Recent Developments in Computational Methods for the Analysis of Ducted Propellers in Open Water

2019 ◽  
Vol 63 (4) ◽  
pp. 219-234
Author(s):  
João Baltazar ◽  
José A. C. Falcão de Campos ◽  
Johan Bosschers ◽  
Douwe Rijpkema
Keyword(s):  
Computational Methods ◽  
Open Water ◽  
Boundary Element Methods ◽  
Navier Stokes ◽  
Hydrodynamic Analysis ◽  
Numerical Predictions ◽  
Ducted Propeller ◽  
Recent Developments ◽  
Propeller Performance ◽  
Ducted Propellers

This article presents an overview of the recent developments at Instituto Superior Técnico and Maritime Research Institute Netherlands in applying computational methods for the hydrodynamic analysis of ducted propellers. The developments focus on the propeller performance prediction in open water conditions using boundary element methods and Reynolds-averaged Navier-Stokes solvers. The article starts with an estimation of the numerical errors involved in both methods. Then, the different viscous mechanisms involved in the ducted propeller flow are discussed and numerical procedures for the potential flow solution proposed. Finally, the numerical predictions are compared with experimental measurements.

Numerical analysis of ducted propeller performance under open water test condition

2013 ◽  
Vol 18 (3) ◽  
pp. 381-394 ◽  
Author(s):  
Long Yu ◽  
Martin Greve ◽  
Markus Druckenbrod ◽  
Moustafa Abdel-Maksoud
Keyword(s):  
Numerical Analysis ◽  
Open Water ◽  
Ducted Propeller ◽  
Water Test ◽  
Propeller Performance

scholarly journals Calculations of the Hydrodynamic Characteristics of a Ducted Propeller Operating in Oblique Flow

2017 ◽  
Vol 10 (20) ◽  
pp. 31
Author(s):  
Hassan Ghassemi ◽  
Sohrab Majdfar ◽  
Hamid Forouzan
Keyword(s):  
Stokes Equations ◽  
Open Water ◽  
Hydrodynamic Performance ◽  
Numerical Code ◽  
Navier Stokes ◽  
Hydrodynamic Characteristics ◽  
Navier Stokes Equations ◽  
Oblique Flow ◽  
Ducted Propeller ◽  
Acceptable Agreement

The purpose of this paper is to calculate the hydrodynamic performance of a ducted propeller (hereafter Duct_P) at oblique flows. e numerical code based on the solution of the Reynolds-averaged Navier– Stokes equations (RANSE) applies to the Kaplan propeller with 19A duct. e shear-stress transport (SST)-k-ω turbulence model is used for the present results. Open-water hydrodynamic results are compared with experimental data showing a relatively acceptable agreement. Two oblique flow angles selected to analyze in this paper are 10 and 20 degrees. Numerical results of the pressure distribution and hydrodynamic performance are presented and discussed. 

scholarly journals Prediction of the Propeller Performance at Different Reynolds Number Regimes with RANS

2021 ◽  
Vol 9 (10) ◽  
pp. 1115
Author(s):  
João Baltazar ◽  
Douwe Rijpkema ◽  
José Falcão de Campos
Keyword(s):  
Reynolds Number ◽  
Turbulence Model ◽  
Scale Effects ◽  
Open Water ◽  
Reynolds Numbers ◽  
Navier Stokes ◽  
Transition Model ◽  
Sst Turbulence Model ◽  
Propeller Performance ◽  
Selection Of

In this study, a Reynolds averaged Navier-Stokes solver is used for prediction of the propeller performance in open-water conditions at different Reynolds numbers ranging from 104 to 107. The k−ω SST turbulence model and the γ−R˜eθt correlation-based transition model are utilised and results compared for a conventional marine propeller. First, the selection of the turbulence inlet quantities for different flow regimes is discussed. Then, an analysis of the iterative and discretisation errors is made. This work is followed by an investigation of the predicted propeller flow at variable Reynolds numbers. Finally, the propeller scale-effects and the influence of the turbulence and transition models on the performance prediction are discussed. The variation of the flow regime showed an increase in thrust and decrease in torque for increasing Reynolds number. From the comparison between the turbulence model and the transition model, different flow solutions are obtained for the Reynolds numbers between 105 and 106, affecting the scale-effects prediction.

