BACKSTEPPING CONTROL OF NONLINEAR ROLL MOTION FOR A TRAWLER WITH FIN STABILIZER

2021 ◽  
Vol 159 (A2) ◽  
Author(s):  
H Demirel ◽  
A Doğrul ◽  
S Sezen ◽  
F Alarçin
Keyword(s):  
Lift Coefficient ◽  
Design Procedure ◽  
Nonlinear Damping ◽  
Backstepping Control ◽  
Roll Motion ◽  
Scaled Model ◽  
3 Dimensional ◽  
Roll Control ◽  
Fin Stabilizer ◽  
Volume Method

A backstepping control design procedure for nonlinear fin roll control of a trawler is presented in this paper. A roll equation consisting of linear and nonlinear damping and restoring moment on the roll response is expressed. Flow analyses are carried out for a scaled model of trawler type fishing vessel including fin stabilizers on both sides of the hull. The fin stabilizer geometry is chosen as NACA 0015 foil section which is widely used in the literature. The flow analyses are performed by using a commercial computational fluid dynamics (CFD) software based on finite volume method. The flow problem is modeled in a 3-dimensional manner while the flow is considered as steady, incompressible and fully turbulent. The numerical model consists of the ship wetted surface and the fin stabilizer in order to investigate the hull-fin interaction. Non-dimensional lift coefficients of the fin stabilizer for different angles of attack are gained. Both controlled and uncontrolled roll motions are examined and simulated in time domain for the maximum lift coefficient. Backstepping controller for roll motion has given a rapid and precise result.

Backstepping Control of Nonlinear Roll Motion for a Trawler with Fin Stabilizer

2017 ◽  
Vol Vol 159 (A2) ◽  
Author(s):  
H Demirel ◽  
A Doğrul ◽  
S Sezen ◽  
F Alarçin
Keyword(s):  
Lift Coefficient ◽  
Design Procedure ◽  
Nonlinear Damping ◽  
Backstepping Control ◽  
Roll Motion ◽  
Scaled Model ◽  
3 Dimensional ◽  
Roll Control ◽  
Fin Stabilizer ◽  
Volume Method

A backstepping control design procedure for nonlinear fin roll control of a trawler is presented in this paper. A roll equation consisting of linear and nonlinear damping and restoring moment on the roll response is expressed. Flow analyses are carried out for a scaled model of trawler type fishing vessel including fin stabilizers on both sides of the hull. The fin stabilizer geometry is chosen as NACA 0015 foil section which is widely used in the literature. The flow analyses are performed by using a commercial computational fluid dynamics (CFD) software based on finite volume method. The flow problem is modeled in a 3-dimensional manner while the flow is considered as steady, incompressible and fully turbulent. The numerical model consists of the ship wetted surface and the fin stabilizer in order to investigate the hull-fin interaction. Non dimensional lift coefficients of the fin stabilizer for different angles of attack are gained. Both controlled and uncontrolled roll motions are examined and simulated in time domain for the maximum lift coefficient. Backstepping controller for roll motion has given a rapid and precise result.

An Extended Linearized Inverse Theory for Fully Cavitating Hydrofoil Section Design

1979 ◽  
Vol 23 (04) ◽  
pp. 260-271
Author(s):  
Blaine R. Parkin ◽  
Joe Fernandez
Keyword(s):  
Design Theory ◽  
Parametric Design ◽  
Lift Coefficient ◽  
Design Procedure ◽  
Cavitation Number ◽  
Inverse Theory ◽  
Cavity Surface ◽  
Moment Coefficient ◽  
Section Design ◽  
Cavity Thickness

A new design theory for fully cavitating hydrofoils is based upon a linearized inverse theory of two-dimensional cavity flows at arbitrary cavitation number. The cavity surfaces are assumed to originate at the leading and trailing edges of the wetted surface. This paper reviews and completes the basic theory, which leads to a parametric design technique. In the resulting design procedure, one specifies the design lift coefficient, the cavitation number and the upper cavity thickness at two points along the profile chord. A prescribed pressure distribution shape is also selected. These quantities determine the profilelesgn, which consists of the upper cavity and wetted surface contours, the design angle of attack, the cavity length, the drag coefficient, the moment coefficient and the lift-to-drag ratio. The chief new feature of the third design procedure is that the designer can now prescribe two points on the cavity surface instead of one as heretofore. Although the designer must observe certain constraints when he specifies these two values of cavity thickness, the new procedure is still found to be more general and more flexible than design procedures studied previously.

