Towards a New Mathematical Model for Investigating Course Stability and Maneuvering Motions of Sailing Yachts

2016 ◽  
Author(s):  
Manolis Angelou ◽  
Kostas J. Spyrou
Keyword(s):  
Mathematical Model ◽  
Aerodynamic Force ◽  
Wave Forces ◽  
Element Formulation ◽  
Wave Excitation ◽  
Structure Interaction ◽  
Stage Of Development ◽  
Course Stability ◽  
Shell Finite Element ◽  
Interaction Problem

In order to create capability for analyzing course instabilities of sailing yachts in waves, the authors are at an advanced stage of development of a mathematical model comprised of two major components: an aerodynamic, focused on the calculation of the forces on the sails, taking into account the variation of their shape under wind flow; and a hydrodynamic one, handling the motion of the hull with its appendages in water. Regarding the first part, sails provide the aerodynamic force necessary for propulsion. But being very thin, they have their shape adapted according to the locally developing pressures. Thus, the flying shape of a sail in real sailing conditions differs from its design shape and it is basically unknown. The authors have tackled the fluid-structure interaction problem of the sails using a 3d approach where the aerodynamic component of the model involves the application of the steady form of the Lifting Surface Theory, in order to obtain the force and moment coefficients, while the deformed shape of each sail is obtained using a relatively simple Shell Finite Element formulation. The hydrodynamic part consists of modeling hull reaction, hydrostatic and wave forces. A Potential Flow Boundary Element Method is used to calculate the Side Forces and Added Mass of the hull and its appendages. The Side Forces are then incorporated into an approximation method to calculate Hull Reaction terms. The calculation of resistance is performed using a formulation available in the literature. The wave excitation is limited to the calculation of Froude - Krylov forces.

scholarly journals Large-Amplitude Sloshing With Submerged Blocks

1990 ◽  
Vol 112 (1) ◽  
pp. 104-108 ◽  
Author(s):  
A. Huerta ◽  
W. K. Liu
Keyword(s):  
Experimental Data ◽  
Free Surface ◽  
Nonlinear Behavior ◽  
Forced Vibrations ◽  
Element Formulation ◽  
Arbitrary Lagrangian Eulerian ◽  
Water Pool ◽  
Surface Motion ◽  
Structure Interaction ◽  
Interaction Problem

The computer simulation of forced vibrations induced on a water pool is presented in this paper. The complexity of the seismic fluid-structure interaction problem is accentuated by the large free surface motion. To overcome this difficulty, the arbitrary Lagrangian Eulerian (ALE) finite element formulation is employed. Moreover, the nonlinear behavior of the free surface motion is also taken into account. The results of the numerical simulation are compared with published experimental data and the effectiveness of the ALE algorithm is demonstrated.

scholarly journals ROBUST HIGH ORDER NON-CONFORMING FINITE ELEMENT FORMULATION FOR TIME DOMAIN FLUID-STRUCTURE INTERACTION

2005 ◽  
Vol 13 (03) ◽  
pp. 403-431 ◽  
Author(s):  
JULIEN DIAZ ◽  
PATRICK JOLY
Keyword(s):  
Time Domain ◽  
Fluid Structure Interaction ◽  
High Order ◽  
Three Dimensions ◽  
Element Formulation ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Conforming Finite Element ◽  
Interaction Problem ◽  
Variational Formulations

In this paper we present various numerical methods for solving time-dependent fluid-structure interaction problem in two or three dimensions that we claim to be efficient, robust and highly accurate. These methods, based on mixed variational formulations, are explicit and conservative and can be of arbitrary high order in space. Their accuracy will be illustrated via a comparison with analytical solutions in simple configuration.

