scholarly journals State equations in the mathematical model of dynamic behaviour of multihull floating unit

2010 ◽  
Vol 17 (1) ◽  
pp. 33-38
Author(s):  
Agnieszka Królicka
Keyword(s):  
Mathematical Model ◽  
Dynamic Analysis ◽  
Dynamic Behaviour ◽  
Physical Models ◽  
Head Wave ◽  
Sea Waves ◽  
State Equations ◽  
Initial Stage ◽  
Mutual Relations ◽  
The Mathematical Model

State equations in the mathematical model of dynamic behaviour of multihull floating unit This paper concerns dynamic behaviour of multihull floating unit of catamaran type exposed to excitations due to irregular sea waves. Dynamic analysis of multihull floating unit necessitates, in its initial stage, to determine physical model of the unit and next to assume an identified mathematical model. Correctly elaborated physical models should contain information on the basis of which a mathematical model could be built. Mathematical models describe mutual relations between crucial quantities which characterize a given system in time domain. The dynamic analysis of multihull unit was performed under assumption that the unit's model has been linear and exposed to action of irregular sea waves. Mathematical model of such dynamic system is represented by state equations. The formulated equations take into account encounter of head wave which generates symmetrical motions of the unit, i.e. surge, heave and pitch. For solving the equations the following three wave spectra were taken into consideration: - ISSC (International Ship Structures Congress) spectrum - Pierson-Moskowitz spectrum - Paszkiewicz spectrum.

Dynamic Analysis on a Cable-Driven Interventional Active Catheter Using Kane's Method Combined with Screw Theory

2014 ◽  
Vol 527 ◽  
pp. 140-145
Author(s):  
Da Xu Zhao ◽  
Bai Chen ◽  
Guo Zhong Shou ◽  
Yu Qi Gu
Keyword(s):  
Mathematical Model ◽  
Dynamic Analysis ◽  
Motion Control ◽  
Screw Theory ◽  
Driving Forces ◽  
Structure Design ◽  
Kinematics And Dynamics ◽  
Existing Problems ◽  
Blind Area ◽  
The Mathematical Model

In view of the existing problems of traditional interventional catheters, particularly poor activity, operation difficulty and mass blind area, a novel interventional catheter with a cable-driven active head-end is proposed, and a prototype was built to verify the performance. This paper deals with the kinematics and dynamics of the cable-driven prototype, a dynamic model based on Kanes method combined with screw theory was presented in this paper. According the mathematical model and the prototypes structure, the analysis of kinematics and dynamics of active head-end-end is done in the environment of Mathematica. The needed driving forces of every joint when the system moving along planned trajectory are calculated. The results can provide a basis for the structure design and motion control of the interventional active catheter.

Dynamic Analysis for the Design of CALM System in Shallow and Deep Waters

1997 ◽  
Vol 119 (3) ◽  
pp. 151-157 ◽  
Author(s):  
Y.-L. Hwang
Keyword(s):  
Mathematical Model ◽  
Dynamic Analysis ◽  
Model Test ◽  
Time Domain ◽  
Time Domain Analysis ◽  
Mooring Lines ◽  
Deep Waters ◽  
Wave Drift ◽  
The Mathematical Model ◽  
Survival Condition

This paper presents a time domain analysis approach to evaluate the dynamic behavior of the catenary anchor leg mooring (CALM) system under the maximum operational condition when a tanker is moored to the terminal, and in the survival condition when the terminal is not occupied by a tanker. An analytical model, integrating tanker, hawser, buoy, and mooring lines, is developed to dynamically predict the extreme mooring loads and buoy orbital motions, when responding to the effect of wind, current, wave frequency, and wave drift response. Numerical results describing the dynamic behaviors of the CALM system in both shallow and deepwater situations are presented and discussed. The importance of the line dynamics and hawser coupled buoy-tanker dynamics is demonstrated by comparing the present dynamic analysis with catenary calculation approach. Results of the analysis are compared with model test data to validate the mathematical model presented.