Effects of Nonlinear Damping Washers on the Automatic Ball Balancer for Optical Disk Drives

2005 ◽  
Author(s):  
Cheng-Kuo Sung ◽  
Paul C. P. Chao ◽  
Ben-Cheng Yo
Keyword(s):  
Nonlinear Dynamics ◽  
Steady State ◽  
Multiple Scales ◽  
Method Of Multiple Scales ◽  
Dynamic Performance ◽  
Nonlinear Damping ◽  
Disk Drives ◽  
Optical Disc ◽  
Scaled Model ◽  
Jump Phenomena

This study is devoted to explore the effect of nonlinear dynamics of damping washers on the dynamic performance of automatic ball balancer (ABB) system installed in optical disc drives. The ABB is generally used on rotational system to reduce vibration. Researches have been conducted to study the performance of the ABB by investigating the nonlinear dynamics of the system; however, the model adopted often consider the damping washer in a typical ABB suspension system as a linear one, which does not reflect the fact that the practical washers are inevitably exhibit nontrivial nonlinear dynamics at some range of operation, deviating the ABB performance away from the expecteds. In this study, a complete dynamic model of the ABB including a detailed nonlinear model of the damping washers based on experimental data for practical wahers is established. The method of multiple scales is then applied to formulate a scaled model to find all possible steady-state ball positions and analyze stabilities. It is found that with reasonable level of nonlinearity, the balancing balls of the ABB are still reside at the desired positions at steady state, rendering expected vibration reduction; however, jump phenomena also occurs as the spindle operated through natural frequency of the suspension, causing unwanted system vibrations. Numerical simulations and experiments are conducted to verify the theoretical findings. The obtained results are used to predict the level of residual vibration, with which the guidelines on choices of the nonlinear damping washers are distilled to achieve desired performance.

Dimensional Study for Brazilian FPSO

2005 ◽  
Author(s):  
Daniel Cueva ◽  
Marcos Donato ◽  
Fernando Torres ◽  
Felipe Campos ◽  
Jose A. Ferrari ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Environmental Conditions ◽  
Weather Conditions ◽  
Roll Motion ◽  
Scaled Model ◽  
Campos Basin ◽  
Real Behavior ◽  
Wind Characteristics ◽  
Different Shapes ◽  
Cooperative Project

After the boom of converted floating, production, storage and offloading systems, based on the old VLCC design, many engineering institutes started thinking about optimum dimension for new units. However, these new FPSOs designs carried out worldwide concerns about good seakeeping behavior when considering general weather conditions, in order to apply their project to different locations around the globe. Analyzing the Brazilian specific conditions, it was verified that, considering waves, current and wind characteristics, the dimension proportions found in the projected units were not the best options, mostly because of the swell waves influence. Thus, in a cooperative project between University of Sao Paulo and PETROBRAS, the best dimensions for a specific case were studied, based on real premises from Campos Basin. During the study, the roll motion, which usually creates operational limits during hard environmental conditions, was focused. It was possible not only to evaluate the best breath and draught relations, but also the inclusion of a structured skirt in the ship bilge. The influence of different shapes in the ship’s bow and stern were also evaluated, showing interesting results regarding the forces applied on the vessel. All the analyses were conducted considering numerical analysis, and the final dimensions were applied to a scaled model, which allowed to verify the real behavior of the projected unit in a test basin. As a conclusion, it was possible to define an optimized hull for the PETROBRAS premises, giving them a real design to be used in future explorations.

Robust BackStepping Control Based DRNN for Flight Simulator

2010 ◽  
Vol 139-141 ◽  
pp. 1708-1713 ◽  
Author(s):  
Dong Kai Shen ◽  
Jing Jing Wang ◽  
Zheng Hua Liu
Keyword(s):  
High Performance ◽  
Design Procedure ◽  
Backstepping Control ◽  
Flight Simulator ◽  
System Control ◽  
Control Performance ◽  
External Disturbances ◽  
Motion Simulator ◽  
Backstepping Controller ◽  
Simulation Results

Flight motion simulator is one kind of servo system with uncertainties and nonlinearities. To acquire higher frequency response and good robustness for the flight simulator, we present a Backstepping controller based on a Diagonal Recurrent Neural Network (DRNN) to work out this problem. For one thing, the design procedure of the robust Backstepping controller is described. Subsequently, the principle and the design steps of DRNN are analyzed and expatiated respectively. In the end, simulation results on the flight motion simulator show that robust backstepping control based on DRNN can compensate for external disturbances and enhance robustness of the system control performance. Therefore both robustness and high performance of the flight motion simulator are achieved.

