scholarly journals Towing-tank measurement of unsteady wave elevation around two ships in head sea condition and comparison with computational results

2021 ◽  
Vol 234 ◽  
pp. 109277
Author(s):  
Jaehoon Lee ◽  
Yonghwan Kim
Keyword(s):  
Computational Results ◽  
Towing Tank ◽  
Wave Elevation

Fluid Dynamic Loading on Curved Riser Pipes

2003 ◽  
Vol 125 (3) ◽  
pp. 176-182 ◽  
Author(s):  
Anthi Miliou ◽  
Spencer J. Sherwin ◽  
J. Michael R. Graham
Keyword(s):  
Dynamic Loading ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Imperial College ◽  
Computational Results ◽  
Flow Conditions ◽  
Towing Tank ◽  
Riser Pipe ◽  
Flow Directions ◽  
Three Dimensional Simulations

In order to gain a preliminary understanding of the fluid dynamics developed past a curved riser pipe, a numerical investigation into the flow past curved cylinders at a Reynolds number of 100 has been performed. To approximate the flow conditions on curved riser pipes, different velocity profiles and flow directions were applied and the corresponding results compared. In addition, the fluid dynamic loading and the wake structures for curved cylinder flows were investigated. The fully three-dimensional simulations were computed with a spectral/hp element method. The computational results were compared with experiments undertaken in the towing tank facility of the Department of Aeronautics of Imperial College.

STUDY OF FROUDE AND HUGHES METHODS BY NUMERICAL TOWING TANK

2021 ◽  
Vol 153 (A2) ◽  
Author(s):  
Q Gao ◽  
D Vassalos
Keyword(s):  
Free Surface ◽  
Wave Pattern ◽  
Experiment Data ◽  
Towing Tank ◽  
Wave Elevation ◽  
Pressure Resistance ◽  
Viscous Pressure ◽  
Coarse Meshes ◽  
Multi Phase ◽  
Resistance Coefficients

The resistance of a cargo ship is calculated by numerical towing tank. RANSE multi-phase parallel solver with K-Z SSTturbulent model and VOF formulation is applied. Computational results from double model (without free surface) areused to obtain 1+k in Hughes’ method and those with free surface are analyzed by both Froude and Hughes’ approachesto investigate model and full scale correlation. ITTC recommended uncertainty study is carried out to evaluate numericalerror due to grid density. The computed wave elevation, wake distribution and resistance components by fine, mediumand coarse meshes are cross-compared and validated against experiment data where applicable. It is found that gridresolution has most effect on wave pattern. The predicted friction and viscous-pressure resistance coefficients arerelatively grid independent from present numerical simulation.

Bank Effects for KVLCC2

2015 ◽  
Author(s):  
Wim Van Hoydonck ◽  
Serge Toxopeus ◽  
Katrien Eloot ◽  
Karan Bhawsinka ◽  
Patrick Queutey ◽  
...  
Keyword(s):  
Interaction Effects ◽  
Water Model ◽  
Shallow Water Model ◽  
Hull Form ◽  
Surface Modelling ◽  
Towing Tank ◽  
Wave Elevation ◽  
Quay Wall ◽  
Bank Effects ◽  
Water Depths

A study is presented on ship-bank interaction effects in which viscous-flow solvers are used to predict the hydrodynamic forces and moments on the ship. The ship under consideration is the KRISO Very Large Crude Carrier (KVLCC2). For this hull form, Flanders Hydraulics Research (FHR) has conducted shallow water model tests in their towing tank equipped with surface-piercing banks and a vertical quay wall. The forces and moments on the KVLCC2 model were obtained for various water depths and lateral distances to the banks. Additionally, the wave elevation was measured between the quay wall and the ship model. In this study, two different CFD codes are used to predict the loads on the KVLCC2 as a function of the water depth and position in the channel. The effect of propeller suction and free surface modelling on the results is quantified. Furthermore, results are compared with potential flow computations to highlight the benefits of each approach. Additionally, comparisons will be made with CFD results from literature. The paper will show that with careful setup of the computations, reliable predictions of the ship-bank interaction effects can be obtained.

Eigenvalue Problem for the Second Order Differential Equation with Nonlocal

2006 ◽  
Vol 11 (1) ◽  
pp. 13-32 ◽  
Author(s):  
B. Bandyrskii ◽  
I. Lazurchak ◽  
V. Makarov ◽  
M. Sapagovas
Keyword(s):  
Differential Equation ◽  
Eigenvalue Problem ◽  
Variable Coefficient ◽  
Order Differential Equation ◽  
Integral Condition ◽  
Second Order ◽  
Computational Results ◽  
Discrete Method ◽  
Complex Eigenvalues ◽  
Nonlocal Integral Condition

The paper deals with numerical methods for eigenvalue problem for the second order ordinary differential operator with variable coefficient subject to nonlocal integral condition. FD-method (functional-discrete method) is derived and analyzed for calculating of eigenvalues, particulary complex eigenvalues. The convergence of FD-method is proved. Finally numerical procedures are suggested and computational results are schown.

