scholarly journals New exact relations for easy recovery of steady wave profiles from bottom pressure measurements

2013 ◽  
Vol 726 ◽  
pp. 547-558 ◽  
Author(s):  
Didier Clamond
Keyword(s):  
Free Surface ◽  
Wave Profile ◽  
Pressure Measurements ◽  
Bottom Pressure ◽  
Reconstruction Procedure ◽  
Free Surface Wave ◽  
Wave Profiles ◽  
Fixed Point Iterations ◽  
Exact Relations

AbstractThis paper is about the determination of a free surface wave profile from a given pressure distribution at the bottom. For a two-dimensional irrotational steady surface water wave propagating over a flat horizontal bed, this problem is solved analytically in an implicit form. Explicit solutions can be easily obtained numerically via fixed point iterations, whose convergence is outlined mathematically and numerically. This new surface reconstruction procedure does not involve the resolution of a differential or an integral equation, i.e. the surface is given by algebraic local relations. Thus, this formulation permits the free surface recovery in a simpler and more efficient way than previous methods.

Prediction of Ship Motions Via a Three-Dimensional Time-Domain Method Following a Quad-Tree Adaptive Mesh Technique

2020 ◽  
Vol 27 (1) ◽  
pp. 29-38
Author(s):  
Teng Zhang ◽  
Junsheng Ren ◽  
Lu Liu
Keyword(s):  
Free Surface ◽  
Incident Wave ◽  
Time Domain ◽  
Three Dimensional ◽  
Adaptive Mesh ◽  
Wave Profile ◽  
Time Domain Method ◽  
Ship Motions ◽  
Quad Tree ◽  
Mesh Technique

AbstractA three-dimensional (3D) time-domain method is developed to predict ship motions in waves. To evaluate the Froude-Krylov (F-K) forces and hydrostatic forces under the instantaneous incident wave profile, an adaptive mesh technique based on a quad-tree subdivision is adopted to generate instantaneous wet meshes for ship. For quadrilateral panels under both mean free surface and instantaneous incident wave profiles, Froude-Krylov forces and hydrostatic forces are computed by analytical exact pressure integration expressions, allowing for considerably coarse meshes without loss of accuracy. And for quadrilateral panels interacting with the wave profile, F-K and hydrostatic forces are evaluated following a quad-tree subdivision. The transient free surface Green function (TFSGF) is essential to evaluate radiation and diffraction forces based on linear theory. To reduce the numerical error due to unclear partition, a precise integration method is applied to solve the TFSGF in the partition computation time domain. Computations are carried out for a Wigley hull form and S175 container ship, and the results show good agreement with both experimental results and published results.

Zur Thermodynamik der hydrophoben Wechselwirkung; die Systeme Wasser + Glycin+ Harnstoff und Wasser + Alanin+ Harnstoff bei 25 °C / Thermodynamics of Hydrophobie Interaction in the Systems Water + Glycin + Urea and Water + Alanin + Urea at 25 °C

1973 ◽  
Vol 28 (9-10) ◽  
pp. 533-554 ◽  
Author(s):  
Lothar Rafflenbeul ◽  
Wa-Ming Pang ◽  
Hansjürgen Schönert ◽  
Klaus Haberle
Keyword(s):  
Amino Acid ◽  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Pressure Measurements ◽  
Free Enthalpy ◽  
Heat Of Dilution ◽  
Ternary Solutions ◽  
Vapor Pressure Measurements ◽  
Calorimetric Determination

Abstract Isopiestic vapor pressure measurements and calorimetric determination of the heat of dilution have been performed and evaluated with respect to enthalpy, entropy and free enthalpy in the ternary solutions water+ glycin+ urea and water+ alanin + urea. The free enthalpy of transfer for the process: Amino acid from water to water+ urea, which can be derived from these measurements, does not agree with the value calculated from solubility measurements. The reason for this discrepancy and the values of entropy and enthalpy in terms of hydrophobic interaction are discussed. Supplementary measurements of the proton magnetic resonance in these solutions are included.

scholarly journals New exact relations for steady irrotational two-dimensional gravity and capillary surface waves

2017 ◽  
Vol 376 (2111) ◽  
pp. 20170220 ◽  
Author(s):  
Didier Clamond
Keyword(s):  
Free Surface ◽  
Gravity Waves ◽  
Water Waves ◽  
Two Dimensional ◽  
Physical Plane ◽  
Theme Issue ◽  
Nonlinear Water Waves ◽  
Dimensional Gravity ◽  
Irrotational Motion ◽  
Exact Relations

Steady two-dimensional surface capillary–gravity waves in irrotational motion are considered on constant depth. By exploiting the holomorphic properties in the physical plane and introducing some transformations of the boundary conditions at the free surface, new exact relations and equations for the free surface only are derived. In particular, a physical plane counterpart of the Babenko equation is obtained. This article is part of the theme issue ‘Nonlinear water waves’.