scholarly journals Cavitation Prediction of Ship Propeller Based on Temperature and Fluid Properties of Water

2020 ◽  
Vol 8 (6) ◽  
pp. 465
Author(s):  
Muhammad Yusvika ◽  
Aditya Rio Prabowo ◽  
Dominicus Danardono Dwi Prija Tjahjana ◽  
Jung Min Sohn
Keyword(s):  
Physical Properties ◽  
Stokes Equations ◽  
Open Water ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Numerical Predictions ◽  
Fluid Properties ◽  
Turbulent Closure ◽  
Influence Of Temperature On ◽  
Lower Temperature

Cavitation is a complex phenomenon to measure, depending on site conditions in specific regions of the Earth, where there is water with various physical properties. The development of ship and propulsion technology is currently intended to further explore territorial waters that are difficult to explore. Climate differences affect the temperature and physical properties of water on Earth. This study aimed to determine the effect of cavitation related to the physical properties of water. Numerical predictions of a cavitating propeller in open water and uniform inflow are presented with computational fluid dynamics (CFD). Simulations were carried out using Ansys. Numerical simulation based on Reynolds-averaged Navier–Stokes equations for the conservative form and the Rayleigh–Plesset equation for the mass transfer cavitation model was conducted with turbulent closure of the fully turbulent K-epsilon (k-ε) model and shear stress transport (SST). The influence of temperature on cavitation extension was investigated between 0   and   50   ° C . The results obtained showed a trend of cavitation occurring more aggressively at higher water temperature than at lower temperature.

scholarly journals Numerical Simulation of the Ducted Propeller and Application to a Semi-Submerged Vehicle

2020 ◽  
Vol 27 (2) ◽  
pp. 19-29
Author(s):  
Jin Zou ◽  
Guoge Tan ◽  
Hanbing Sun ◽  
Jie Xu ◽  
Yongkang Hou
Keyword(s):  
Numerical Simulation ◽  
Numerical Simulations ◽  
Open Water ◽  
The Self ◽  
Hydrodynamic Performance ◽  
Navier Stokes ◽  
Cfd Simulations ◽  
Ducted Propeller ◽  
Numerical Software ◽  
Numerical Approaches

AbstractThe self-propulsion test of underwater vehicles is the key technique for predicting and evaluating the navigation performance of these submersibles. In this study, the numerical simulation of a standard propeller JD7704+Ka4-70 is first presented and the results are compared with experiments to validate the numerical approaches. The reason why the propulsion efficiency of the ducted propeller is higher than that of the conventional propeller is explored. Then, the paper proposes a series of numerical simulations conducted to test the performance of the ducted propeller designed according to the JD7704+Ka4-70 in order to match with the unmanned semi-submerged vehicle (USSV), and the propeller’s open water characteristic curves are obtained. The results show a reasonable agreement with the regression analysis. Afterwards, the numerical simulations focus on a self-propulsion test of the USSV with the designed ducted propeller and the self-propulsion point is obtained. The streamlines through the hull as well as the ducted propellers are clearly obtained, together with the velocity distributions of the propeller plane. The results vividly demonstrate the hydrodynamic performance of the USSV with the designed propellers. In this paper, all the CFD simulations are based on the numerical software, Star-CCM+, and use the Reynolds-averaged Navier‒Stokes (RANS) equations with the shear stress transport (SST) k-omega turbulence model.

Numerical Simulation of Turbulent Flow Around Podded Propeller in Azimuthing Conditions

2012 ◽  
Author(s):  
Reza Shamsi ◽  
Hassan Ghassemi
Keyword(s):  
Turbulent Flow ◽  
Open Water ◽  
Navier Stokes ◽  
Hydrodynamic Characteristics ◽  
Characteristic Parameters ◽  
Hydrodynamic Analysis ◽  
Podded Propulsor ◽  
Performance Curves ◽  
Yaw Angle ◽  
Thrust And Torque