Nickel(II)-Methyl Complexes Adopting Idealized Seesaw Geometries

2019 ◽  
Author(s):  
Ethan A. Hill ◽  
Norman Zhao ◽  
Alexander S. Filatov ◽  
John Anderson
Keyword(s):  
Singlet State ◽  
Strong Field ◽  
Structural Distortion ◽  
Computational Results ◽  
Threefold Symmetry ◽  
Chelating Ligand ◽  
Electronic Stabilization

We report four-coordinate nickel(II)-methyl complexes of tris-carbene borate ligands which adopt rare seesaw geometries. Experimental and computational results suggest the structural distortion from threefold symmetry results from a combination of electronic stabilization of the singlet state, strong field donors, and constrained angles from the chelating ligand.

UJI TARIK HIDRODINAMIKMODEL KAPAL BERSAYAP WiSE DENGAN LAMBUNG DASAR BERSTEP

2013 ◽  
Vol 12 (3) ◽  
Author(s):  
Iskendar Iskendar ◽  
Andi Jamaludin ◽  
Paulus Indiyono
Keyword(s):  
Comparative Study ◽  
Model Test ◽  
Hydrodynamic Model ◽  
Surface Effect ◽  
Center Of Gravity ◽  
Test Results ◽  
Flat Bottom ◽  
Towing Tank ◽  
Test Models ◽  
Wetted Surface Area

This paper describes hydrodynamic model tests of Wing in Surface Effect (WiSE) Craft. These craft  was fitted with  stephull  form in different location on longitudinal flat bottom (stepedhull planning craft) to determine the influences of sticking and porpoising motion performances. These motions are usually occured when the craft start to take-off from water surfaces. The test models with scale of 1 : 7 were comprised of 4 (four) stephull models and 1 (one) non-stephull model  as a comparative study. The hydrodynamic  tests were performed with craft speed of 16 – 32 knots (prototype values) in Towing Tank at UPT. Balai Pengkajian dan Penelitian Hidrodinamika (BPPH), BPPT, Surabaya. The resistance (drag) was measured by dynamo meter and the trim of model (draft changing at fore and aft  of model due to model speed) was measured by trim meter. By knowing the value of model trim, the wetted surface area can be determined. Then, the lift forces were calculated based on these measured values. The model test results were presented on tables and curves.  Test results show that models  with step located far away from center of gravity of the WiSE craft tend to porpoising and sticking condition, except if the step location on the below of these center of gravity. While model without step tends to sticking conditions.

Hybrid Imidazole-Pyridine Derivatives: An Approach to Novel Anticancer DNA Intercalators

2020 ◽  
Vol 27 (1) ◽  
pp. 154-169 ◽  
Author(s):  
Claudiu N. Lungu ◽  
Bogdan Ionel Bratanovici ◽  
Maria Mirabela Grigore ◽  
Vasilichia Antoci ◽  
Ionel I. Mangalagiu
Keyword(s):  
Experimental Data ◽  
Antimicrobial Properties ◽  
Qsar Model ◽  
Therapeutic Effectiveness ◽  
Computational Results ◽  
Pyridine Derivatives ◽  
Quadruplex Dna ◽  
Dna Intercalators ◽  
Structure Activity ◽  
G Quadruplex

Lack of specificity and subsequent therapeutic effectiveness of antimicrobial and antitumoral drugs is a common difficulty in therapy. The aim of this study is to investigate, both by experimental and computational methods, the antitumoral and antimicrobial properties of a series of synthesized imidazole-pyridine derivatives. Interaction with three targets was discussed: Dickerson-Drew dodecamer (PDB id 2ADU), G-quadruplex DNA string (PDB id 2F8U) and DNA strain in complex with dioxygenase (PDB id 3S5A). Docking energies were computed and represented graphically. On them, a QSAR model was developed in order to further investigate the structure-activity relationship. Results showed that synthesized compounds have antitumoral and antimicrobial properties. Computational results agreed with the experimental data.

EHAI: Enhanced Human Microbe-Disease Association Identification

2020 ◽  
Vol 21 (11) ◽  
pp. 1078-1084
Author(s):  
Ruizhi Fan ◽  
Chenhua Dong ◽  
Hu Song ◽  
Yixin Xu ◽  
Linsen Shi ◽  
...  
Keyword(s):  
Microbial Community ◽  
Human Health ◽  
Complex Diseases ◽  
Disease Association ◽  
Computational Results ◽  
Computational Approaches ◽  
Disease Diagnostics ◽  
Disease Associations ◽  
Association Discovery ◽  
Biological Tool

: Recently, an increasing number of biological and clinical reports have demonstrated that imbalance of microbial community has the ability to play important roles among several complex diseases concerning human health. Having a good knowledge of discovering potential of microbe-disease relationships, which provides the ability to having a better understanding of some issues, including disease pathology, further boosts disease diagnostics and prognostics, has been taken into account. Nevertheless, a few computational approaches can meet the need of huge scale of microbe-disease association discovery. In this work, we proposed the EHAI model, which is Enhanced Human microbe- disease Association Identification. EHAI employed the microbe-disease associations, and then Gaussian interaction profile kernel similarity has been utilized to enhance the basic microbe-disease association. Actually, some known microbe-disease associations and a large amount of associations are still unavailable among the datasets. The ‘super-microbe’ and ‘super-disease’ were employed to enhance the model. Computational results demonstrated that such super-classes have the ability to be helpful to the performance of EHAI. Therefore, it is anticipated that EHAI can be treated as an important biological tool in this field.

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