Calculation of the Harmonic Structure of Marine Propellers Torque and Thrust

1994 ◽  
Author(s):  
Dinu Taraza ◽  
Nicolae Buzbuchi ◽  
Jean Sever Popovici
Keyword(s):  
Harmonic Structure ◽  
Marine Propellers

RBFN Based Efficiency Optimization Method of Induction Motor Utilized in Electrically Driven Marine Propellers

2011 ◽  
Vol 131 (1) ◽  
pp. 68-75
Author(s):  
Supari ◽  
Syafaruddin ◽  
I Made Yulistya Negara ◽  
Mochamad Ashari ◽  
Takashi Hiyama
Keyword(s):  
Induction Motor ◽  
Optimization Method ◽  
Efficiency Optimization ◽  
Marine Propellers

scholarly journals Coupled Engine-Propeller Selection Procedure to Minimize Fuel Consumption at a Specified Speed

2021 ◽  
Vol 9 (1) ◽  
pp. 59
Author(s):  
Mina Tadros ◽  
Roberto Vettor ◽  
Manuel Ventura ◽  
Carlos Guedes Soares
Keyword(s):  
Fuel Consumption ◽  
Selection Procedure ◽  
Optimization Procedure ◽  
Operating Point ◽  
Power Prediction ◽  
Ship Routing ◽  
Marine Propellers ◽  
Operational Profile ◽  
Calm Water ◽  
Engine Operating Point

This study presents a practical optimization procedure that couples the NavCad power prediction tool and a nonlinear optimizer integrated into the Matlab environment. This developed model aims at selecting a propeller at the engine operating point with minimum fuel consumption for different ship speeds in calm water condition. The procedure takes into account both the efficiency of the propeller and the specific fuel consumption of the engine. It is focused on reducing fuel consumption for the expected operational profile of the ship, contributing to energy efficiency in a complementary way as ship routing does. This model assists the ship and propeller designers in selecting the main parameters of the geometry, the operating point of a fixed-pitch propeller from Wageningen B-series and to define the gearbox ratio by minimizing the fuel consumption of a container ship, rather than only maximizing the propeller efficiency. Optimized results of the performance of several marine propellers with different number of blades working at different cruising speeds are also presented for comparison, while verifying the strength, cavitation and noise issues for each simulated case.

A new start for marine propellers?

2004 ◽  
Vol 48 (11) ◽  
pp. 34-38 ◽  
Author(s):  
George Marsh
Keyword(s):  
Marine Propellers

noiseNet: A neural network to predict marine propellers’ underwater radiated noise

2021 ◽  
Vol 236 ◽  
pp. 109542
Author(s):  
Youjiang Wang ◽  
Keqi Wang ◽  
Moustafa Abdel-Maksoud
Keyword(s):  
Neural Network ◽  
Radiated Noise ◽  
Marine Propellers ◽  
Underwater Radiated Noise

Marine Propellers

1986 ◽  
Vol 18 (1) ◽  
pp. 367-403 ◽  
Author(s):  
J E Kerwin
Keyword(s):  
Marine Propellers

Influence of Marine Propeller Geometry on Turbulence Model Selection for CFD Simulations

2021 ◽  
Vol 55 (2) ◽  
pp. 150-164
Author(s):  
Mohamed R. Shouman ◽  
Mohamed M. Helal
Keyword(s):  
Turbulent Flows ◽  
Small Diameter ◽  
Turbulence Models ◽  
Dynamics Simulation ◽  
Geometrical Parameters ◽  
Test Case ◽  
Transition Model ◽  
Transient Flows ◽  
Marine Propellers ◽  
Numerical Predictions

Abstract One of the big challenges yet to be addressed in the numerical simulation of wetted flow over marine propellers is the influence of propellers' geometry on the selection of turbulence models. Since the Reynolds number is a function of the geometrical parameters of the blades, the flow type is controlled by these parameters. The majority of previous studies employed turbulence models that are only appropriate for fully turbulent flows, and consequently, they mostly caused high discrepancy between numerical predictions and corresponding experimental measurements specifically at geometrical parameters generating laminar and transient flows. The present article proposes a complete procedure of computational fluid dynamics simulation for wetted flows over marine propellers using ANSYS FLUENT 16 and employing both transition-sensitive and fully turbulent models for comparison. The K-Kl-ω transition model and the fully turbulent standard K-ε model are suggested for this purpose. The investigation is carried out for two different propellers in geometrical features: the INSEAN E779a model and the Potsdam Propeller Test Case (PPTC) model. The results demonstrate the effectiveness of the K-Kl-ω transition model for the INSEAN E779a propeller rather than the PPTC propeller. This can be interpreted as the narrow-bladed and small-diameter propellers have more likely laminar and transient flows over its blades.

Application of a Boundary Element Method in the Prediction of Unsteady Blade Sheet and Developed Tip Vortex Cavitation on Marine Propellers

2004 ◽  
Vol 48 (01) ◽  
pp. 15-30
Author(s):  
Hanseong Lee ◽  
Spyros A. Kinnas
Keyword(s):  
Boundary Element Method ◽  
Boundary Element ◽  
Pressure Fluctuations ◽  
Ship Hull ◽  
Tip Vortex ◽  
Tip Vortex Cavitation ◽  
Marine Propellers ◽  
Sheet Cavitation ◽  
Numerical Predictions ◽  
Element Method

Most marine propellers operate in nonaxisymmetric inflows, and thus their blades are often subject to an unsteady flow field. In recent years, due to increasing demands for faster and larger displacement ships, the presence of blade sheet and tip vortex cavitation has become very common. Developed tip vortex cavitation, which often appears together with blade sheet cavitation, is known to be one of the main sources of propeller-induced pressure fluctuations on the ship hull. The prediction of developed tip vortex cavity as well as blade sheet cavity is thus quite important in the assessment of the propeller performance and the corresponding pressure fluctuations on the ship hull. A boundary element method is employed to model the fully unsteady blade sheet (partial or supercavitating) and developed tip vortex cavitation on propeller blades. The extent and size of the cavity is determined by satisfying both the dynamic and the kinematic boundary conditions on the cavity surface. The numerical behavior of the method is investigated for a two-dimensional tip vortex cavity, a three-dimensional hydrofoil, and a marine propeller subjected to nonaxisymmetric inflow. Comparisons of numerical predictions with experimental measurements are presented.

Beyond bandlimited sampling of speech spectral envelope imposed by the harmonic structure of voiced sounds

2013 ◽  
Author(s):  
Hideki Kawahara ◽  
Masanori Morise ◽  
Tomoki Toda ◽  
Ryuichi Nisimura ◽  
Toshio Irino
Keyword(s):  
Spectral Envelope ◽  
Harmonic Structure
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