Scan Science and Technology
Contact Leading Edge Experts & Companies
Advance Coefficient
The Experts below are selected from a list of 240 Experts worldwide ranked by ideXlab platform
Neil Bose – 1st expert on this subject based on the ideXlab platform
-
Performance of a family of surface piercing propellers
Royal Institution of Naval Architects Transactions, 2020Co-Authors: M Fernando, Neil Bose, A Scamardella, Brian VeitchAbstract:Tests on a systematic series of surface piercing propellers were analyzed to study some aspects of scaling the performance of this kind of
propulsor. In particular, the influence of the Weber number, depth of immersion, and shaft rake are discussed and results for variations in
these conditions are presented. Regression equations are given of the relationship between critical Advance Coefficient and Weber number,
and of the thrust and torque Coefficients at Advance Coefficients above the critical values. This work is the result of co-operative research on
the scaling of the performance of surface piercing propellers that was jointly undertaken by the University of Genoa, University of Naples,
Memorial University of Newfoundland, and the Institute for Marine Dynamics, NRC. -
Preliminary blade load measurements on a model propeller in ice
, 2020Co-Authors: Corwyn Moores, Brian Veitch, Neil Bose, Stephen J. Jones, J. I. Bell, John CarltonAbstract:Preliminary results of a series of model scale propeller
experiments are presented. A large (0270mm) model of a
highly skewed controllable pitch propeller was tested in both
open water and ice covered water in the ice tank at the Institute
for Marine Dynamics. Both the open water and ice experiments
were done at four different pitch settings, each over a range of
Advance Coefficient. The ice strength and the depth cut into the
ice by the propeller were varied in the ice tests. The main aims
of the experiments were to measure the effects of these
variables on blade loads, in addition to their effects on shaft
loads. Shaft loads were measured using conventional
dynamometry. Loads on one blade were measured using a hubmounted
blade dynamometer designed and built for these tests.
The blade dynamometer is described and some preliminary
shaft and blade load measurements are presented and discussed. -
Numerical investigation of propulsive characteristics of podded propellers
, 2020Co-Authors: Islam, R Taylor, J Quinton, Brian Veitch, Neil Bose, Bruce ColbourneAbstract:Numerical investigations were performed to predict effects of propeller hub taper angle and pod geometry configurations on propulsive performance. An existing time domain panel method code was extended to handle the simulation tasks. The effect of taper angle was examined in terms of shaft thrust Coefficient, KT, and torque Coefficient, KQ, for different taper angles of -15° (pull/tractor configuration) and +15° (push configuration). The predicted pressure distribution was also analyzed to investigate the effect of taper ratio on pressure Coefficient, Cp, at the blade root section. The effects of pod-strut geometry on KT and KQ of a propeller with taper angles of 15° and 20° with two pods both in push configuration were examined. A complementary experimental study of the effects of taper angle on propulsive performance was also conducted for 15° and 20° taper angles in push configuration. Numerical predictions and experimental measurement showed a good agreement over a wide range of Advance Coefficients from the bollard pull condition to the design Advance Coefficient of about 1.0.
Brian Veitch – 2nd expert on this subject based on the ideXlab platform
-
Preliminary blade load measurements on a model propeller in ice
, 2020Co-Authors: Corwyn Moores, Brian Veitch, Neil Bose, Stephen J. Jones, J. I. Bell, John CarltonAbstract:Preliminary results of a series of model scale propeller
experiments are presented. A large (0270mm) model of a
highly skewed controllable pitch propeller was tested in both
open water and ice covered water in the ice tank at the Institute
for Marine Dynamics. Both the open water and ice experiments
were done at four different pitch settings, each over a range of
Advance Coefficient. The ice strength and the depth cut into the
ice by the propeller were varied in the ice tests. The main aims
of the experiments were to measure the effects of these
variables on blade loads, in addition to their effects on shaft
loads. Shaft loads were measured using conventional
dynamometry. Loads on one blade were measured using a hubmounted
blade dynamometer designed and built for these tests.
