The Effect of Cupping on Four-Quadrant Propeller Performance

2009 ◽  
Author(s):  
Jonathan H. Dowsett ◽  
Phillip S. Duerr ◽  
Jacques B. Hadler ◽  
Robin S. Rose
Keyword(s):  
Test Data ◽  
Open Water ◽  
Performance Characteristics ◽  
Hydrodynamic Performance ◽  
Shaft Speed ◽  
Water Efficiency ◽  
Performance Predictions ◽  
Matching Pair ◽  
Four Quadrant ◽  
Propeller Performance

The Webb Hydroflite Propeller Series (WHPS) consists of four matching pairs of three-bladed ten-inch-diameter pleasure craft propellers with P/D ratios varying from 0.6 to 1.2. Recently, one propeller from each matching pair was modified with a uniform trailing edge cup. Cupping is a widely employed and inexpensive aftermarket alternative to repitching a propeller that is not performing in a given application. The hydrodynamic performance characteristics of each modified propeller were determined by open-water and four-quadrant model tests prior to and after cupping. Performance comparisons were made for each pair of propellers tested to determine the level of manufacturing consistency as well as the effects of cupping. Test data for peak open-water efficiency and four-quadrant performance were compared to B-Series propeller data to determine whether the B-Series can be used confidently for performance predictions. It was found that the addition of the cup could be modeled as an increase in effective pitch. For a given KT/J2 operating curve, the cupped propeller operates at a higher advance coefficient than the original propeller when running ahead. The increase in advance coefficient leads to lower shaft speed at a given thrust. When running astern, there is little change in the KT curve for the cupped propeller and therefore negligible change in advance coefficient but there is a large increase in the required torque at a given shaft speed.

Numerical investigation of the rake angle effect on the hydrodynamic performance of propeller in a uniform and nonuniform flow

2019 ◽  
Vol 233 (18) ◽  
pp. 6326-6338
Author(s):  
Hasan Sajedi ◽  
Miralam Mahdi
Keyword(s):  
Open Water ◽  
Rake Angle ◽  
Uniform Flow ◽  
Wake Flow ◽  
Hydrodynamic Performance ◽  
Experimental Result ◽  
Nonuniform Flow ◽  
Solution Scheme ◽  
Propeller Performance ◽  
Thrust And Torque

Marine propeller always operates in the wake of a vehicle (ship, torpedo, submarine) but (due to the high computational cost of simulating vehicle and propeller simultaneously) to investigate the propeller geometric parameters, simulations are usually performed in open-water conditions. In this article, using the computational fluid dynamics method with the control volume approach, the effect of the rake angle on the propeller performance and formation of cavitation in the uniform flow (open water) and the nonuniform flow (wake flow) was investigated. In the nonuniform condition, the array of plates was used to simulate wake at upstream propeller. For uniform flow, steady solution scheme was adopted and for nonuniform flow unsteady solution scheme was adopted, and a moving mesh zone was generated around the propeller. To simulate cavitation a multiphase mixture flow, the Reynolds-averaged Navier–Stokes method was used and modeled by Schnerr Sauer's cavitation model. First, the E779a propeller model for numerical validation in the uniform flow and nonuniform flow was investigated. Numerical results were compared with the experimental result, and there was a good agreement between volume of the cavity, thrust, and torque coefficients. To study the effect of rake angle on the performance of B-series propellers, four models with different rake angles were modeled, and simulation was investigated behind the wake. The results of thrust, torque coefficients, and cavitation volume according to the flow parameters and cavitation number were presented as graphs. The results reveals that in the uniform flow, the rake angle has no significant effect on the propeller performance, but behind the wake flow, increase of rake causes to reduce the force applied to the propeller blades, cavitation volume, and pressure fluctuations on the propeller.

