scholarly journals Investigation on the optimum distance between the hulls of a Danube Delta passenger catamaran

2019 ◽  
Vol 1 ◽  
pp. 7-14
Author(s):  
George Ciprian Iatan ◽  
Dan Obreja
Keyword(s):  
Experimental Model ◽  
Experimental Analysis ◽  
Experimental Results ◽  
Hydrodynamic Performance ◽  
Design Stage ◽  
Danube Delta ◽  
Towing Tank ◽  
Ship Resistance ◽  
Initial Design ◽  
Optimal Distance

The catamaran resistance is an important hydrodynamic performance that must be studied starting with the initial design stage. In this paper, both theoretical and experimental analysis of a Danube Delta passenger catamaran resistance was developed. The method proposed by Sahoo et al. for catamaran with rounded bilge was applied to estimate the ship resistance. Experimental model tests were performed in the Towing Tank of “Dunarea de Jos” University of Galati, in order to determine the optimal distance between the hulls of the catamaran. Important differences were observed between the theoretical and experimental results.

Experimental Analysis of Five Keel-Hull Combinations

1985 ◽  
Author(s):  
J. Gerritsma ◽  
J. A. Keuning
Keyword(s):  
Experimental Analysis ◽  
Model Tests ◽  
Experimental Results ◽  
Forward Speed ◽  
Hull Form ◽  
Towing Tank ◽  
Side Force ◽  
Performance Predictions

Model tests with five different keels in combination with one particular hull form have been carried out in the Delft Towing Tank. The variations include a plain deep keel, a keel-centre board, a plain restricted draft keel,a "Scheel" keel and a "winglet" keel. Based on the experimental results performance predictions are given for a 63 ft yacht for windspeeds up to 25 knots. The measured side force and resistance as a function of heeling angle, leeway angle and forward speed are used to analyse the relative merits of the considered keel-hull combinations.

scholarly journals Experimental model tests to improve a tanker resistance performance

2021 ◽  
Vol 44 ◽  
pp. 11-14
Author(s):  
Dan Obreja
Keyword(s):  
Experimental Model ◽  
Model Tests ◽  
Experimental Techniques ◽  
Naval Architecture ◽  
Towing Tank ◽  
Ship Resistance ◽  
Design Speed ◽  
Bulbous Bow ◽  
Resistance Performance ◽  
Ship Speed

The ship resistance is one of the most important hydrodynamics performances, being related to the contractual ship speed. The experimental model tests can be used to measure and improve the resistance performance. In this paper, the possibility of using the experimental techniques in order to improve a tanker model resistance is demonstrated, based on a bulbous bow modelling solution. In this context, the results obtained in the Towing Tank of the Naval Architecture Faculty of “Dunarea de Jos” University of Galati, related to a tanker model resistance with and without bulbous bow are presented. The bulbous bow form was realised based on the hydrodynamics principles adapted to the bow forms of the tanker. In the case of the bulbous bow solution, a significant reduction of over 8% of the tanker model resistance was obtained, in the design speed domain.

Pipe Routing using Reinforcement Learning on Initial Design Stage

2020 ◽  
Vol 57 (4) ◽  
pp. 191-197
Author(s):  
Dong-seon Shin ◽  
Byeong-cheol Park ◽  
Chae-og Lim ◽  
Sang-jin Oh ◽  
Gi-yong Kim ◽  
...  
Keyword(s):  
Reinforcement Learning ◽  
Design Stage ◽  
Initial Design ◽  
Pipe Routing

Experimental Study of a Tanker Ship Squat in Shallow Water

2014 ◽  
Vol 66 (2) ◽  
Author(s):  
Mohammadreza Fathi Kazerooni ◽  
Mohammad Saeed Seif
Keyword(s):  
Experimental Study ◽  
Shallow Water ◽  
Experimental Approach ◽  
Model Tests ◽  
Ship Hull ◽  
Experimental Results ◽  
Shallow Waters ◽  
Towing Tank ◽  
Ship Model

One of the phenomena restricting the tanker navigation in shallow waters is reduction of under keel clearance in the terms of sinkage and dynamic trim that is called squatting. According to the complexity of flow around ship hull, one of the best methods to predict the ship squat is experimental approach based on model tests in the towing tank. In this study model tests for tanker ship model had been held in the towing tank and squat of the model are measured and analyzed. Based on experimental results suitable formulae for prediction of these types of ship squat in fairways are obtained.

scholarly journals Development of Design Process Simulator for the Ship Initial Design Stage

2009 ◽  
Vol 9 (0) ◽  
pp. 211-222
Author(s):  
Kunihiro Hamada ◽  
Mitsuru Kitamura ◽  
Souichi Yasui ◽  
Hiroshi Kawasaki
Keyword(s):  
Design Process ◽  
Design Stage ◽  
Initial Design ◽  
Process Simulator

scholarly journals Numerical Simulation and Hydrodynamic Performance Predicting of 2 Two-Dimensional Hydrofoils in Tandem Configuration

