Comparison Final Velosity Between Sailing Boat With a Rigid Airfoil and Cloth Sail

2006 ◽  
Author(s):  
H. Amini ◽  
M. Rad ◽  
A. Fakhraee
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Maximum Velocity ◽  
Design Tools ◽  
Hydrodynamic Calculation ◽  
Velocity Prediction ◽  
Computational Fluid Dynamics Cfd ◽  
Hull Forms ◽  
Sailing Boat ◽  
Experimental Equation

The powering requirement of a ship is one of the most important aspects of naval architecture. Traditionally, ships have been tested for hull resistance using hydrodynamic tank testing. But it is very time consuming, expensive, and has inherent scaling errors. Because of these reasons, today many vessels are sold on the market without any model testing. Another set of design tools are Computational Fluid Dynamics and parametric prediction. Computational Fluid Dynamics (CFD) codes are not yet wholly proven in its accuracy. Parametric predictions contain acquired data for a specific family of hull forms and use key hull parameters to evaluate a particular design. This tool is absolutely validating. In this work, parametric predictions tool has been used for velocity prediction of sailing boats and experimental equation has been used for hydrodynamic and aerodynamic calculation. However in this work from experimental equation from Delft towing tank has been used for hydrodynamic calculation but it is acceptable for more boats and ships. In this work velocity is predicted for a sailing boat with one rigid airfoil and sailing boat with cloth sailing. Rigid airfoil can control the velocity of boat. The maximum velocity occurred in 70 to 120 degree angle of courses. In Final stage, the velocity of boat is compared between sailing boat with rigid airfoil and cloth sail.

scholarly journals EFFECT OF HULL AND ACCOMMODATION SHAPE ON AERODYNAMIC PERFORMANCES OF A SMALL SHIP

2019 ◽  
Vol 18 (4) ◽  
pp. 413-421
Author(s):  
Ninh Cong Toan ◽  
Ngo Van He
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Aerodynamic Performance ◽  
Marine Transportation ◽  
Air Resistance ◽  
Aerodynamic Performances ◽  
Computational Fluid Dynamics Cfd ◽  
Different Shapes ◽  
Small Ship ◽  
Hull Forms

In marine transportation, aerodynamic performance is important for the ships, especially for the small passenger fast ships. It has affected the service speed, air resistance acting on hull, power energy as well as roll, pitch, yaw and stability of the ships. Moreover, the aerodynamic performance also directly affects the passengers, captains or employments who work on the ships. For a bad aerodynamic performance hull shape, it may make an accident in marine transportation. In this paper, the authors present a study on effect of hull shape on aerodynamic performance of a small passenger fast ship by using a commercial Computational Fluid Dynamics (CFD). Several hull forms with different shapes are proposed and computed to show their aerodynamic performances. From the comparison between different CFD results of the ships, the effects of hull shape on aerodynamic performances of the ships  are understood.

The Impact of Relative Position of the High-Rise Buildings on the Wind Flow

2016 ◽  
Vol 820 ◽  
pp. 320-325 ◽  
Author(s):  
Dagmara Čeheľová ◽  
Milan Janák ◽  
Boris Bielek
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Maximum Velocity ◽  
Flow Section ◽  
Wind Flow ◽  
High Rise ◽  
Venturi Effect ◽  
Wind Velocities ◽  
Computational Fluid Dynamics Cfd ◽  
The Impact

The Venturi effect has been defined as the increase in fluid speed or flow rate due to a decrease of the flow section. In the present paper the wind speed conditions in passages between triangular buildings with different distances are studied with Computational Fluid Dynamics (CFD) to investigate the extent to which the Venturi effect is present in the passages. In this paper are considered eight different variants of relative positions of the two high-rise buildings. The variable is a distance between towers. They are investigated maximum wind velocities and the point at which the maximum velocity occurs for each from these variants.

scholarly journals A new formula based on computational fluid dynamics for estimating maximum depth of scour by jets from overflow dams

2014 ◽  
Vol 16 (5) ◽  
pp. 1210-1226 ◽  
Author(s):  
Sherong Zhang ◽  
Bohui Pang ◽  
Gaohui Wang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Maximum Velocity ◽  
Maximum Depth ◽  
Scour Depth ◽  
Absolute Deviation ◽  
Scour Hole ◽  
Computational Fluid Dynamics Cfd ◽  
New Formula ◽  
Lm Algorithm

The prediction of the maximum depth of the scour hole formed downstream of overflow dams is critical in determining the safety of hydraulic structures. Most of the conventional formulae are not able to consider complex hydraulic and morphologic conditions. A new formula for estimating the maximum depth of the scour hole based on computational fluid dynamics (CFD), which can be used to simulate the complicated phenomenon, is proposed. The relationship between the maximum velocity in numerical simulations and the maximum scour depth is reflected in this formula, which is established using the Levenberg–Marquardt (LM) algorithm. The validity of this proposed formula is discussed by comparing this formula with three other conventional formulae. The prediction formula based on CFD is applied to the Wuqiangxi Dam, and the absolute deviation of the predicted maximum scour depth (35.44 m) from the measured depth (36.00 m) is 0.56 m.

Research on Hydrodynamic Characteristics of Underwater Gliding UUV Based on the CFD Technique

2012 ◽  
Vol 479-481 ◽  
pp. 729-732
Author(s):  
Pan Guang ◽  
Bin Hu ◽  
Xiao Xu Du ◽  
Yi Yun Wang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Turbulence Model ◽  
Hydrodynamic Characteristics ◽  
Governing Equations ◽  
Hydrodynamic Calculation ◽  
Depth Study ◽  
Calculation Results ◽  
Computational Fluid Dynamics Cfd

Computational fluid dynamics (CFD) technique is used to calculate and analyze the hydrodynamic characteristics of underwater gliding UUV. Governing equations and turbulence model applied to the hydrodynamic calculation are proposed. Calculation results show that the underwater gliding UUV has a good hydrodynamic characteristics which are relatively close to engineering estimation results. Research in this paper lays the foundation for further in-depth study.

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