The static and dynamic characteristics of a pressure relief valve with a proportional solenoid-controlled pilot stage

2002 ◽  
Vol 216 (2) ◽  
pp. 143-156 ◽  
Author(s):  
R Maiti ◽  
R Saha ◽  
J Watton
Keyword(s):  
Mathematical Model ◽  
Dynamic Characteristics ◽  
Dynamic Behaviour ◽  
Practical Experience ◽  
Pressure Relief Valve ◽  
Relief Valve ◽  
Pressure Relief ◽  
Static And Dynamic Characteristics ◽  
Good Comparison ◽  
The Mathematical Model

The steady state and dynamic characteristics of a two-stage pressure relief valve with proportional solenoid control of the pilot stage is studied theoretically as well as experimentally. The mathematical model is studied within the MATLAB-SIMULINK environment and the non-linearities have been considered via the use of appropriate SIMULINK blocks. The detailed modelling has resulted in a good comparison between simulation and measurement, albeit assumptions had to be made regarding the solenoid dynamic characteristic based upon practical experience. The use of this characteristic combined with additional dynamic terms not previously considered allows new estimations of internal characteristics to be made such as the damping flowrate. The overall dynamic behaviour has been shown to be dominated by the solenoid characteristic relating force to applied voltage.

Studying Dynamic Behaviour of Flexible Rotors With an Analytic Model That Includes Non-Linear Supports, Non-Stiff Support Structure and Torsion Flexibility

2007 ◽  
Author(s):  
Heller G. Sa´nchez A. ◽  
Jesu´s M. Pintor B.
Keyword(s):  
Mathematical Model ◽  
Dynamic Analysis ◽  
Dynamic Behaviour ◽  
Mathematical Formulation ◽  
Model Parameters ◽  
Analytic Model ◽  
Support Structure ◽  
Stationary Response ◽  
Rigid Structure ◽  
Flexible Rotors

This article presents a mathematical formulation based on FEM for the dynamic analysis of flexible rotors that are not grounded necessary to a rigid structure. Furthermore, it uses the component synthesis in order to introduce the behavior of the structure where the rotor is grounded. The developed mathematical model calculates the model parameters stationary response.

Computations of Three-Dimensional Gas-Turbine Combustion Chamber Flows

1979 ◽  
Vol 101 (3) ◽  
pp. 326-336 ◽  
Author(s):  
M. A. Serag-Eldin ◽  
D. B. Spalding
Keyword(s):  
Mathematical Model ◽  
Turbulent Flows ◽  
Combustion Process ◽  
Three Dimensional ◽  
Solution Algorithm ◽  
Physical Models ◽  
Turbulence Energy ◽  
Experimental Conditions ◽  
Diffusion Controlled ◽  
The Mathematical Model

The paper presents a mathematical model for three-dimensional, swirling, recirculating, turbulent flows inside can combustors. The present model is restricted to single-phase, diffusion-controlled combustion, with negligible radiation heat-transfer; however, the introduction of other available physical models can remove these restrictions. The mathematical model comprises differential equations for: continuity, momentum, stagnation enthalpy, concentration, turbulence energy, its dissipation rate, and the mean square of concentration fluctuations. The simultaneous solution of these equations by means of a finite-difference solution algorithm yields the values of the variables at all internal grid nodes. The prediction procedure, composed of the mathematical model and its solution algorithm, is applied to predict the fields of variables within a representative can combustor; the results are compared with corresponding measurements. The predicted results give the same trends as the measured ones, but the quantitative agreement is not always acceptable; this is attributed to the combustion process not being truly diffusion-controlled for the experimental conditions investigated.

Accommodating Thickness in Origami-Based Deployable Arrays1

2013 ◽  
Vol 135 (11) ◽  
Author(s):  
Shannon A. Zirbel ◽  
Robert J. Lang ◽  
Mark W. Thomson ◽  
Deborah A. Sigel ◽  
Phillip E. Walkemeyer ◽  
...  
Keyword(s):  
Mathematical Model ◽  
High Ratio ◽  
Physical Models ◽  
Solar Array ◽  
Outer Diameter ◽  
Space Applications ◽  
The Creation ◽  
The Mathematical Model

The purpose of this work is to develop approaches to accommodate thickness in origami-based deployable arrays with a high ratio of deployed-to-stowed diameter. The origami flasher model serves as a basis for demonstrating the approach. A thickness-accommodating mathematical model is developed to describe the flasher. Practical modifications are presented for the creation of physical models and two options are proposed: allowing the panels to fold along their diagonals or applying a membrane backing with specified widths at fold-lines. The mathematical model and hardware modifications are employed to create several physical models. The results are general and apply to a range of applications. An example is provided by the application that motivated the work: a deployable solar array for space applications. The model is demonstrated in hardware as a 1/20th scale prototype with a ratio of deployed-to-stowed diameter of 9.2 (or 1.25 m deployed outer diameter to 0.136 m stowed outer diameter).