This paper investigates the numerical modeling of turbulent flow and hydrodynamic analysis of podded propeller in open water and azimuthing conditions. The RANS (Reynolds-Averaged Navier Stokes) based solver is used in order to study the variations of hydrodynamic characteristics of podded propeller at various angles. The variations of thrust and torque coefficients as functions of the advance coefficient are obtained at various yaw angles. Turbulent flow around the propeller and pod are presented. At first, the propeller is analyzed in open water condition in absence of pod and strut. Next flow around pod and strut are simulated without effect of propellers. Finally, the whole unit is studied in zero yaw angle and azimuthing condition. These investigations are performed for two podded propulsor configurations: puller and pusher. Total forces on the unit in each direction and propeller torque are computed for a range of advance coefficients from 0.2 to 1. Yaw angle of pod are modified from +15° to −15° by increments of 5°. Computational results are examined against with available experimental data. Characteristic parameters including torque and thrust of propeller, axial force, and side force of unit are presented as functions of advance coefficient and yaw angle. The performance curves of the propeller obtained by numerical method are compared and verified by the experimental results. The results show that the propeller thrust, torque, and podded unit forces and moments in azimuthing condition depend on propeller advance coefficient and yaw angle.

scholarly journals A Comparative Study of Computational Methods for Wave-Induced Motions and Loads

2021 ◽  
Vol 9 (1) ◽  
pp. 83 ◽  
Author(s):  
Jens Ley ◽  
Ould el Moctar
Keyword(s):  
Numerical Methods ◽  
Comparative Study ◽  
Computational Methods ◽  
Boundary Element Methods ◽  
Navier Stokes ◽  
Strip Theory ◽  
Time Histories ◽  
Structural Failures ◽  
Response Amplitude Operators ◽  
Wave Induced

Ship hull structural damages are often caused by extreme wave-induced loads. Reliable load predictions are required to minimize the risk of structural failures. One conceivable approach relies on direct computations of extreme events with appropriate numerical methods. In this perspective, we present a systematic study comparing results obtained with different computational methods for wave-induced loads and motions of different ship types in regular and random irregular long-crested extremes waves. Significant wave heights between 10.5 and 12.5 m were analyzed. The numerical methods differ in complexity and are based on strip theory, boundary element methods (BEM) and unsteady Reynolds-Averaged Navier–Stokes (URANS) equations. In advance to the comparative study, the codes applied have been enhanced by different researchers to account for relevant nonlinearities related to wave excitations and corresponding ship responses in extreme waves. The sea states investigated were identified based on the Coefficient of Contribution (CoC) method. Computed time histories, response amplitude operators and short-term statistics of ship responses and wave elevation were systematically compared against experimental data. While the results of the numerical methods, based on potential theory, in small and moderate waves agreed favorably with the experiments, they deviated considerably from the measurements in higher waves. The URANS-based predictions compared fairly well to experimental measurements with the drawback of significantly higher computation times.

Steady cavitating propeller performance by using OpenFOAM, StarCCM+and a boundary element method

2016 ◽  
Vol 231 (2) ◽  
pp. 411-440 ◽  
Author(s):  
Stefano Gaggero ◽  
Diego Villa
Keyword(s):  
Boundary Element Method ◽  
Open Source ◽  
Boundary Element ◽  
Open Water ◽  
Fundamental Aspect ◽  
Test Case ◽  
Numerical Predictions ◽  
Propeller Performance ◽  
Thrust And Torque ◽  
Element Method

Accurate and reliable numerical predictions of propeller performance are a fundamental aspect for any analysis and design of a modern propeller. Prediction of cavitation and of cavity extension is another important task, since cavitation is one of the crucial aspects that influences efficiency in addition to propagated noise and blade vibration and erosion. The validation of the numerical tools that support the design process, including open-source codes, is, consequently, essential. The public availability of measurements and observations which cover not only usual thrust and torque in open water conditions (including cavitation) but also unsteady functioning with pressure pulse measurements in the case of the Potsdam Propeller Test Case certainly represents an extremely useful source of information and an excellent chance for verification and validation purposes. In the present work, the prediction of the Potsdam Propeller Test Case propeller performance using the OpenFOAM computational fluid dynamics package is proposed. After a preliminary validation and calibration of the OpenFOAM native Schnerr–Sauer interphase mass transfer model for cavitating flow, based on the experimental results on a 2D NACA66Mod hydrofoil, open water propeller performance and cavitation predictions are carried out. The OpenFOAM results are finally compared both with the available experimental measurements and with calculations carried out with StarCCM+ and with a proprietary boundary element method code, in order to assess the accuracy and the overall capabilities of the open-source tools (from meshing to post-processing) available in the OpenFOAM package. The comparison, in addition to assessing the accuracy of the open-source approach, is aimed to verify its advantages and drawbacks with respect to widely used solvers and to further verify the reliability of traditional boundary element method approaches that are still widely adopted for design and optimization (thanks to their extremely higher computational efficiency) in a very demanding test case.

