scholarly journals Numerical Simulation of Ship Maneuvers through Self-Propulsion

2021 ◽  
Vol 9 (9) ◽  
pp. 1017
Author(s):  
Haodong Shang ◽  
Chengsheng Zhan ◽  
Zuyuan Liu
Keyword(s):  
Evaluation Method ◽  
Body Force ◽  
Cfd Simulation ◽  
Grid Method ◽  
The Body ◽  
Overset Grid ◽  
Force Method ◽  
Body Force Method ◽  
Overset Grid Method ◽  
Experimental Values

The typical maneuvering of a ship can reflect its maneuvering characteristics, which are closely related to the safety and economy of its navigation. The accurate prediction of a ship’s maneuvering characteristics is essential for its preliminary design. This paper adopts the overset grid method to deal with multibody motion and the body-force method to describe the thrust distribution of the propeller at the model scale, as well as to obtain the changes in the hydrodynamic load and the characteristic parameters in a computational fluid dynamics (CFD) maneuver simulation. Then, the paper compares the results with those of a self-propulsion experiment conducted at the China Ship Scientific Research Center. The numerical results show that the maneuverability characteristics obtained from the CFD simulation are in satisfactory agreement with the experimental values, which demonstrates the applicability and reliability of the combination of the overset grid with the body-force method in the numerical prediction of the typical maneuvering of a ship. This provides an effective pre-evaluation method for the prediction of a ship’s maneuvering through self-propulsion.

Assessment Procedure for Multiple Volumetric Flaws in p-M Diagram

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Shinji Konosu
Keyword(s):  
Body Force ◽  
Pressure Vessels ◽  
The Body ◽  
Assessment Procedure ◽  
Force Method ◽  
Reference Stress ◽  
Body Force Method ◽  
Common Problems ◽  
Shielding Effects

Assessment of multiple volumetric flaws is one of the most common problems relating to pressure vessels and piping components. Under the current fitness for service rules, such as ASME, BS, and so on, multiple volumetric flaws are usually recharacterized as an enveloping volumetric flaw (defined as a single larger volumetric flaw) as well as multiple cracklike flaws, following their assessment rules. However, the rules proposed in their codes will not often agree and their justification is unknown. Furthermore, they can provide unrealistic assessment in some cases. In this paper, the interaction between two differently sized nonaligned volumetric flaws such as local thin areas is clarified by applying the body force method. Unlike multiple cracklike flaws, the effect of biaxial stresses on the interaction is evident. Based on the interaction that indicates the magnification and shielding effects and reference stress solutions, a new procedure for multiple volumetric flaws is proposed for assessing the flaws in the p-M (pressure-moment) diagram, which is a simple assessment procedure for vessels with volumetric flaws.

Simplification of the body force method by using the approximated boundaries composed of triangular surfaces.

1988 ◽  
Vol 54 (508) ◽  
pp. 2093-2098
Author(s):  
Hironobu NISITANI ◽  
Hiroshi NOGUCHI ◽  
Dai-heng CHEN ◽  
Hiroaki MINE
Keyword(s):  
Body Force ◽  
The Body ◽  
Force Method ◽  
Body Force Method

Body Force Method for Melan Problem With Hole Using Complex Potentials

2007 ◽  
Author(s):  
B. S. Manjunath ◽  
D. S. Ramakrishna
Keyword(s):  
Stress Analysis ◽  
Body Force ◽  
Infinite Plate ◽  
The Body ◽  
Complex Potentials ◽  
Actual Condition ◽  
Principle Of Superposition ◽  
Concentrated Load ◽  
Force Method ◽  
Body Force Method

The problem of a half plane with concentrated load acting at an interior point is known as melan problem as shown in Fig.1. In the present case melan problem with hole is considered as shown in Fig.2. The body force method is developed for the above case. Body force method is a method based on principle of superposition [1]. In the body force method the actual condition is treated as an imaginary condition i.e. the semi-infinite plate with hole and interior load is treated as a plate without hole; the actual hole is regarded as imaginary on whose periphery boundary forces are applied. The problem is solved by superimposing the stress fields of the boundary forces and concentrated force acting at an arbitrary point to satisfy the prescribed boundary conditions so that the stress condition of the actual plate is approximately equal to that of the imaginary plate [2]. The complex variable method of stress analysis is a versatile technique for stress analysis Problem. The formulas for melan problem are derived and described [3]. Complex potentials are used for stress analysis.

Accurate stress intensity factors for kinked interface crack in bonded dissimilar half-plane

2021 ◽  
pp. 2140030
Author(s):  
Kazuhiro Oda ◽  
Nao-Aki Noda
Keyword(s):  
Stress Intensity ◽  
Interface Crack ◽  
Present Method ◽  
Body Force ◽  
The Body ◽  
Intensity Factors ◽  
Force Method ◽  
Kinked Crack ◽  
Body Force Method ◽  
Crack Tips

In this study, the stress intensity factor (SIF) of an interface kinked crack is analyzed by the singular integral equation of the body force method. The problem can be expressed by distributing the body force doublets of the tension and shear types along all the boundaries of the kinked and interface crack parts. The SIFs can be obtained directly from the densities of the body force doublets at the crack tips. Although the problem has already been calculated using the crack connection model, the accuracy of the analysis has not been clarified. From the analysis results in this study, it can be seen that the SIFs calculated by the crack connection model have a nonnegligible error, and the present method gives more accurate results. The advantage of the present method is that the SIFs of the kinked and the interface crack tips can be obtained at the same time with high accuracy.

Sign in / Sign up

Export Citation Format

Share Document