SYNOPTIC: Two-Dimensional Potential Flow Theory for Multiple Bodies in Small Amplitude Motion

AIAA Journal ◽  
1970 ◽  
Vol 8 (11) ◽  
pp. 1943-1943
Author(s):  
J.P. Giesing
Keyword(s):  
Potential Flow ◽  
Small Amplitude ◽  
Flow Theory ◽  
Two Dimensional ◽  
Potential Flow Theory

On the Application of Linearized Theory to Multi-Element Aerofoils Part I: Tandem Flat Plate Aerofoils

1983 ◽  
Vol 34 (1) ◽  
pp. 46-60 ◽  
Author(s):  
G.D. Watt ◽  
G.V. Parkinson
Keyword(s):  
Flat Plate ◽  
Potential Flow ◽  
Flow Theory ◽  
Two Dimensional ◽  
Potential Flow Theory ◽  
Linearized Theory ◽  
Good Agreement ◽  
Hand Calculator

SummaryA linearized two-dimensional incompressible potential flow theory for two-element uncambered tandem aerofoil sections is developed. It leads to formulas for lift and moment which can be calculated rapidly on a programmable hand calculator, and which reduce, when the two aerofoil elements come together, to the familiar thin-aerofoil formulas for an aerofoil with a simple flap. The theory is shown to give lift and moment predictions which are in good agreement with predictions of numerical potential flow theory.

A Two-Dimensional Experimental and Numerical Study of Moonpools With Recess

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Senthuran Ravinthrakumar ◽  
Trygve Kristiansen ◽  
Babak Ommani
Keyword(s):  
Potential Flow ◽  
Numerical Study ◽  
Domain Boundary ◽  
Flow Theory ◽  
Mode Shapes ◽  
Linear Potential ◽  
Two Dimensional ◽  
Potential Flow Theory ◽  
Mode Behavior ◽  
Piston Mode

Abstract Moonpool resonance is investigated in a two-dimensional setting in terms of regular, forced heave motions of a model with moonpool with different rectangular-shaped recess configurations. A recess is a reduced draft zone in the moonpool. Dedicated experiments were carried out. The model consisted of two boxes of 40 cm width each, with a distance of 20 cm between them. Recess configurations varying between 5 cm and 10 cm in length and 5 cm in height were tested. Different drafts were also tested. A large number of forcing periods and five forcing amplitudes were tested. A time-domain boundary element method (BEM) code based on the linear potential flow theory was implemented to investigate the resonance periods, mode shapes, as well as the moonpool response as predicted by the (linear) potential flow theory. Dominant physical effects were discussed, in particular damping due to flow separation from the sharp corners of the moonpool inlet and recess. The effect of the recess on the piston-mode behavior is discussed. The nondimensional moonpool response suggests strong viscous damping at the piston-mode resonance. The viscous BEM (VBEM) simulations demonstrate improvement over inviscid BEM, although further improvement of the method is needed. The VBEM simulations are, in general, in good agreement with the experiments. For the largest recess case, some discrepancies are observed in the amplitude-dependent response amplitude operators (RAOs). The piston-mode shapes are clearly different from the near flat free-surface elevation for a moonpool without recess, consistent with the recently published theory.

Application of Potential Flow Theory to Plane-Strain Extrusion

1967 ◽  
Vol 89 (3) ◽  
pp. 503-511 ◽  
Author(s):  
A. Shabaik ◽  
S. Kobayashi ◽  
E. G. Thomsen
Keyword(s):  
Plane Strain ◽  
Potential Flow ◽  
Flow Line ◽  
Flow Theory ◽  
Flow Fields ◽  
Potential Flow Theory ◽  
Good Agreement

Theoretical and experimental flow fields of several extrusion ratios of lead in plane strain were compared. It was found that, for extrusion ratios where dead metal exists, the agreement between the potential and experimental flow nets was better for small reductions when a modified boundary approaching a flow line was used. It was also found that when the flow changed direction gradually, the potential flow net was in good agreement with the experimental one. The solution obtained is unique and complete.

Passing Ship Effects in Non-Uniform Water Depth

2016 ◽  
Author(s):  
Lilan Zhou ◽  
Ji Yang ◽  
Qian Wang ◽  
Jiangtao Qin
Keyword(s):  
Time Domain ◽  
Potential Flow ◽  
Flow Model ◽  
Flow Theory ◽  
Propagation Model ◽  
Beach Erosion ◽  
Wave Flow ◽  
Generation Model ◽  
Theory Method ◽  
Potential Flow Theory

Waves generated by passing ships have potential adverse impacts on the environment (beach erosion, ecological disturbance, structures damage) and other waterway users (navigations, moored ships) in the coastal and sheltered areas. But issues related to waves of ships were addressed rarely in China until now. Accurate prediction of wash waves is the first step to control the washes from passing ships and it’s significant to reduce the effects of washes. A coupled method is used in this paper to simulate the washes and its effects caused by the passing ship. A potential flow theory method is adopted as the stationary wave generation model; a non-hydrostatic wave flow model is used as the wave propagation model; a time domain method is chosen as the model for simulating the forces and moments of mooring ship. The waves calculated by a potential flow theory method in the near field are used as the input for the non-hydrostatic wave-flow model to obtain the far field waves. A time-domain representation of the wave-cut at the location of the passing vessel is transformed to the frequency-domain and is used as the input for the diffraction computations. Parts of the calculated results are validated experimentally, satisfactory agreement is demonstrated.

scholarly journals EVALUATION OF THE ADDED RESISTANCE AND SHIP MOTIONS COUPLED WITH SLOSHING USING POTENTIAL FLOW THEORY

Brodogradnja ◽  
2016 ◽  
Vol 67 (4) ◽  
pp. 109-122
Author(s):  
Ivana Martić ◽  
◽  
Nastia Degiuli ◽  
Ivan Ćatipović
Keyword(s):  
Potential Flow ◽  
Flow Theory ◽  
Ship Motions ◽  
Added Resistance ◽  
Potential Flow Theory

Study on the Dynamics of the Bubble under the Combined Action of the Bjerknes Effect of the Free Surface and the Buoyancy

2014 ◽  
Vol 644-650 ◽  
pp. 628-631
Author(s):  
Ke Yi Li ◽  
Zhong Cai Pei
Keyword(s):  
Free Surface ◽  
Boundary Element Method ◽  
Boundary Element ◽  
Potential Flow ◽  
Flow Theory ◽  
Motion Direction ◽  
Potential Flow Theory ◽  
Combined Action ◽  
Element Method

When the bubble moves in the vicinity of a free surface, the movement will be affected by the buoyancy and the Bjerknes effect. Blake and Gibson proposed the criterion which determined the motion direction of the jet and the dynamics of bubble. They proposed the jet wouldn’t be formed in the condition that . Based on the potential flow theory, boundary element method (BEM) is used to calculate three typical examples in this paper in order to study the dynamics of the bubble under the combined action of the Bjerknes effect of the free surface and the buoyancy. It is found out during the analysis that the Blake criterion is applicable to predict the conditions that and .

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