Boundary Element Method Applied to Added Mass Coefficient Calculation of the Skewed Marine Propellers

AbstractThe paper mainly aims to study computation of added mass coefficients for marine propellers. A three-dimensional boundary element method (BEM) is developed to predict the propeller added mass and moment of inertia coefficients. Actually, only few experimental data sets are available as the validation reference. Here the method is validated with experimental measurements of the B-series marine propeller. The behavior of the added mass coefficients predicted based on variation of geometric and flow parameters of the propeller is calculated and analyzed. BEM is more accurate in obtaining added mass coefficients than other fast numerical methods. All added mass coefficients are nondimensionalized by fluid density, propeller diameter, and rotational velocity. The obtained results reveal that the diameter, expanded area ratio, and thickness have dominant influence on the increase of the added mass coefficients.

Download Full-text

The Added Mass Coefficient computation of sphere, ellipsoid and marine propellers using Boundary Element Method

Polish Maritime Research ◽

10.2478/v10012-011-0003-1 ◽

2011 ◽

Vol 18 (1) ◽

pp. 17-26 ◽

Cited By ~ 18

Author(s):

Hassan Ghassemi ◽

Ehsan Yari

Keyword(s):

Boundary Element Method ◽

Numerical Methods ◽

Boundary Element ◽

Mass Matrix ◽

Added Mass ◽

Experimental Results ◽

Marine Propellers ◽

Mass Coefficient ◽

Added Mass Coefficient ◽

Element Method

The Added Mass Coefficient computation of sphere, ellipsoid and marine propellers using Boundary Element Method Added mass is an important and effective dynamic coefficient in accelerating, non uniform motion as a result of fluid accelerating around a body. It plays an important role, especially in vessel roll motion, control parameters as well as in analyzing the local and global vibration of a vessel and its parts like propellers and rudders. In this article, calculating the Added Mass Coefficient has been examined for a sphere, ellipsoid, marine propeller and hydrofoil; using numerical Boundary Element Method. Since an Ellipsoid and a sphere have simple geometric shapes and the Analytical values of their added mass coefficients are available, so that the results of added mass matrix are obtained and evaluated, using the boundary element method. Then the added mass matrix is computed in a given geometrical and flow specifications for a specific propeller and its results are studied versus experimental results, which it's current numerical data In comparison with other numerical methods has a good conformity with experimental results. The most important advantage of the method in determining the added mass matrix coefficients for the surface and underwater vessels and the marine propellers is extracting all the added mass coefficients with very good Accuracy, while in other numerical methods it is impossible to extract all the coefficients with the Desired Accuracy.

Download Full-text