A 2.5D numerical study on open water hydrodynamic performance of a Voith-Schneider propeller

2019 ◽  
Vol 20 (6) ◽  
pp. 617
Author(s):  
Mohammad Bakhtiari ◽  
Hassan Ghassemi
Keyword(s):  
Numerical Method ◽  
Thrust Force ◽  
Numerical Study ◽  
Open Water ◽  
Hydrodynamic Performance ◽  
Maximum Efficiency ◽  
Water Efficiency ◽  
Blade Thickness ◽  
Unsteady Rans ◽  
Marine Vessels

Marine cycloidal propeller (MCP) is a special type of marine propulsors that provides high maneuverability for marine vessels. In a MCP, the propeller axis of rotation is perpendicular to the direction of thrust force. It consists of a number of lifting blade. Each blade rotates about the propeller axis and simultaneously pitches about its own axis. The magnitude and direction of thrust force can be adjusted by controlling the propeller pitch. Voith-Schneider propeller (VSP) is a low-pitch MCP with pure cycloidal blade motion allowing fast, accurate, and stepless control of thrust magnitude and direction. Generally, low-pitch cycloidal propellers are used in applications with low speed maneuvering requirements, such as tugboats, minesweepers, etc. In this study, a 2.5D numerical method based on unsteady RANS equations with SST k-ω turbulent model was implemented to predict the open water hydrodynamic performance of a VSP for different propeller pitches and blade thicknesses. The numerical method was validated against the experimental data before applying to VSP. The results showed that maximum open water efficiency of a VSP is enhanced by increasing the propeller pitch. Furthermore, the effect of blade thickness on open water efficiency is different at various advance coefficients, so that the maximum efficiency produced by the VSP decreases with increasing blade thickness at different propeller pitches.

Numerical Analysis of Hydrodynamic Propeller Performance of LNG Carrier in Open Water

2014 ◽  
Vol 66 (2) ◽  
Author(s):  
M. Nakisa ◽  
A. Maimun ◽  
Yasser M. Ahmed ◽  
Jaswar Jaswar ◽  
A. Priyanto ◽  
...  
Keyword(s):  
Open Water ◽  
Hydrodynamic Performance ◽  
Marine Propeller ◽  
Turbulent Model ◽  
Propeller Blade ◽  
Hydrodynamic Parameters ◽  
Laboratory Facilities ◽  
Mesh Density ◽  
Propeller Performance ◽  
Marine Laboratory

Marine propeller blade geometries, especially LNG carriers, are very complicated and determining the hydrodynamic performance of these propellers using experimental work is very expensive, time consuming and has many difficulties in calibration of marine laboratory facilities. This paper presents the assessment on the effect of turbulent model and mesh density on propeller hydrodynamic parameters. Besides that, this paper focuses on the LNG carrier Tanaga class propeller hydrodynamic performance coefficients such as Kt, Kq and η, with respect to the different advance coefficient (j). Finally, the results from numerical simulation that were calculated based on RANS (Reynolds Averaged Navier Stocks) equations, were compared with existing experimental results, followed by analysis and discussion sections. As a result the maximum hydrodynamic propeller efficiency occurred when j=0.84.

scholarly journals Research on Optimization of Parametric Propeller Based on Anti-Icing Performance and Simulation of Cutting State of Ice Propeller

2021 ◽  
Vol 9 (11) ◽  
pp. 1247
Author(s):  
Yu Lu ◽  
Chunxiao Wu ◽  
Shewen Liu ◽  
Zhuhao Gu ◽  
Wu Shao ◽  
...  
Keyword(s):  
Optimization Design ◽  
International Association ◽  
Equivalent Stress ◽  
Design Procedure ◽  
Optimal Solution ◽  
Open Water ◽  
Hydrodynamic Performance ◽  
Water Efficiency ◽  
Nsga Ii ◽  
Thrust Coefficient

