Modeling the Maneuvering Behavior of Container Carriers in Shallow Water

2007 ◽  
Vol 51 (04) ◽  
pp. 287-296 ◽  
Author(s):  
G. Delefortrie ◽  
M. Vantorre
Keyword(s):  
Mathematical Model ◽  
Shallow Water ◽  
Independent Set ◽  
Model Tests ◽  
Forward Speed ◽  
Ship Maneuvering ◽  
Model Based ◽  
Captive Model Tests ◽  
Water Effects ◽  
The Mathematical Model

Due to the expansion of the dimensions of container vessels, the available maneuvering space in harbor areas and their access channels is decreasing as waterway authorities are often unable to increase the channel dimensions at the same pace. The under keel clearance is an especially important parameter for ship maneuver-ability and controllability. After an overview of the shallow water effects on ship maneuvering, a new mathematical maneuvering model based on captive model tests is introduced. The mathematical model is valid in a large under keel clearance range and is applicable in four quadrants of forward speed: propeller rate combinations, drift angles, and yaw angles. The mathematical model has been validated by means of an independent set of captive model tests.

Analysis of the Mathematical Model of the Spray Dose Applied by the Field Sprayer Nozzles

2016 ◽  
Vol 20 (2) ◽  
pp. 71-79
Author(s):  
Karol Garbiak ◽  
Jan Jurga
Keyword(s):  
Mathematical Model ◽  
Angular Velocity ◽  
Forward Speed ◽  
Spray Application ◽  
Suggested Model ◽  
Independent Variables ◽  
Model Based ◽  
The Mathematical Model

AbstractThe article presents analysis of the mathematical model for determination of a momentary dose of spray applied by the field sprayer nozzles which move on the curve with the forward speed the value of which may differ from the speed accepted for regulation. Regulation speed and regulation dose, real forward speed of a sprayer, angular velocity during the curve movement, and the coefficient of the nozzle location towards the axis of the sprayer turn are independent variables in the suggested model. Based on the mathematical model, plots were drawn and analyses of relation of the spray dose to particular variables were carried out including inter alia, a repeated field spray, application of a dose which considerably differs from the regulation dose and diversity of the dose on the working width of the sprayer.

Captive Model Tests for Assessing Maneuverability of a Damaged Surface Combatant with Initial Heel Angle

2020 ◽  
Vol 64 (04) ◽  
pp. 392-406
Author(s):  
Jeonghwa Seo ◽  
Dae Hyuk Kim ◽  
Jeongsoo Ha ◽  
Shin Hyung Rhee ◽  
Hyeon Kyu Yoon ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Model Tests ◽  
Naval Research ◽  
Test Model ◽  
Scaled Model ◽  
Model Based ◽  
Office Of Naval Research ◽  
Captive Model Tests ◽  
Ship Maneuverability ◽  
Damaged Ship

The present study is about the application of a four-degree-of-freedom (4DOF) maneuvering mathematical model based on Abkowitz’s model for assessing damaged ship maneuverability with initial asymmetry. A scaled model of the Office of Naval Research Tumblehome hull with a damaged compartment was used as the test model. Based on the survivability regulations for naval vessels, the damaged compartment was designed and located near the bow, such that it had an initial heel and trim. Static and dynamic captive model tests were performed on the damaged ship model to determine the maneuvering coefficients for the maneuvering mathematical model. Maneuvering simulations were carried out with the captive model test data and 4DOF maneuvering mathematical model. The advance speed in the maneuver reduced more in the damaged condition than in the intact condition, and maneuverability was severely degraded during starboard turning.

scholarly journals ANALYTICAL METHODS FOR CALCULATING FAN AERODYNAMICS

2015 ◽  
Vol 55 (6) ◽  
pp. 373
Author(s):  
Jan Dostal ◽  
Jan Kuzel
Keyword(s):  
Mathematical Model ◽  
Analytical Methods ◽  
Preliminary Design ◽  
Computer Programme ◽  
Aerospace Research ◽  
Model Based ◽  
The Creation ◽  
The Mathematical Model ◽  
Measuring Unit

