance, and great design capability when compared to metal. The rigidity characteristics of the composite laminate in different directions may be adjusted to meet the requirements of the application by using appropriate materials and arranging the lay-up sequence. As a result, the purpose of this work is to explore the influence of lay-up type on propeller performance in terms of both hydrodynamic and structural performance. A transient fluid-structure interaction (FSI) algorithm based on the finite element method (FEM) combined with the computational fluid dynamics (CFD) technique is developed and used for the analysis of composite propellers. The hydrodynamic performance of the propeller is compared to that of a metallic material. Propeller propulsion efficiency, structural deformation, equivalent stress, and damage performance of different lay-up options under three different operating situations are compared. In addition, it is presented a parametric optimization approach to get the most appropriate lay-up program for composite blades with the best hydrodynamic properties and structural performance.
{"title":"Hydrodynamic performance optimization of marine propellers based on fluid-structure coupling","authors":"Liu Liang, Zhang Baoji, Zhang Hao, Hailin Tang, Weijie Wang","doi":"10.21278/brod74308","DOIUrl":"https://doi.org/10.21278/brod74308","url":null,"abstract":"Fiber-reinforced composites offer the benefits of high strength, high stiffness, lightweight, superior damping performance, and great design capability when compared to metal. The rigidity characteristics of the composite laminate in different directions may be adjusted to meet the requirements of the application by using appropriate materials and arranging the lay-up sequence. As a result, the purpose of this work is to explore the influence of lay-up type on propeller performance in terms of both hydrodynamic and structural performance. A transient fluid-structure interaction (FSI) algorithm based on the finite element method (FEM) combined with the computational fluid dynamics (CFD) technique is developed and used for the analysis of composite propellers. The hydrodynamic performance of the propeller is compared to that of a metallic material. Propeller propulsion efficiency, structural deformation, equivalent stress, and damage performance of different lay-up options under three different operating situations are compared. In addition, it is presented a parametric optimization approach to get the most appropriate lay-up program for composite blades with the best hydrodynamic properties and structural performance.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42722543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Inland waterways vessels (IWV) have no mandatory regulations regarding their energy efficiency, as sea-going ships have. So far, there are just two proposed design energy efficiency evaluation methods, both based on IMO EEDI approach and data on EU inland navigation. Operational indicators and real-time navigation measurements from available literature do not exist. Therefore, this paper aims to introduce the energy efficiency in operation (EEO), assessed for the typical Danube cargo vessel. Firstly, an operational profile is acquired by tracking the vessel’s voyages, and by identifying actual constraints of each sector the vessel has sailed during the designated time. Secondly, EEO is incorporated within two available methods and calculated based on acquired operational data considering different navigational conditions. The paper shows how the energy efficiency vastly depends on variables such as water depth, current speed, draught, deadweight, river constraints. Analysis is performed for the most employed month of the vessel navigation, and annually. Depending on water level scenarios and during the selected month of sailing, the total amount of CO2 emitted is estimated to be between 22.7 t and 29.9 t, while the necessary average speed reduction (i.e., slow steaming) per sectoral voyage for the requirement compliance is calculated to be in between 4.8%-26%. Slow steaming is assessed to extend the time of voyage for 6.1-10.7 hours on monthly basis and 49-87 hours annually.
{"title":"Inland waterway cargo vessel energy efficiency in operation","authors":"M. Kalajdžić, Matija Vasilev, N. Momčilović","doi":"10.21278/brod74304","DOIUrl":"https://doi.org/10.21278/brod74304","url":null,"abstract":"Inland waterways vessels (IWV) have no mandatory regulations regarding their energy efficiency, as sea-going ships have. So far, there are just two proposed design energy efficiency evaluation methods, both based on IMO EEDI approach and data on EU inland navigation. Operational indicators and real-time navigation measurements from available literature do not exist. Therefore, this paper aims to introduce the energy efficiency in operation (EEO), assessed for the typical Danube cargo vessel. Firstly, an operational profile is acquired by tracking the vessel’s voyages, and by identifying actual constraints of each sector the vessel has sailed during the designated time. Secondly, EEO is incorporated within two available methods and calculated based on acquired operational data considering different navigational conditions. The paper shows how the energy efficiency vastly depends on variables such as water depth, current speed, draught, deadweight, river constraints. Analysis is performed for the most employed month of the vessel navigation, and annually. Depending on water level scenarios and during the selected month of sailing, the total amount of CO2 emitted is estimated to be between 22.7 t and 29.9 t, while the necessary average speed reduction (i.e., slow steaming) per sectoral voyage for the requirement compliance is calculated to be in between 4.8%-26%. Slow steaming is assessed to extend the time of voyage for 6.1-10.7 hours on monthly basis and 49-87 hours annually.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48459652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Present paper studies the variation of the blade spindle torque in a controllable pitch propeller (CPP) during the feathering maneuver, which is one of the rare but most challenging propeller maneuvers in CPP operation. The knowledge of the spindle torque under different operating conditions is one of the key features for the CPP controller unit design. The aim of this study is determining the forces needed to be governed to control the blade motion of a CPP converted from a fixed pitch propeller and the scale effect on these forces. So as to obtain a realistic numerical setup, the time-dependent superposed motion of the main rotation of the propeller and the rotation of each blade around its axis is modeled using a hybrid overset/sliding mesh technique. The spindle torque values were calculated during the dynamical variation of the blade pitch in feathering maneuver, and a novel expression is recommended to non-dimensionalize the predicted spindle torque. The result revealed that the required torque values to rotate each blade during the propeller maneuver is rising up to a critical pitch angle. Further increment of the pitch angle results in lower spindle torque values. Furthermore, this critical pitch angle is inversely proportional to the propeller loading.
{"title":"The numerical investigation of spindle torque for a controllable pitch propeller in feathering maneuver","authors":"A. Yurtseven, Kaan Aktay","doi":"10.21278/brod74205","DOIUrl":"https://doi.org/10.21278/brod74205","url":null,"abstract":"Present paper studies the variation of the blade spindle torque in a controllable pitch propeller (CPP) during the feathering maneuver, which is one of the rare but most challenging propeller maneuvers in CPP operation. The knowledge of the spindle torque under different operating conditions is one of the key features for the CPP controller unit design. The aim of this study is determining the forces needed to be governed to control the blade motion of a CPP converted from a fixed pitch propeller and the scale effect on these forces. So as to obtain a realistic numerical setup, the time-dependent superposed motion of the main rotation of the propeller and the rotation of each blade around its axis is modeled using a hybrid overset/sliding mesh technique. The spindle torque values were calculated during the dynamical variation of the blade pitch in feathering maneuver, and a novel expression is recommended to non-dimensionalize the predicted spindle torque. The result revealed that the required torque values to rotate each blade during the propeller maneuver is rising up to a critical pitch angle. Further increment of the pitch angle results in lower spindle torque values. Furthermore, this critical pitch angle is inversely proportional to the propeller loading.","PeriodicalId":55594,"journal":{"name":"Brodogradnja","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49633307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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