Supercavitating Flow Past Slender Delta Wings

The supercavitating flow past slender delta wings is studied. Theory is developed for a conical flow involving cavities which spring from the leading edges of the delta and cover a part of the top of the wing; the center part of the wing top is assumed to be wetted by a kind of re-entrant jet flow. Results are obtained for the two separate asymptotic cases in which the cavitation number is either very small or very large. The widths of the cavities on the wing upper surface increase with decreasing σ and the lift decreases. It is shown that the upper surface never becomes completely enveloped in a cavity even for σ = 0. Finally, the lift of a fully cavitated wing (σ = 0) is estimated to be approximately 4/10 of its fully wetted lift.

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A Note on Gravity Effects in Supercavitating Flow

Journal of Ship Research ◽

10.5957/jsr.1965.9.1.39 ◽

1965 ◽

Vol 9 (01) ◽

pp. 39-45

Author(s):

R. L. Street

Keyword(s):

Gravity Field ◽

Quantitative Agreement ◽

Cavitation Number ◽

Number Range ◽

First Order ◽

Average Value ◽

Flow Past ◽

Supercavitating Flow ◽

Gravity Effects ◽

Linearized Theory

Two approximations to the linearized theory for supercavitating flow about slender bodiesare applied to the case of flow past a slender wedge in a transverse gravity field. The additional lift and moment forces arising as a result of the gravity field are calculated by theories that are expected to hold when the gravity effects are of first-order smallnessconsistent with the linearization appi'oximations. The lift and moment coefficients obtained from the two approximations are in general quantitative agreement over the most important cavitation-number range. The results obtained confirm the validity of the average-value approximation introduced by Parkin.

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The Effect of a Longitudinal Gravitational Field on the Supercavitating Flow Over a Wedge

Journal of Applied Mechanics ◽

10.1115/1.3641650 ◽

1961 ◽

Vol 28 (2) ◽

pp. 188-192 ◽

Cited By ~ 5

Author(s):

A. J. Acosta

Keyword(s):

Gravitational Field ◽

Drag Coefficient ◽

Froude Number ◽

Cavitation Number ◽

Streamline Flow ◽

Flow Past ◽

Supercavitating Flow ◽

Linearized Theory

The free-streamline flow past a symmetrical wedge in the presence of a longitudinal gravitational field is determined with a linearized theory. The proportions of the cavity depend upon the cavitation number and Froude number. The drag coefficient is likewise affected by gravity, though to a smaller extent.

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Separated Flow Past a Slender Delta Wing at Incidence

Aeronautical Quarterly ◽

10.1017/s0001925900006508 ◽

1973 ◽

Vol 24 (2) ◽

pp. 120-128 ◽

Cited By ~ 8

Author(s):

J E Barsby

Keyword(s):

Delta Wing ◽

Separated Flow ◽

Leading Edge ◽

Vortex Sheet ◽

Simultaneous Equations ◽

Delta Wings ◽

Nested Iteration ◽

Finite Difference Technique ◽

Flow Past ◽

Vortex Systems

SummarySolutions to the problem of separated flow past slender delta wings for moderate values of a suitably defined incidence parameter have been calculated by Smith, using a vortex sheet model. By increasing the accuracy of the finite-difference technique, and by replacing Smith’s original nested iteration procedure, to solve the non-linear simultaneous equations that arise, by a Newton’s method, it is possible to extend the range of the incidence parameter over which solutions can be obtained. Furthermore for sufficiently small values of the incidence parameter, new and unexpected results in the form of vortex systems that originate inboard from the leading edge have been discovered. These new solutions are the only solutions, to the author’s knowledge, of a vortex sheet leaving a smooth surface.Interest has centred upon the shape of the finite vortex sheet, the position of the isolated vortex, and the lift, and variations of these quantities are shown as functions of the incidence parameter. Although no experimental evidence is available, comparisons are made with the simpler Brown and Michael model in which all the vorticity is assumed to be concentrated onto an isolated line vortex. Agreement between these two models becomes very close as the value of the incidence parameter is reduced.

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The problem of jet flow past a contour performing small oscillations

Journal of Applied Mathematics and Mechanics ◽

10.1016/0021-8928(64)90118-2 ◽

1964 ◽

Vol 28 (3) ◽

pp. 700-705

Author(s):

A.V. Kuznetsov

Keyword(s):

Jet Flow ◽

Small Oscillations ◽

Flow Past

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Experiments on Gravity Effects in Supercavitating Flow

Journal of Ship Research ◽

10.5957/jsr.1966.10.2.119 ◽

1966 ◽

Vol 10 (02) ◽

pp. 119-121

Author(s):

T. Kiceniuk ◽

A. J. Acosta

Keyword(s):

Gravitational Field ◽

Froude Number ◽

Flow Past ◽

Supercavitating Flow ◽

Gravity Effects

Experiments on the effect of a transverse gravitational field on the supercavitating flow past a wedge tend to confirm predictions based on linearized free-streamline theory. A small though systematic dependence upon Froude number not accounted for by the existing theory is revealed, however.

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A linearized theory for rotational supercavitating flow

Journal of Fluid Mechanics ◽

10.1017/s002211206300149x ◽

1963 ◽

Vol 17 (4) ◽

pp. 513-545 ◽

Cited By ~ 3

Author(s):

Robert L. Street

Keyword(s):

Shear Flow ◽

Flow Past ◽

Supercavitating Flow ◽

Harmonic Perturbation ◽

Two Dimensional Flow ◽

Slender Bodies ◽

Linearized Theory ◽

Particular Solution ◽

Effects Of Rotation ◽

Rotational Problem

In this paper methods are given for establishing qualitative and quantitative measures of the effects of rotation in supercavitating flows past slender bodies. A linearized theory is developed for steady, two-dimensional flow under the assumption that the flow has a constant rotation throughout. The stream function of the rotational flow satisfies Poisson's equation. By using a particular solution of this equation, the rotational problem is reduced to a problem involving Laplace's equation and harmonic perturbation velocities. The resulting boundary-value problem is solved by use of conformal mapping and singularities from thinairfoil theory. The theory is then applied to asymmetric shear flow past wedges and hydrofoils and to symmetric shear flow past wedges. The presence of rotation is shown to create significant changes in the forces acting on the slender bodies and in the shape and size of the trailing cavities.

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