This paper presents results obtained between 2010 and 2014 in the field of fan aerodynamics at the Department of Composite Technology at the VZLÚ aerospace research and experimental institute in Prague – Letnany. The need for rapid and accurate methods for the preliminary design of blade machinery led to the creation of a mathematical model based on the basic laws of turbomachine aerodynamics. The mathematical model, the derivation of which is briefly described below, has been encoded in a computer programme, which enables the theoretical characteristics of a fan of the designed geometry to be determined rapidly. The validity of the mathematical model is assessed continuously by measuring model fans in the measuring unit, which was developed and manufactured specifically for this purpose. The paper also presents a comparison between measured characteristics and characteristics determined by the mathematical model as the basis for a discussion on possible causes of measured deviations and calculation deviations.

Analytical Study of Hydro-Pneumatic Processes for Gorlov's Power System

1994 ◽  
Vol 208 (1) ◽  
pp. 67-70
Author(s):  
A I Ryazanov
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Power System ◽  
Analytical Study ◽  
Model Tests ◽  
Air Pressure ◽  
Pneumatic Power ◽  
Time Required ◽  
The Mathematical Model

This paper describes the aerohydrodvnamics of processes in chambers of Gorlov's hydro-pneumatic power system. The mathematical model is developed to determine the main parameters of the processes: water and air velocities, air pressure in the chamber, the periods of time required to fill and empty the chambers and the output of energy during the cycle. The results obtained are in agreement with experimental data and model tests.

Development of a Multifactor Regression Model of Ship Maneuvering Forces Based on Optimized Captive-Model Tests

2006 ◽  
Vol 50 (04) ◽  
pp. 311-333 ◽  
Author(s):  
S. Sutulo ◽  
C. Guedes Soares
Keyword(s):  
Experimental Design ◽  
Polynomial Regression ◽  
Design Method ◽  
Model Tests ◽  
Ship Maneuvering ◽  
Captive Model Tests ◽  
Experimental Design Method ◽  
Force Moment ◽  
Force Components ◽  
Multifactor Regression

The paper provides the results of model tests planned with an optimized experimental design method. Captive-model tests have been carried out according to such a design on a computerized planar-motion carriage with a model of a fast catamaran with five varying factors (drift angle, rate-of-yaw amplitude, sinkage, trim and heel angles) and with all six force/moment components measured at each run. The measured values were used after preprocessing for construction of polynomial regression models for all force components acting upon the catamaran's hulls. It is demonstrated that the optimized experimental design method allows rather complicated mathematical models for maneuvering hydrodynamics forces to be obtained from captive model tests at a reasonable level of effort.

scholarly journals Numerical Estimation of Hull Hydrodynamic Derivatives in Ship Maneuvering Prediction

2021 ◽  
Vol 28 (2) ◽  
pp. 46-53
Author(s):  
Radosław Kołodziej ◽  
Paweł Hoffmann
Keyword(s):  
Model Tests ◽  
Circular Motion ◽  
Computational Method ◽  
Design Stage ◽  
Hydrodynamic Characteristics ◽  
Ship Maneuvering ◽  
Hydrodynamic Derivatives ◽  
Captive Model Tests ◽  
Ship Maneuverability ◽  
Free Running

Abstract Prediction of the maneuvering characteristics of a ship at the design stage can be done by means of model tests, computational simulations or a combination of both. The model tests can be realized as a direct simulation of the standard maneuvers with the free running model, which gives the most accurate results but is also the least affordable, as it requires a very large tank or natural lake, as well as the complex equipment of the model. Alternatively, a captive model test can be used to identify the hydrodynamic characteristics of the hull, which can be used to simulate the standard maneuvers with the use of dedicated software. Two types of captive model tests are distinguished: circular motion tests (CMT) and planar motion mechanism tests (PMM). The paper presents an attempt to develop a computational method for ship maneuverability prediction in which the hydrodynamic characteristics of the hull are identified by means of computational fluid dynamics (CFD). The CFD analyses presented here directly simulate the circular motion test. The resulting hull characteristics are verified against the available literature data, and the results of the simulations are verified against the results of free running model tests. Reasonable agreement shows the large potential of the proposed method.

