Sway, Roll, and Yaw Motion Coefficients Based on a Forward-Speed Slender-Body Theory—Part 1

1981 ◽  
Vol 25 (01) ◽  
pp. 8-15
Author(s):  
Armin Walter Troesch
Keyword(s):  
Cross Coupling ◽  
Added Mass ◽  
Numerical Results ◽  
Slender Body ◽  
Forward Speed ◽  
Coupling Coefficients ◽  
Slender Body Theory ◽  
Damping Coefficients ◽  
The Cross ◽  
Body Theory

The added-mass and damping coefficients for sway, roll, and yaw are formulated for a ship with forward speed. The theory is similar to that given by Ogilvie and Tuck (1969) for the heave and pitch coefficients of a slender ship. Numerical results are presented for the cross-coupling coefficients.

Sway, Roll, and Yaw Motion Coefficients Based on a Forward-Speed Slender-Body Theory—Part 2

1981 ◽  
Vol 25 (01) ◽  
pp. 16-20
Author(s):  
Armin Walter Troesch
Keyword(s):  
Added Mass ◽  
Slender Body ◽  
Forward Speed ◽  
Coupling Coefficients ◽  
Slender Body Theory ◽  
Body Theory ◽  
Theory And Experiment

A comparison between theory and experiment is given for the roll-sway, sway-yaw added-mass, and damping coupling coefficients. The theory was derived by Troesch (1980), who followed an approach similar to that given by Ogilvie and Tuck (1969) for the heave and pitch coefficients. The experiments were presented by the Society of Ship Research of Japan in 1976.

Rods falling near a vertical wall

1977 ◽  
Vol 83 (2) ◽  
pp. 273-287 ◽  
Author(s):  
W. B. Russel ◽  
E. J. Hinch ◽  
L. G. Leal ◽  
G. Tieffenbruck
Keyword(s):  
Integral Equation ◽  
Viscous Fluid ◽  
Numerical Solution ◽  
Vertical Wall ◽  
Numerical Results ◽  
Slender Body ◽  
Asymptotic Results ◽  
Slender Body Theory ◽  
Friction Coefficients ◽  
Body Theory

As an inclined rod sediments in an unbounded viscous fluid it will drift horizontally but will not rotate. When it approaches a vertical wall, the rod rotates and so turns away from the wall. Illustrative experiments and a slender-body theory of this phenomenon are presented. In an incidental study the friction coefficients for an isolated rod are found by numerical solution of the slender-body integral equation. These friction coefficients are compared with the asymptotic results of Batchelor (1970) and the numerical results of Youngren ' Acrivos (1975), who did not make a slender-body approximation.

On the Effect of Short-Crestedness on Ship Motions

1966 ◽  
Vol 10 (03) ◽  
pp. 192-200
Author(s):  
E. O. Tuck
Keyword(s):  
Transfer Function ◽  
Transfer Functions ◽  
Full Scale ◽  
Slender Body ◽  
Ship Motions ◽  
Forward Speed ◽  
Slender Body Theory ◽  
Random Seas ◽  
Body Theory

A simple mathematical example, using the slender-body theory of ship motions, is given to illustrate the nature of errors due to short-crestedness in estimations of ship transfer functions from full-scale measurements in directionally random seas. As expected physically, any transfer function obtained in this manner is a smoothed estimate of the true transfer function which would be observed in a unidirectional sea. Computations of this "pseudotransfer function" are presented for heave and pitch of an idealized ship at zero speed, and the effects of forward speed are discussed briefly.

