The grid size of the pod located between the leading c edge of the pod and strut is 10x30 in the axial and tangential directions, respectively. The analysis will reveal that the proper rotor slot number selection has a strong impact on the induction motor performance.
The results of the present numerical method for this podded propulsor in different cases are given in the following sections. It was found a satisfactory agreement with A c experiments and other numerical methods. This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
The vortex strengths are calculated by solving a set of simultaneous equations which satisfy the flow tangency condition at the blade control points. The result of the flow calculation for model scale Reynolds numbers agrees well with that of the experiment of a large cavitation tunnel.
Taegu Lim Thesis Title: Fluid-structure interaction analysis of two-dimensional cross section of yacht sails Year Degree Conferred: On the other hand, a boundary element method BEM is used to solve for the flow around the pod unit axisymmetric pod and strut with and without the presence of the propeller.
The grid size of the A pod along the strut is 25x30 and the rest of the pod grid size is chosen as 10x The singularities that are associated with the blade and wake are known at this point.
While in the earlier numerical method the axial induced velocites by pod and strut parts were included into the calculations on the propeller disc plane, in the present method the tangential induced velocities on the propeller disc plane are included in the calculations as well.
The effect of pod and strut on the propeller and vice versa are discussed. The kinematic boundary condition applied to the body requires the flow to be tangent to the body. Numerical t investigation of propulsive characteristics of podded propeller. In Figure 17, the thrust and torque coefficients KT and KQ and efficiency values of the propeller and the pod unit are shown as compared with those of experiments.
Journal of Fluid Mechanics,Prediction of steady and unsteady marine propeller performance by numerical s lifting-surface theory. Prediction of steady and unsteady marine propeller performance by numerical s lifting-surface theory.
Engineering for the Maritime Environment, c sPart M, The number of panels used along the x direction and tangential direction is 45x30 c r on the pod. The method later was extended to include the cavitating characteristics into the calculations by Lee and a search algorithm for cavity detachment in the case of back and mid-chord cavitation was added by Kinnas et.
Computational Mechanics, 37, The strut is meshed by 25x42 The present numerical method can also be applicable for other types of podded propulsors such as, pusher type or twin c e propeller types with different yaw angles and with different types of fins and winglets.
Daewoo Shipbuilding and Marine Engineering Co. A boundary element method for the analysis of the flow around 3-D cavitating hydrofoils. The possible reasons for the discrepancy c r between experiments and those of present method for the efficiency values may be due to the viscous effects s and the gap effects between hub part and pod part, which are not included into the present calculations.
In this way, the motors have equal rotor resistance and at the same time equal equivalent air gap. AIAA J, 12 2The flow domain around the podded propeller is mainly divided into three parts; the axisymmetric pod part, the strut part and the propeller part. Journal of the Society of Naval Architects of Korea, 39 3pp.
Extensive research is still going as c e increasing on various aspects of podded propulsors. Then, the VLM is re-solved for calculating the propeller hydrodynamic characteristics and induced velocities on control points of pod unit.
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Later, a different puller type of podded propulsor for which the details of geometrical characteristics and experimental results are given in Islam, et. The same equation can also be modified to account for the induced velocities of propeller and induced c e potentials of pod.
The design of a podded propeller base model geometry and prediction of its hydrodynamics. Performance analysis of podded propulsors The main objective of the present work is to further improve the original numerical method developed before for the prediction of performance of podded propellers and to further validate the earlier developed numerical model with a specific emphasis on the hydrodynamic interaction amongst the propulsor components.
A podded propulsor in viscous flow is numerically simulated in this article. The region of fluid is divided into efficient calculation grids. The pressure and viscous force of blades, pod and strut are obtained as functions of an advance coefficient.
The unsteady performance of drag and double reverse propeller podded propulsors in open water was numerically simulated using a computational fluid dynamics (CFD) method.
Prediction of performance of podded propulsors via coupling of a vortex−lattice method with an Euler or a RANS solver. Ocean Engineering Group Report No:The University of Texas at Austin, USA. Numerical methods as well as experimental techniques were described to predict the flow characteristics around different type of podded propulsors, Mishra (), Gupta (), Kinnas (), Bal et al.
() and Ghassemi and Ghadimi (). podded propulsors is combined to estimate the best overall power split between the under- wing and aft-mounted propulsors, assuming that the aircraft is at a steady cruise condition.
The results show that the BLI conﬁguration o ers 6% to 9% reduction in required power at.Analysis of using podded propulsors