scholarly journals DIESEL SUPPLY PLANNING FOR OFFSHORE PLATFORMS BY A MATHEMATICAL MODEL BASED ON THE VEHICLE ROUTING PROBLEM WITH REPLENISHMENT

2016 ◽  
Author(s):  
Rodrigo De Alvarenga Rosa ◽  
Henrique Fiorot Astoures ◽  
André Silva Rosa
Keyword(s):  
Mathematical Model ◽  
Vehicle Routing ◽  
Vehicle Routing Problem ◽  
Oil And Gas ◽  
Offshore Platforms ◽  
Oil Exploration ◽  
Routing Problem ◽  
Model Based ◽  
Supply Planning ◽  
The Mathematical Model

Oil exploration in Brazil is mainly held by offshore platforms which require the supply of several products, including diesel to maintain its engines. One strategy to supply diesel to the platforms is to keep a vessel filled with diesel nearby the exploration basin. An empty boat leaves the port and goes directly to this vessel, then it is loaded with diesel. After that, it makes a trip to supply the platforms and when the boat is empty, it returns to the vessel to be reloaded with more diesel going to another trip. Based on this description, this paper proposes a mathematical model based on the Vehicle Routing Problem with Intermediate Replenishment Facilities (VRPIRF) to solve the problem. The purpose of the model is to plan the routes for the boats to meet the diesel requests of the platform. Given the fact that in the literature, papers about the VRPIRF are scarce and papers about the VRPIRF applied to offshore platforms were not found in the published papers, this paper is important to contribute with the evolution of this class of problem, bringing also a solution for a real application that is very important for the oil and gas business. The mathematical model was tested using the CPLEX 12.6. In order to assess the mathematical model, tests were done with data from the major Brazilian oil and gas company and several strategies were tested.DOI: http://dx.doi.org/10.4995/CIT2016.2016.2217

The Converter Steelmaking End Point Prediction Model Based on RBF Neural Network

2014 ◽  
Vol 577 ◽  
pp. 98-101
Author(s):  
Xian Liang Dong ◽  
Shi Dong
Keyword(s):  
Neural Network ◽  
Mathematical Model ◽  
Prediction Model ◽  
Carbon Content ◽  
Rbf Neural Network ◽  
Converter Steelmaking ◽  
Prediction Problem ◽  
Model Based ◽  
End Point ◽  
The Mathematical Model

The mathematical model of convert steelmaking end point prediction model based on RBF(Radical Basis Function) is presented in this paper. According to the end point prediction problem of the converter steelmaking production prediction problem, we establish the forecast model of converter steelmaking process which describes the relationship between variables such as hot metal quality, oxygen blowing, the quality of the cooling agent and additives etc. and the end point molten steel temperature and carbon content. The prediction system is multidimensional and nonlinear. The model between variables and the target is unknown. For this situation, this paper applies RBF neural network to forecast target, establishing the prediction model based on RBF neural network. So as to obtain the variables and the mathematical model between steel endpoint temperature and carbon content.

scholarly journals Simulation of the Distribution of Nanoplates in a Liquid

2021 ◽  
Vol 27 (4) ◽  
pp. 647-655
Author(s):  
A. M. R. Al-Mashhadani ◽  
V. F. Pershin
Keyword(s):  
Mathematical Model ◽  
Physical Model ◽  
Critical Concentration ◽  
Solid Particles ◽  
The Real ◽  
Model Based ◽  
Real Process ◽  
Layered Crystals ◽  
The Mathematical Model

The general regularities of exfoliation of layered crystals are considered. A physical model based on the analogy of the spatial packing of polydisperse spherical solid particles is proposed to simulate the distribution of nanoplates in a liquid. Mathematical dependences have been obtained for calculating the critical concentration of aggregation of nanoplates, using graphene as an example. The verification of the adequacy of the mathematical model to the real process was carried out.

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