When a ship sails in an ice area, the ice could cause damage to ship hull and the propeller as well as the rudder. In the design process of an ice class propeller, the strength verification of the propeller has always been the focus of the design and research of the ice propeller. Based on the International Association of Classification Societies Unified Requirements for Polar Class (IACS Polar UR), it is required that the maximum torque from the propeller cannot exceed the required value to ensure the safety of the propeller shafting equipment. This paper investigates the hydrodynamic performance of the propeller under the condition of satisfying the propeller’s ice strength. A parametric propeller optimization design procedure was established in which the thrust coefficient and open water efficiency solved by CFD method were selected as the objective function and optimization target, the maximum ice torque was used as the optimization constraint under the condition that the ship’s shafting equipment remains unchanged, the propeller pitch, thickness, and camber at each radial direction were taken as the optimization design variables, and the optimization algorithm of SOBOL and NSGA-II was adopted. The interaction mode of propeller and ice was simulated by the method of explicit dynamics. The equivalent stress and displacement response of the blade during the cutting process of the ice propeller were calculated, monitoring the ice destruction process. The results show that the multi-objective Pareto optimal solution set of thrust coefficient and open water efficiency of the ice class propeller was formed at the design speed while maintain the maximum ice torque not exceeding the original ice torque.

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.

scholarly journals CFD Simulation for Estimating Efficiency of PBCF Installed on a 176K Bulk Carrier under Both POW and Self-Propulsion Conditions

Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1192
Author(s):  
Dong-Hyun Kim ◽  
Jong-Chun Park ◽  
Gyu-Mok Jeon ◽  
Myung-Soo Shin
Keyword(s):  
Cfd Simulation ◽  
Open Water ◽  
Navier Stokes ◽  
Water Efficiency ◽  
Ocean Engineering ◽  
Bulk Carrier ◽  
Incompressible Viscous Flow ◽  
Korea Research Institute ◽  
Torque Coefficient ◽  
Viscous Flow Field

In this paper, the efficiency of Propeller Boss Cap Fins (PBCF) installed at the bulk carrier was estimated under both Propeller Open Water (POW) and self-propulsion conditions. For this estimation, virtual model-basin tests (resistance, POW, and self-propulsion tests) were conducted through Computational Fluid Dynamics (CFDs) simulation. In the resistance test, the total resistance and the wake distribution according to ship speed were investigated. In the POW test, changes of thrust, torque coefficient, and open water efficiency on the propeller according to PBCF installation were investigated. Finally, the International Towing Tank Conference (ITTC) 1978 method was used to predict the effect of PBCF installation on self-propulsive coefficient and brake horsepower. For analyzing incompressible viscous flow field, the Reynolds-Averaged Navier–Stokes (RANS) equation with SST k-ω turbulence model was calculated using Star-CCM+ 11.06.010-R8. All simulation results were validated by comparing the results of model tests conducted at the Korea Research Institute of Ships and Ocean Engineering (KRISO). Consequently, for the self-propulsion test with the PBCF, a 1.5% reduction of brake horsepower was estimated in the simulation and a 0.5% reduction of the brake horsepower was estimated in the experiment.

Experimental Performance of a Trochoidal Propeller with High-Aspect-Ratio Blades

1989 ◽  
Vol 26 (03) ◽  
pp. 192-201 ◽  
Author(s):  
Neil Bose ◽  
Peter S. K. Lai
Keyword(s):  
Aspect Ratio ◽  
High Efficiency ◽  
Open Water ◽  
Finite Amplitude ◽  
Dynamic Stall ◽  
Frictional Drag ◽  
Overall Performance ◽  
Small Ship ◽  
Propeller Performance ◽  
Thrust And Torque

Open-water experiments were done on a model of a cycloidal-type propeller with a trochoidal blade motion. This propeller had three blades with an aspect ratio of 10. These experiments included the measurement of thrust and torque of the propeller over a range of advance ratios. Tests were done for forward and reverse operation, and at zero speed (the bollard pull condition). Results from these tests are presented and compared with: a multiple stream-tube theoretical prediction of the performance of the propeller; and a prediction of the performance of a single blade of the propeller, oscillating in heave and pitch, using unsteady small-amplitude hydrofoil theory with corrections for finite amplitude motion, finite span, and frictional drag. At present, neither of these theories gives a completely accurate prediction of propeller performance over the whole range of advance ratios, but a combination of these approaches, with an allowance for dynamic stall of the blades, should lead to a reliable simple theory for overall performance prediction. Application of a propeller of this type to a small ship is discussed. The aim of the design is to produce a lightly loaded propeller with a high efficiency of propulsion.

Sign in / Sign up

Export Citation Format

Share Document