The blade dynamometer is described and some preliminary
shaft and blade load measurements are presented and discussed. -
Performance of a family of surface piercing propellers
Royal Institution of Naval Architects Transactions, 2020Co-Authors: M Fernando, Neil Bose, A Scamardella, Brian VeitchAbstract:Tests on a systematic series of surface piercing propellers were analyzed to study some aspects of scaling the performance of this kind of
propulsor. In particular, the influence of the Weber number, depth of immersion, and shaft rake are discussed and results for variations in
these conditions are presented. Regression equations are given of the relationship between critical Advance Coefficient and Weber number,
and of the thrust and torque Coefficients at Advance Coefficients above the critical values. This work is the result of co-operative research on
the scaling of the performance of surface piercing propellers that was jointly undertaken by the University of Genoa, University of Naples,
Memorial University of Newfoundland, and the Institute for Marine Dynamics, NRC. -
Performance of dynamic azimuthing podded propulsor
International shipbuilding progress, 2020Co-Authors: Ayhan Akinturk, Mohammed Islam, Brian VeitchAbstract:This paper presents results and analyses of an experimental study into the effects of static and dynamic azimuthing conditions on the propulsive characteristics of a puller podded unit in open water. The model propulsor was instrumented to measure thrust and torque of the propeller, three orthogonal forces and moments on the unit, rotational speed of the propeller, azimuthing angle and azimuthing rate. The model was first tested over a range of Advance Coefficients at various static azimuthing angles in the range of-180° to 180°. These tests were followed by tests in which the azimuthing angle was varied dynamically at certain azimuthing rate and propeller rotational speed. A comparative study of the performance Coefficients at static and dynamic azimuthing conditions in the range of-180° to 180° is presented. The performance Coefficients of the propeller and the pod unit showed a strong dependence on the propeller loading and azimuthing angle. The Coefficients in static azimuthing conditions fit well with a 10th order polynomial fit of the data obtained in the dynamic azimuthing condition in the corresponding azimuthing angles and Advance Coefficient. An uncertainty analysis of the measurements is also presented. © 2012-IOS Press and the authors.
Hassan Ghassemi – 3rd expert on this subject based on the ideXlab platform
-
Hydrodynamic Characteristic of the Marine Propeller in the Oblique Flow with Various Current Angle by CFD Solver
, 2018Co-Authors: Alireza Abbasi, Hassan Ghassemi, Manouchehr FadavieAbstract:The purpose of this study is to obtain the hydrodynamic characteristic of propeller in the oblique flow with various current angle (means oblique flow). The Reynolds-averaged Navier-Stokes (RANS) equations solver of the StarCCM+ software is employed with a realizable k-e turbulent model. In the current study, the B-Series propeller (B:4-70) is used because of its use in commercial vessels. The simulation is conducted in two parts: at first, examination of propeller behavior in direct flow conditions and comparison with experimental conditions and in the next step analysis of the propeller in the oblique flow with angles of 10, 20, 30 and 40 degrees. The results are shown that the thrust and torque Coefficients (KTx and KQx) are reduced by increasing the angle of flow and increasing the Advance Coefficient.
-
Numerical analysis of surface piercing propeller in unsteady conditions and cupped effect on ventilation pattern of blade cross-section
Journal of Marine Science and Technology, 2016Co-Authors: Ehsan Yari, Hassan GhassemiAbstract:The aim of this study is to calculate hydrodynamic performance and ventilation flow around wedge, 2D blade and 3D surface piercing propeller (SPP), using computational fluid dynamic based on Reynolds-averaged Navier–Stokes method. First, numerical analyses for two-phase fluid flow around the wedge and 2D blade section (cupped and non-cupped) are presented. Flow ventilation, pressure distribution and forces are determined and compared with experimental data. Then, the method is extended to predict the hydrodynamic performance of propeller SPP-841B. The propeller exhibits a cupped blade. In the simulated configuration, SPP is one-third submerged ( I = h/D = 0.33 ) and is working at various loadings with full ventilation occurring at low Advance Coefficient ( J ). The open water performance, pressure distribution, forces/moments and ventilation pattern on the SPP-841B model are obtained and compared with experimental data. The numerical results are in good agreement with experimental measurements, especially at high Advance Coefficient.
-
Numerical simulation of turbulent flow around podded propeller in azimuthing conditions
Proceedings of the International Conference on Offshore Mechanics and Arctic Engineering – OMAE, 2012Co-Authors: Reza Shamsi, Hassan GhassemiAbstract: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. Copyright © 2012 by ASME.