Design of Reservoir Recognition Technique Component - Open Porosity in Non-Polarizing Electrodes

2017 ◽  
Vol 890 ◽  
pp. 308-311
Author(s):  
Jakub Skibinski ◽  
Tomasz Wejrzanowski ◽  
Krzysztof Jan Kurzydlowski
Keyword(s):  
Porous Materials ◽  
Pore Size ◽  
Open Porosity ◽  
Complex Geometry ◽  
Size Variation ◽  
Design Procedure ◽  
Ceramic Materials ◽  
Geometrical Features ◽  
Materials Used ◽  
Volume Method

In the present study modeling of permeability of open-porosity ceramic materials used in non-polarizing electrodes is addressed. The structure of the material filling the electrode determines the infiltration of the ceramic structure by electrolyte, which influences the efficiency of the electrodes. The composition of electrode material was characterized with Scanning Electron Microscope Hitachi S3500N with EDS detector and the structure was determined with use of XRadia XCT400 tomograph . The complex geometry of porous materials has been designed using procedure based on Laguerre-Voronoi tessellations (LVT). A set of porous structures with different geometrical features has been developed using LVT algorithm. The approach used here allows to investigate the influence of geometrical features such pore size variation on the permeability of studied materials. Pressure drop characteristics of the developed structures has been analyzed using finite volume method (FVM). The results show that permeability of porous materials is strongly related with distribution of pore size. The study exhibits the utility of developed design procedure for optimization of non-polarizing electrodes performance.

Hydrodynamic Trends from a Generalized Design Procedure for Fully Cavitating Hydrofoil Sections

1979 ◽  
Vol 23 (04) ◽  
pp. 272-283
Author(s):  
Blaine R. Parkin ◽  
Joe Fernandez
Keyword(s):  
Parametric Design ◽  
Lift Coefficient ◽  
Design Procedure ◽  
Feasibility Studies ◽  
Cavitation Number ◽  
Hydrodynamic Performance ◽  
Cavity Surface ◽  
Cavity Flows ◽  
Moment Coefficient ◽  
Cavity Thickness

An extended design procedure for fully cavitating hydrofoils is based upon a linearized inverse theory of two-dimensional cavity flows at arbitrary cavitation number. The cavity surfaces are assumed to originate at the leading and trailing edges of the wetted surface. This paper completes the basic theory and gives detailed examples obtained from the resulting parametric design technique. In this procedure, one specifies the design lift coefficient, the cavitation number and the upper cavity thickness at two points along the profile chord. A prescribed pressure distribution shape is also selected. These quantities determine the profile design, which consists of the upper cavity and wetted surface contours, the design angle of attack, the cavity length, the drag coefficient, the moment coefficient and the lift-to-drag ratio. The method also includes off-design calculations in accordance with the direct theory of cavity flows, which determines the flow states for which interference can occur between the upper surface of the cavity and the upper nonwetted surface of the profile. The hydrodynamic performance of specific "point designs" is also given by these direct calculations. The chief new feature of the generalized design procedure is that it gives a designer the ability to prescribe two points on the cavity surface instead of one as heretofore. Although certain constraints must be observed by the designer when specifying these two values of cavity thickness, the third procedure is found to be more general and more flexible than design procedures studied previously. The necessary constraints are incorporated in the computer logic for the method. The fact that linearized theory is used tends to limit the applicability of the method to conceptual design and feasibility studies. The computer program for the procedure has been found to be economical and well suited for its intended purpose.

The Numerical Study for the Thermal Characteristics of 3D Vertical Stacked Die Packages

2009 ◽  
Author(s):  
Chih-Kuang Yu ◽  
Ming-Che Hsieh ◽  
Chun-Kai Liu ◽  
Ming-Ji Dai ◽  
Ra-Min Tain
Keyword(s):  
Numerical Study ◽  
Thermal Characteristics ◽  
Junction Temperature ◽  
Geometrical Parameters ◽  
Heat Transfer Mechanism ◽  
3 Dimensional ◽  
Material Parameters ◽  
Silicon Vias ◽  
Thermal Simulations ◽  
Volume Method

In this study, the thermal simulations of 3 dimensional IC packages base on 4-layer vertical stacked die (bare die on bare die) with TSV (through silicon vias) and micro-bumps structure are conducted. The thermal models by finite volume method are developed for different geometrical parameters (TSV, micro-bumps distribution arrangement and spacer thickness) and material property (thermal conductivity of spacer). The thermal performance and the heat transfer mechanism for the stacked die package are analyzed for optimizing the geometrical and material parameters. Not only the temperature distributions but also the junction temperature and thermal resistances in 4-layer stacked die package with different multi-die power configurations are shown and discussed.

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