Response of an Operational Turbofan Engine to a Simulated Nuclear Blast

1987 ◽  
Vol 109 (2) ◽  
pp. 121-129 ◽  
Author(s):  
M. G. Dunn ◽  
C. Padova ◽  
R. M. Adams
Keyword(s):  
Shock Waves ◽  
Transient Response ◽  
Incident Shock ◽  
Blast Waves ◽  
Propulsion System ◽  
Maximum Speed ◽  
Turbofan Engine ◽  
Air Breathing ◽  
Ludwieg Tube ◽  
Yaw Angle

This paper describes the results of a measurement program designed to determine the transient response of an air-breathing propulsion system to simulated nuclear blast waves. A Ludwieg-tube facility, incorporating a driver technique consisting of an activating chamber and a nonfrangible diaphragm, was used to create the required shock waves. Detailed measurements were performed at incident shock overpressures of approximately 6.9, 10.3, 13.8, and 17.2 kPa (1.0, 1.5, 2.0, and 2.5 psi). For each of these overpressures, data were obtained for engine speeds of 0, 80, 90, and 100 percent of maximum speed. Typical results are presented for distortion patterns at the fan face for both an extended bellmouth and a S-shaped inlet at either 0 or 20 deg yaw angle.

IMPROVEMENT OF FLAMEHOLDING CHARACTERISTICS BY INCIDENT SHOCK WAVES IN SUPERSONIC FLOW

2002 ◽  
Vol 5 (1-6) ◽  
pp. 330-339 ◽  
Author(s):  
T. Fujimori ◽  
M. Murayama ◽  
J. Sato ◽  
H. Kobayashi ◽  
S. Hasegawa ◽  
...  
Keyword(s):  
Supersonic Flow ◽  
Shock Waves ◽  
Incident Shock

Flow patterns of dual-incident shock waves/turbulent boundary layer interaction

2020 ◽  
Vol 23 (6) ◽  
pp. 931-935
Author(s):  
Xin Li ◽  
Hui-jun Tan ◽  
Yue Zhang ◽  
He-xia Huang ◽  
Yun-jie Guo ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Shock Waves ◽  
Turbulent Boundary Layer ◽  
Flow Patterns ◽  
Incident Shock ◽  
Layer Interaction ◽  
Boundary Layer Interaction

scholarly journals Cascade Optimization Strategy for Aircraft and Air-Breathing Propulsion System Concepts

1997 ◽  
Vol 34 (1) ◽  
pp. 136-139 ◽  
Author(s):  
Surya N. Patnaik ◽  
Thomas M. Lavelle ◽  
Dale A. Hopkins ◽  
Rula M. Coroneos
Keyword(s):  
Propulsion System ◽  
Optimization Strategy ◽  
Air Breathing

scholarly journals Explosion waves and shock waves. IV—Quasi-detonation in mixtures of methane and air

1937 ◽  
Vol 158 (894) ◽  
pp. 348-367 ◽  
Keyword(s):  
Shock Waves ◽  
Detonation Wave ◽  
Practical Importance ◽  
Coal Mines ◽  
Maximum Speed ◽  
Theoretical Interest ◽  
Rapid Motion ◽  
And Shock Waves ◽  
Effects Of Violence

The possibility of detonation in mixtures of methane and air, apart from its theoretical interest, is of practical importance in connexion with the study of explosions in coal mines. Many attempts have been made experimentally to increase the violence of explosion or the intensity of combustion of mixtures of methane and air to see if speeds of flame and effects of violence comparable with those of detonation could be obtained. Mason and Wheeler noted that restrictions in the path of an explosion accelerated the flame, and observed that as the flame of a methane-air mixture passed through the second of two restrictions placed in a 30·5-cm. tube “the development of the detonation wave appeared imminent”. The experiments were continued by Chapman and Wheeler, who obtained a maximum speed of 420 metres per second beyond the restricted section of a tube 5 cm. in diameter. The effect of the restrictions was in their opinion to induce rapid motion in the mixture through which the flame was travelling.

scholarly journals Vectorial dispersive shock waves in optical fibers

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
J. Nuño ◽  
C. Finot ◽  
G. Xu ◽  
G. Millot ◽  
M. Erkintalo ◽  
...  
Keyword(s):  
Shock Waves ◽  
Fiber Optics ◽  
Optical Fibers ◽  
Continuous Wave ◽  
Blast Waves ◽  
Nonlinear Fiber Optics ◽  
Nonlinear Phase ◽  
Perfect Fluids ◽  
Bose Einstein ◽  
Wave Phenomena

Abstract Dispersive shock waves are a universal phenomenon encountered in many fields of science, ranging from fluid dynamics, Bose-Einstein condensates and geophysics. It has been established that light behaves as a perfect fluid when propagating in an optical medium exhibiting a weakly self-defocusing nonlinearity. Consequently, this analogy has become attractive for the exploration of dispersive shock wave phenomena. Here, we observe of a novel class of vectorial dispersive shock waves in nonlinear fiber optics. Analogous to blast-waves, identified in inviscid perfect fluids, vectorial dispersive shock waves are triggered by a non-uniform double piston imprinted on a continuous-wave probe via nonlinear cross-phase modulation, produced by an orthogonally-polarized pump pulse. The nonlinear phase potential imparted on the probe results in the formation of an expanding zone of zero intensity surrounded by two repulsive oscillating fronts, which move away from each other with opposite velocities.

scholarly journals Shock Loading of Closed Cell Aluminum Foams in the Presence of an Air Cavity

2020 ◽  
Vol 10 (12) ◽  
pp. 4128
Author(s):  
Mahesh Thorat ◽  
Shiba Sahu ◽  
Viren Menezes ◽  
Amol Gokhale ◽  
Hamid Hosano
Keyword(s):  
Shock Waves ◽  
Shock Tube ◽  
Shock Loading ◽  
Pressure Rise ◽  
Incident Shock ◽  
Foam Density ◽  
Aluminum Foams ◽  
Closed Cell ◽  
Rigid Walls ◽  
End Wall

It is important to protect assets located within cavities vulnerable to incident shock waves generated by explosions. The aim of the present work is to explore if closed cell aluminum foams can mediate and attenuate incident shocks experienced by cavities. A small cavity of 9 mm diameter and 2 mm length was created within the steel end-wall of a shock tube and exposed to shocks, directly or after isolating by aluminum foam liners. Shock waves with incident pressure of 9–10 bar travelling at a velocity of 1000–1050 m/s were generated in the shock tube. Compared to the no-foam condition, the pressure induced in the cavity was either equal or lower, depending on whether the foam density was low (0.28 g/cc) or high (0.31 to 0.49 g/cc), respectively. Moreover, the rate of pressure rise, which was very high without and with the low density foam barrier, reduced substantially with increasing foam density. Foams deformed plastically under shock loading, with the extent of deformation decreasing with increasing foam density. Some interesting responses such as perforation of cell walls in the front side and densification in the far side of the foam were observed by a combination of scanning electron microscopy and X-ray microscopy. The present work conclusively shows that shocks in cavities within rigid walls can be attenuated by using foam liners of sufficiently high densities, which resist densification and extrusion into the cavities. Even such relatively high-density foams would be much lighter than fully dense materials capable of protecting cavities from shocks.

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