2021 ◽  
Vol 9 (5) ◽  
pp. 462
Author(s):  
Yuchen Shang ◽  
Juan J. Horrillo
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Resource Constraints ◽  
Lift Coefficient ◽  
Parametric Method ◽  
Experimental Results ◽  
Hydrodynamic Performance ◽  
Tandem Configuration ◽  
Artificial Neural Network Ann ◽  
Naca 0012

In this study we investigated the performance of NACA 0012 hydrofoils aligned in tandem using parametric method and Neural Networks. We use the 2D viscous numerical model (STAR-CCM+) to simulate the hydrofoil system. To validate the numerical model, we modeled a single NACA 0012 configuration and compared it to experimental results. Results are found in concordance with the published experimental results. Then two NACA 0012 hydrofoils in tandem configuration were studied in relation to 788 combinations of the following parameters: spacing between two hydrofoils, angle of attack (AOA) of upstream hydrofoil and AOA of downstream hydrofoil. The effects exerted by these three parameters on the hydrodynamic coefficients Lift coefficient (CL), Drag Coefficient (CD) and Lift-Drag Ratio (LDR), are consistent with the behavior of the system. To establish a control system for the hydrofoil craft, a timely analysis of the hydrodynamic system is needed due to the computational resource constraints, analysis of a large combination and time consuming of the three parameters established. To provide a broader and faster way to predict the hydrodynamic performance of two hydrofoils in tandem configuration, an optimal artificial neural network (ANN) was trained using the large combination of three parameters generated from the numerical simulations. Regression analysis of the output of ANN was performed, and the results are consistent with numerical simulation with a correlation coefficient greater than 99.99%. The optimized spacing of 6.6c are suggested where the system has the lowest CD while obtaining the highest CL and LDR. The formula of the ANN was then presented, providing a reliable predicting method of hydrofoils in tandem configuration.

scholarly journals A study on the behavior of beam-column connections in precast concrete structures: experimental analysis

2012 ◽  
Vol 5 (6) ◽  
pp. 848-873 ◽  
Author(s):  
M. N. Kataoka ◽  
M. A. Ferreira ◽  
A. L. H. C. El Debs
Keyword(s):  
Experimental Analysis ◽  
Precast Concrete ◽  
Concrete Structures ◽  
Concrete Cover ◽  
Experimental Results ◽  
Hollow Core ◽  
Multistory Buildings ◽  
Cracking Control ◽  
Hollow Core Slab ◽  
Reinforcement Distribution

Due to the large increase in the use of precast concrete structures in multistory buildings, this work covers a study on the behavior of beam-column connection with emphasis on the continuity provided by the slab reinforcement. Two prototypes were tested, each one with a different detail of the continuity reinforcement distribution. In both connections, the steel area used on the concrete cover of the hollow core slab was the same, varying the amount of bars that passed through the column and the ones that were placed adjacent to the column. The experimental results showed that the connection with bars adjacent to the column presented stiffness increase and a better cracking control. According to the classification the two tested connections can be considered semi-rigid.

Design and Experimental Analysis of Novel Refractometer Based on Photoelectric Sensor Technology

2011 ◽  
Vol 383-390 ◽  
pp. 5211-5215
Author(s):  
Yin Lin Li ◽  
Zhong Hua Huang ◽  
Kai Bo Hu
Keyword(s):  
Mathematical Model ◽  
Experimental Analysis ◽  
Differential Method ◽  
Theoretical Solution ◽  
Experimental Results ◽  
Sensor Technology ◽  
Photoelectric Sensor ◽  
Better Than

A novel refractometer based on photoelectric sensor technology and differential method is proposed. Sensing principle and mathematical model are introduced; structure and key parameters of sensing probe are designed through detail calculation. Theoretical solution shows resolution reaches order of 10-5. Preliminary experiments verify the feasibility of the design, experimental results show stability error better than ±1.02×10-4, error caused by temperature is 6.65×10-6/°C.

scholarly journals A comparative review of the resistance of a 37,000 dwt Chemical Tanker based on experimental tests and calculations

2020 ◽  
Vol 1 ◽  
pp. 59-66
Author(s):  
Liviu Crudu ◽  
Radu Bosoancă ◽  
Dan Obreja
Keyword(s):  
Energy Efficiency ◽  
Experimental Tests ◽  
Full Scale ◽  
The Other ◽  
Towing Tank ◽  
Ship Resistance ◽  
Comparative Review ◽  
Cfd Applications ◽  
Energy Efficiency Design Index ◽  
Comparison Of The Results

The evaluation of ship resistance is of paramount importance having a decisive impact on the economic performances and efficiency depending on mission. If new IMO requirements through the Energy Efficiency Design Index (EEDI) are taken into account the necessity to have more and more accurate tools capable to consider the influences of different parameters became mandatory. The availability of towing tank facilities and the full scale trials are the practical means in order to be able to confirm the accuracy of theoretical formulations and to define the limits of CFD applications. Based on the results of the towing tank tests, a direct comparison with the results provided by classical methods and CFD computations can be systematically can be performed. On the other hand, the influences of the modifications operated on the fore part of the ship aretheoretically evaluated and compared with the towing tank results. Consequently, the paper is focused on the comparison of the results evaluated using different tools which have been carried out for a Chemical Tanker built by Constanta Shipyard Romania.

Sign in / Sign up

Export Citation Format

Share Document