scholarly journals Sonic‐Boom Pressure‐Field Estimation Techniques

1965 ◽  
Vol 38 (5) ◽  
pp. 910-910 ◽  
Author(s):  
Harry W. Carlson ◽  
Robert J. Mack ◽  
Odell A. Morris
Keyword(s):  
Pressure Field ◽  
Sonic Boom ◽  
Estimation Techniques ◽  
Field Estimation

Sonic‐Boom Pressure‐Field Estimation Techniques

1966 ◽  
Vol 39 (5B) ◽  
pp. S10-S18 ◽  
Author(s):  
Harry W. Carlson ◽  
Robert J. Mack ◽  
Odell A. Morris
Keyword(s):  
Pressure Field ◽  
Sonic Boom ◽  
Estimation Techniques ◽  
Field Estimation

Active sonic boom control

1996 ◽  
Vol 325 ◽  
pp. 1-28 ◽  
Author(s):  
Steven C. Crow ◽  
Gene G. Bergmeier
Keyword(s):  
Acoustic Waves ◽  
Pressure Field ◽  
Field Approximation ◽  
Simple Relation ◽  
Sonic Boom ◽  
Simulation Code ◽  
Sonic Booms ◽  
Supersonic Aircraft ◽  
Velocity Changes ◽  
Algebraic Term

A theory and simulation code are developed to study non-steady sources as means to control sonic booms of supersonic aircraft. A key result is that the source of sonic boom pressure is not confined to the length of the aircraft but occupies an extensive segment of the flight path. An aircraft in non-steady flight functions as a synthetic aperture antenna, generating complex acoustic waves with no simple relation to instantaneous volume or lift distributions.The theory applies linear acoustics to slender non-steady sources but requires no far-field approximation. The solution for pressure contains a term not seen in Whitham's theory for sonic booms of distant supersonic aircraft. The term describes a pressure field that decays algebraically behind the Mach cone and, in the case of steady flight, integrates to a ground load equal to the weight of the aircraft. The algebraic term is separate from those that describe the sonic boom.Two non-steady source phenomena are evaluated: periodic velocity changes (surge), and periodic longitudinal lift redistribution (slosh). Surge can attenuate a sonic boom and covert it into prolonged weak reverberation, but accelerations needed to produce the phenomenon seem too large for practical use. Slosh may be practical and can alter sonic booms but does not, on average, result in boom attenuation. The conclusion is that active sonic boom abatement is possible in theory but maybe not practical.

Lift Produced by a Sonic Boom

1963 ◽  
Vol 67 (636) ◽  
pp. 796-796 ◽  
Author(s):  
A. Sigalla
Keyword(s):  
Pressure Field ◽  
Radial Distance ◽  
Wave Pattern ◽  
Technical Note ◽  
Sonic Boom ◽  
Velocity Perturbation ◽  
Flight Direction ◽  
Apparent Inconsistency ◽  
N Wave ◽  
Asymptotic Forms

The Technical Note by C. H. E. Warren in the September Journal raises a question on the transfer of lift, of an aeroplane in supersonic flight, to the ground. This problem was considered in reference 2. It was shown that, as expected, the resultant of the pressure field produced by the aeroplane is equal to its lift. This apparent inconsistency with the N-wave pattern, predicted by Whitham stems from the fact that most applications of Whitham's theory are based on asymptotic forms for the velocity perturbations. Thus, the formula for the axial velocity perturbation is obtained by allowing (M2— l)l/2r/y to tend to infinity, where M is the flight Mach number, r the radial distance away from the aeroplane, y=x—(M2 — l)1/2, and x is the distance along the aeroplane flight direction. This approximation is valid in the vicinity of the shock waves emanating from the aeroplane.

scholarly journals Acoustic pressure field estimation methods for synthetic schlieren tomography

2019 ◽  
Vol 145 (4) ◽  
pp. 2470-2479 ◽  
Author(s):  
Eero Koponen ◽  
Jarkko Leskinen ◽  
Tanja Tarvainen ◽  
Aki Pulkkinen
Keyword(s):  
Acoustic Pressure ◽  
Pressure Field ◽  
Estimation Methods ◽  
Field Estimation
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