scholarly journals MODELLING THE DYNAMIC BEHAVIOUR OF THE TRUCK-CRANE

Transport ◽  
2012 ◽  
Vol 26 (4) ◽  
pp. 410-417 ◽  
Author(s):  
Radomir Mijailović
Keyword(s):  
Mathematical Model ◽  
Dynamic Analysis ◽  
Dynamic Behaviour ◽  
Generalized Coordinates ◽  
Mechanical Models

The paper deals with the problem of a dynamic analysis of truck-cranes. Therefore, the article has developed a mechanical-mathematical model having 18 generalized coordinates. Depending on the type of truck crane operation as well as on the fact whether the aim of the article is to conduct the dynamic analysis of the whole truck crane or only that of one of its components, simpler mechanical models are also offered. The presented model is more realistic than those describing the dynamic behaviour of the truck-crane performing all necessary functions, i.e. a mobile means of lifting, transportation and reloading.

High Cycle Fatigue Cracks at Radial Fan Impellers Caused by Aeroelastic Self-Excited Impeller Vibrations: Part 2 — Mechanism and Mathematical Model

1999 ◽  
Author(s):  
Alexander Ni
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
High Cycle Fatigue ◽  
Dynamic Behaviour ◽  
Fatigue Cracks ◽  
Model Fit ◽  
Acoustic Properties ◽  
Cycle Fatigue ◽  
Pressure Oscillations ◽  
The Mathematical Model

Abstract The radial impeller of the main fan of hydrogen cooled generator has been noted to sustain fatigue failure. Experimental data pointed out to the impeller selfexcitation as the cause of the failure. According to the mechanism and the mathematical model suggested in the paper the impeller selfexcitation is due to the feedback between the natural impeller vibrations and the acoustic field in the side room adjacent to the impeller. The impeller vibrations induce the pressure oscillations in the side room that in turn influence the impeller. Under special conditions of the fan dynamic behaviour and the acoustic properties of the fan side room this feedback leads to the selfexcitation. The suggested mechanism and the model fit all the experimental data. Their validity has been also later confirmed by the maintaince experience of other similar machines.

Numerical simulation of the spherically symmetric tumor growth in the lymph node

2010 ◽  
Vol 7 ◽  
pp. 143-152
Author(s):  
V.N. Kireev ◽  
O.A. Solnyshkina
Keyword(s):  
Mathematical Model ◽  
Lymph Node ◽  
Tumor Growth ◽  
Growth Parameters ◽  
Symmetric Case ◽  
Spherically Symmetric ◽  
Intercellular Interaction ◽  
Initial Stage ◽  
Multiphase Systems ◽  
The Mathematical Model

Within the framework of the multiphase systems mechanics we consider the mathematical model of the initial stage of the tumor growth in a lymph node consisting of two kinds of cells. Adhesive intercellular interaction and distribution of nutrients (oxygen) are taken into account. For a spherically symmetric case, the distribution of tumor growth parameters was numerically obtained and some features of its development at the initial stage were defined.

Dynamic Analysis and Optimization of Pivot Points of Telescopic Jib Based on Genetic Algorithm

2014 ◽  
Vol 721 ◽  
pp. 87-90
Author(s):  
Tao Liu ◽  
Wei Hui Wang ◽  
Ren Wu Yuan ◽  
Fei Lu
Keyword(s):  
Genetic Algorithm ◽  
Mathematical Model ◽  
Dynamic Analysis ◽  
Prototype Model ◽  
Work Process ◽  
Force Condition ◽  
Lifting Force ◽  
Adams Software ◽  
Optimized Conditions ◽  
The Mathematical Model

Using ADAMS software to create a virtual prototype model of luffing mechanism of QY20A crane truck. The entire work process of telescopic arm is analyzed, and the result shows that luffing cylinder lifting force is maximum at the beginning moment. The luffing cylinder force is calculated in different conditions based on the analysis and select the maximum force condition as optimized conditions, make the mathematical model of optimization and optimized using genetic algorithm, which played a guiding role for the of telescopic boom design.

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