Lateral Force and Yaw Moment on a Slender Body in Forward Motion at a Yaw Angle

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Ronald W. Yeung ◽  
Robert K. M. Seah ◽  
John T. Imamura
Keyword(s):  
Viscous Flow ◽  
Cross Flow ◽  
Slender Body ◽  
Order Effects ◽  
Forward Motion ◽  
Slender Body Theory ◽  
Flow Equations ◽  
The Cross ◽  
Yaw Angle ◽  
Body Theory

This paper presents a solution method for obtaining the lateral hydrodynamic forces and moments on a submerged body translating at a yaw angle. The method is based on the infinite-fluid formulation of the free-surface random-vortex method (FSRVM), which is reformulated to include the use of slender-body theory. The resulting methodology is given the name: slender-body FSRVM (SB-FSRVM). It utilizes the viscous-flow capabilities of FSRVM with a slender-body theory assumption. The three-dimensional viscous-flow equations are first shown to be reducible to a sequence of two-dimensional viscous-fluid problems in the cross-flow planes with the lowest-order effects from the forward velocity included in the cross-flow plane. The theory enables one to effectively analyze the lateral forces and yaw moments on a body undergoing prescribed forward motion with the possible occurrence of cross-flow separation. Applications are made to several cases of body geometry that are in steady forward motion, but at a yawed orientation. These include the case of a long “cone-tail” body. Comparisons are made with existing data where possible.

Two-Dimensional Apparent Masses for Cross-Flow Sections of Wing-Store Configurations

1982 ◽  
Vol 49 (3) ◽  
pp. 471-475
Author(s):  
M.-K. Huang
Keyword(s):  
Approximate Method ◽  
Cross Flow ◽  
Slender Body ◽  
Two Dimensional ◽  
Aerodynamic Stability ◽  
Slender Body Theory ◽  
Rolling Moment ◽  
Stability Derivatives ◽  
The Cross ◽  
Body Theory

On the basis of the assumption that the external stores are small compared with the wing, an approximate method has been developed for estimation of two-dimensional apparent masses for the cross-flow sections of wing-store combinations. The results obtained may be applicable to the analysis of the effects of the stores on the aerodynamic stability derivatives in slender-body theory. The theory has also been applied to estimate the rolling moment due to sideslip for high-wing configurations. The presented results are in agreement with those of other investigations.

Note on the swimming of slender fish

1960 ◽  
Vol 9 (2) ◽  
pp. 305-317 ◽  
Author(s):  
M. J. Lighthill
Keyword(s):  
Swimming Speed ◽  
Critical Value ◽  
Slender Body ◽  
Vortex Wake ◽  
Frictional Drag ◽  
Slender Body Theory ◽  
Propulsive Efficiency ◽  
Deformable Bodies ◽  
Work Done ◽  
Body Theory

The paper seeks to determine what transverse oscillatory movements a slender fish can make which will give it a high Froude propulsive efficiency, $\frac{\hbox{(forward velocity)} \times \hbox{(thrust available to overcome frictional drag)}} {\hbox {(work done to produce both thrust and vortex wake)}}.$ The recommended procedure is for the fish to pass a wave down its body at a speed of around $\frac {5} {4}$ of the desired swimming speed, the amplitude increasing from zero over the front portion to a maximum at the tail, whose span should exceed a certain critical value, and the waveform including both a positive and a negative phase so that angular recoil is minimized. The Appendix gives a review of slender-body theory for deformable bodies.

Slender-body theory for slow viscous flow

1976 ◽  
Vol 75 (4) ◽  
pp. 705-714 ◽  
Author(s):  
Joseph B. Keller ◽  
Sol I. Rubinow
Keyword(s):  
Integral Equation ◽  
Incompressible Fluid ◽  
Viscous Incompressible Fluid ◽  
Unit Length ◽  
The Body ◽  
Slender Body ◽  
Slow Flow ◽  
Slender Body Theory ◽  
Slow Viscous Flow ◽  
Body Theory

Slow flow of a viscous incompressible fluid past a slender body of circular crosssection is treated by the method of matched asymptotic expansions. The main result is an integral equation for the force per unit length exerted on the body by the fluid. The novelty is that the body is permitted to twist and dilate in addition to undergoing the translating, bending and stretching, which have been considered by others. The method of derivation is relatively simple, and the resulting integral equation does not involve the limiting processes which occur in the previous work.

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