TO THE STABILITY OF TANK VEHICLES IN THE BRAKE MODE

2019 ◽  
pp. 27-32
Author(s):  
Denys Popelysh ◽  
Yurii Seluk ◽  
Sergyi Tomchuk
Keyword(s):  
Mathematical Model ◽  
Control Systems ◽  
Distribution Systems ◽  
Traffic Accidents ◽  
Road Traffic ◽  
Center Of Mass ◽  
Dynamic Processes ◽  
Course Stability ◽  
The Stability ◽  
Tank Vehicles

This article discusses the question of the possibility of improving the roll stability of partially filled tank vehicles while braking. We consider the dangers associated with partially filled tank vehicles. We give examples of the severe consequences of road traffic accidents that have occurred with tank vehicles carrying dangerous goods. We conducted an analysis of the dynamic processes of fluid flow in the tank and their influence on the basic parameters of the stability of vehicle. When transporting a partially filled tank due to the comparability of the mass of the empty tank with the mass of the fluid being transported, the dynamic qualities of the vehicle change so that they differ significantly from the dynamic characteristics of other vehicles. Due to large displacements of the center of mass of cargo in the tank there are additional loads that act vehicle and significantly reduce the course stability and the drivability. We consider the dynamics of liquid sloshing in moving containers, and give examples of building a mechanical model of an oscillating fluid in a tank and a mathematical model of a vehicle with a tank. We also considered the method of improving the vehicle’s stability, which is based on the prediction of the moment of action and the nature of the dynamic processes of liquid cargo and the implementation of preventive actions by executive mechanisms. Modern automated control systems (anti-lock brake system, anti-slip control systems, stabilization systems, braking forces distribution systems, floor level systems, etc.) use a certain list of elements for collecting necessary parameters and actuators for their work. This gives the ability to influence the course stability properties without interfering with the design of the vehicle only by making changes to the software of these systems. Keywords: tank vehicle, roll stability, mathematical model, vehicle control systems.

scholarly journals Investigation of a Stochastic Inverse Method to Estimate an External Force: Applications to a Wave-Structure Interaction

2012 ◽  
Vol 2012 ◽  
pp. 1-25 ◽  
Author(s):  
S. L. Han ◽  
Takeshi Kinoshita
Keyword(s):  
External Force ◽  
Inverse Method ◽  
Inverse Function ◽  
Wave Structure ◽  
Dynamic Responses ◽  
Structure Interaction ◽  
External Forces ◽  
Interaction Problem ◽  
Wave Structure Interaction

The determination of an external force is a very important task for the purpose of control, monitoring, and analysis of damages on structural system. This paper studies a stochastic inverse method that can be used for determining external forces acting on a nonlinear vibrating system. For the purpose of estimation, a stochastic inverse function is formulated to link an unknown external force to an observable quantity. The external force is then estimated from measurements of dynamic responses through the formulated stochastic inverse model. The applicability of the proposed method was verified with numerical examples and laboratory tests concerning the wave-structure interaction problem. The results showed that the proposed method is reliable to estimate the external force acting on a nonlinear system.

Analysis of Acoustic-Structure Interaction Using a High-Order Doubly Asymptotic Approximation

2016 ◽  
Vol 24 (01) ◽  
pp. 1550021 ◽  
Author(s):  
Heekyu Woo ◽  
Young S. Shin
Keyword(s):  
Order Approximation ◽  
Stable Model ◽  
Approximation Model ◽  
Third Order ◽  
Acoustic Structure ◽  
Structure Interaction ◽  
Proposed Model ◽  
The Stability ◽  
Third Order Approximation ◽  
Interaction Problem

In this paper, a new third-order approximation model for an acoustic-structure interaction problem is introduced. The new approximation model is designed to be an accurate and a stable model for predicting the response of a submerged structure. The proposed model is obtained by combining two lower order approximation models instead of using an operator matching method. The stability of this model is checked by a modal analysis. Finally, the approximation model is coupled to the spherical shell structure, and its performance is checked by a shock analysis.

An implicit full Eulerian method for the fluid-structure interaction problem

2010 ◽  
Vol 65 (1-3) ◽  
pp. 150-165 ◽  
Author(s):  
S. Ii ◽  
K. Sugiyama ◽  
S. Takeuchi ◽  
S. Takagi ◽  
Y. Matsumoto
Keyword(s):  
Fluid Structure Interaction ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Eulerian Method ◽  
Interaction Problem

scholarly journals Space/time multigrid for a fluid–structure-interaction problem

2008 ◽  
Vol 58 (12) ◽  
pp. 1951-1971 ◽  
Author(s):  
E.H. van Brummelen ◽  
K.G. van der Zee ◽  
R. de Borst
Keyword(s):  
Fluid Structure Interaction ◽  
Space Time ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Interaction Problem
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