scholarly journals Bodies Having Minimum Pressure Drag in Supersonic Flow: Investigating Nonlinear Effects

2004 ◽  
Author(s):  
Karthik Palaniappan ◽  
Antony Jameson
Keyword(s):  
Supersonic Flow ◽  
Nonlinear Effects ◽  
Minimum Pressure ◽  
Pressure Drag

scholarly journals Bodies Having Minimum Pressure Drag in Supersonic Flow: Investigating Nonlinear Effects

2010 ◽  
Vol 47 (4) ◽  
pp. 1451-1454 ◽  
Author(s):  
Karthik Palaniappan ◽  
Antony Jameson
Keyword(s):  
Supersonic Flow ◽  
Nonlinear Effects ◽  
Minimum Pressure ◽  
Pressure Drag

Cowl Shapes of Minimum Drag in Supersonic Flow

1965 ◽  
Vol 69 (650) ◽  
pp. 121-126
Author(s):  
E. Angus Boyd
Keyword(s):  
Supersonic Flow ◽  
Diameter Ratio ◽  
Computer Method ◽  
Impact Pressure ◽  
Axially Symmetric ◽  
Flow Equations ◽  
Minimum Pressure ◽  
Pressure Drag ◽  
General Flow ◽  
Minimum Drag

In part 1 of this paper the shape of an axially symmetric ducted body, of given length and fineness ratio, having minimum pressure drag was derived using the Newtonian impact pressure law. It was shown that this shape closely approximated that found by a computer method of Guderley, Armitage and Valentine which employed the general flow equations. Indeed the two curves could be distinguished only for values of the diameter ratio Δ=di/df, of the initial and final diameters, so small as to be outside the range likely to be used for cowl shapes.

Hypersonic minimum drag forebodies with blunt leading edges

2013 ◽  
Vol 117 (1191) ◽  
pp. 553-557
Author(s):  
J. Pike
Keyword(s):  
Hypersonic Flow ◽  
Axisymmetric Body ◽  
The Body ◽  
Minimum Pressure ◽  
Pressure Drag ◽  
Minimum Drag ◽  
Impact Theory ◽  
Leading Edges

AbstractThe minimum pressure drag of blunt forebodies in hypersonic flow is investigated using Newton’s Impact Theory. It is shown how the minimum drag shape varies with the body slenderness and the amount of blunting. As the blunting increases the drag approaches that of the minimum drag axisymmetric body.

Two-Dimensional Aft Bodies for Minimum Pressure Drag in Supersonic Flow

1976 ◽  
Vol 27 (4) ◽  
pp. 263-269
Author(s):  
P R Viswanath ◽  
R Narasimha
Keyword(s):  
Boundary Layer ◽  
Supersonic Flow ◽  
Sudden Expansion ◽  
Preliminary Design ◽  
Two Dimensional ◽  
Pressure Drag ◽  
Minimum Drag ◽  
Body Drag ◽  
Optimum Profile ◽  
Good Agreement

SummaryThe base pressure correlation proposed earlier by the authors, to take into account the effects of the boundary layer and of the boat-tail angle, is utilised in the design of two-dimensional aft bodies for minimum drag in supersonic flow. The general advantages of boat-tailing are indicated and charts of optimum profile parameters and minimum drag are provided for use in preliminary design. The effects on aft-body drag of possible reversion of the boundary layer at a sudden expansion are discussed, and the relevance of the optimum shapes found to the lifting case is indicated. The calculated optimum geometry is in good agreement with the experimental results of Fuller and Reid.

Mean flows driven by weak eddies in rotating systems

1980 ◽  
Vol 99 (3) ◽  
pp. 655-672 ◽  
Author(s):  
A. D. Mcewan ◽  
R. O. R. Y. Thompson ◽  
R. A. Plumb
Keyword(s):  
Dynamic Pressure ◽  
Nonlinear Effects ◽  
Zonal Flow ◽  
Background Field ◽  
Pressure Drag ◽  
Mean Motion ◽  
Rotating Systems ◽  
Induced Motion ◽  
The Mean ◽  
General Relations

General relations are derived for the forcing of a mean zonal flow in a damped rotating barotropic system through the action of weak eddies. In particular it is found that if the eddies are forced at localized latitudes the induced motion away from these latitudes is likely to be counter to the rotation (i.e. ‘easterly’). Over the forcing latitude the mean motion is always westerly except when the forcing provides a sink of relative momentum. In the case when the background field is deformed topographically to generate eddies the divergence of the Reynolds stress is balanced at lowest order by a dynamic pressure drag, and the mean motion takes the direction of propagation of the forcing.The relations are applied to a linearized Rossby wave field in a viscous fluid driven by a moving system of boundary sources and sinks or hills and hollows. The results are compared with laboratory experiments. All major predictions are confirmed qualitatively, but the discrepancies in detail indicate the influence of nonlinear effects other than those incorporated in the theory.

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