scholarly journals Investigation on the Performance of a Ducted Propeller in Oblique Flow

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Qin Zhang ◽  
Rajeev K. Jaiman ◽  
Peifeng Ma ◽  
Jing Liu
Keyword(s):  
Open Water ◽  
Flow Dynamics ◽  
Navier Stokes ◽  
System A ◽  
Oblique Flow ◽  
Ducted Propeller ◽  
Blade Tip ◽  
Propeller Blades ◽  
Les Model ◽  
Thrust And Torque

In this study, the ducted propeller has been numerically investigated under oblique flow, which is crucial and challenging for the design and safe operation of the thruster driven vessel and dynamic positioning (DP) system. A Reynolds-averaged Navier–Stokes (RANS) model has been first evaluated in the quasi-steady investigation on a single ducted propeller operating in open water condition, and then a hybrid RANS/LES model is adapted for the transient sliding mesh computations. A representative test geometry considered here is a marine model thruster, which is discretized with structured hexahedral cells, and the gap between the blade tip and nozzle is carefully meshed to capture the flow dynamics. The computational results are assessed by a systematic grid convergence study and compared with the available experimental data. As a part of the novel contribution, multiple incidence angles from 15 deg to 60 deg have been analyzed with different advance coefficients. The main emphasis has been placed on the hydrodynamic loads that act on the propeller blades and nozzle as well as their variation with different configurations. The results reveal that while the nozzle absorbs much effort from the oblique flow, the imbalance between blades at different positions is still noticeable. Such unbalance flow dynamics on the blades, and the nozzle has a direct implication on the variation of thrust and torque of a marine thruster.

Prediction of Performance of Tip Loaded Propeller and its Induced Pressures on the Hull

2020 ◽  
Author(s):  
Seungnam Kim ◽  
Spyros A. Kinnas
Keyword(s):  
Open Water ◽  
Tip Vortex ◽  
Navier Stokes ◽  
Paper Briefly ◽  
Water Characteristics ◽  
Cavitation Performance ◽  
Numerical Predictions ◽  
Unsteady Wake ◽  
Wake Alignment ◽  
Initial Knowledge

Abstract In this paper, a boundary element method (BEM) is applied to a tip loaded propeller (TLP) to predict its open water characteristics and induced hull pressures under fully-wetted and uniform inflow. Tip of a TLP blade has a winglet-like tip plate on the pressure side to improve the overall propeller efficiency over the traditional open tip propellers by preventing circulation loss toward the tip region. TLPs are also used to reduce the tip vortex strength and thus free from the trade off the propeller efficiency against the cavitation performance; therefore, predicting their performance early in the designing stage via numerical applications can provide the initial knowledge on the loading distributions and cavitation performance. In the present method, the trailing wake is first aligned using the full wake alignment (FWA) scheme by aligning the wake surface to the local stream in order to satisfy the force free condition. The FWA is shown to improve the open water characteristics of the TLPs compared to the simplified alignment scheme that ignores the details of the flow behind the trailing edge due to the simplicity of the method. Afterwards, a pressure-BEM solver is used to solve for the diffraction potentials on the hull and estimate the propeller-induced hull pressures. In this case, both the FWA and the unsteady wake alignment scheme (UWA), which considers the time dependency of the problem, produce the same results as the testing flow is assumed to be uniform. This paper briefly introduces the model TLP, proper ways to consider the viscous effect on the blade surface, wake alignment scheme, and the pressure-BEM solver. Then, the predicted open water characteristics of the benchmark TLP and its induced hull pressures are compared to the experimental data, as well as the results from unsteady full-blown Reynolds-Averaged Navier-Stokes simulations for validations of the numerical predictions.

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