Thermisches Verhalten von festem LaAlCl6 und chemischer Transport von LaCl3 mit AlCl3/Thermical Behaviour of Solid LaAlCl6 and Chemical Transport of LaCl3 with AlCl3

1999 ◽  
Vol 54 (11) ◽  
pp. 1410-1416 ◽  
Author(s):  
H. Oppermann ◽  
H. Dao Quoc ◽  
A. Morgenstern
Keyword(s):  
Total Pressure ◽  
Chemical Transport ◽  
Lanthanum Chloride ◽  
Pressure Measurements ◽  
Melting Diagram

The thermodynamical data of solid aluminium lanthanum chloride LaAlCl6 have been obtained by determination of the decomposition equilibria from total pressure measurements. The melting diagram was determined by DTA. The chemical transport of LaCl3 with AlCl3 is suggesting the existence of the gaseous complex LaAl3Cl12. The data are:ΔH(LaAlCl6f,298) =-427,1 ±2,5 kcal/mol, S°(LaAlCl6,f,298) = 61 ±2,5 cal/K-mol,Δ(LaAl3Cl12,g ,298) =-712 ± 7 kcal/mol, S°(LaAl3Cl12,g,298) = 205 ± 3 cal/K-mol.

Determination of in-plane permeability of fiber preforms by the gas flow method using pressure measurements

2003 ◽  
Vol 24 (1) ◽  
pp. 34-44 ◽  
Author(s):  
Sun K. Kim ◽  
Jeremy G. Opperer ◽  
Dae-Hwan Kim ◽  
Isaac M. Daniel
Keyword(s):  
Gas Flow ◽  
Pressure Measurements ◽  
Flow Method ◽  
Fiber Preforms

Response of Liquid in Cylindrical Tank with Rigid Annual Baffle Considering Damping Effect

2011 ◽  
Vol 255-260 ◽  
pp. 3687-3691 ◽  
Author(s):  
Jia Dong Wang ◽  
Ding Zhou ◽  
Wei Qing Liu
Keyword(s):  
Free Surface ◽  
Dynamic Response ◽  
Potential Function ◽  
Natural Frequencies ◽  
Damping Ratio ◽  
Cylindrical Tank ◽  
Generalized Coordinates ◽  
Damping Effect ◽  
Total Potential ◽  
Free Surface Wave

Sloshing response of liquid in a rigid cylindrical tank with a rigid annual baffle under horizontal sinusoidal loads was studied. The effect of the damping was considered in the analysis. Natural frequencies and modes of the system have been calculated by using the Sub-domain method. The total potential function under horizontal loads is assumed to be the sum of the tank potential function and the liquid perturbed function. The expression of the liquid perturbed function is obtained by introducing the generalized coordinates. Substituting potential functions into the free surface wave conditions, the dynamic response equations including the damping effect are established. The damping ratio is calculated by Maleki method. The liquid potential are obtained by solving the dynamic response equations of the system.

Nonlinear Local Analysis of Steady Flow About a Ship

1991 ◽  
Vol 35 (04) ◽  
pp. 288-294
Author(s):  
F. Noblesse ◽  
D. M. Hendrix ◽  
L. Kahn
Keyword(s):  
Free Surface ◽  
Fluid Velocity ◽  
Wave Profile ◽  
Local Analysis ◽  
Experimental Measurements ◽  
Surface Boundary ◽  
Nonlinear Method ◽  
Rapid Variation ◽  
Wigley Hull ◽  
Analytical Expressions

A nonlinear local analysis of the steady potential flow at a ship bow and stern, and more generally at any point along a ship waterline, is presented. The hull boundary condition and the nonlinear kinematic and dynamic free-surface boundary conditions are satisfied exactly, at the actual position of the free surface, in this analysis. The bow-flow analysis shows that the free surface at a ship bow is tangent to the stem. This theoretical result appears to agree with existing experimental measurements of steady bow waves of the Wigley hull. Simple analytical expressions defining the fluid velocity at the bow and the stern, and more generally at any point along the wave profile, in terms of the elevation of the free surface at the corresponding point are also given. These analytical expressions and the available experimental measurements of wave profiles along the Wigley hull show that the velocity of the flow disturbance due to this hull is fairly small compared to the hull speed everywhere along the wave profile except in very small regions around the bow and the stern, where the total fluid velocity is nearly equal to the hull speed in magnitude but directed vertically. Nonlinearities therefore appear to be quite important, although only in very small regions surrounding a ship bow and stern. A genuine nonlinear method of calculation must then be able to represent the very rapid variation in the direction of the fluid velocity occurring within small regions around a ship bow and stern. In particular, a sufficiently fine discretization is required in these regions.

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