The multiple source feedback of supersonic jet screech, III: Space‐time diagrams applied to the helical mode

2000 ◽  
Vol 108 (5) ◽  
pp. 2588-2588
Author(s):  
Alan Powell
Keyword(s):  
Supersonic Jet ◽  
Space Time ◽  
Multiple Source ◽  
Helical Mode

Sound Sources of Screech Tone Radiated from Circular Supersonic Jet Oscillating in the Helical Mode

2002 ◽  
Vol 1 (4) ◽  
pp. 355-384 ◽  
Author(s):  
Yoshikuni Umeda ◽  
Ryuji Ishii
Keyword(s):  
Wave Front ◽  
Vortical Structure ◽  
Supersonic Jet ◽  
Oscillation Mode ◽  
Shock Cell ◽  
Sound Sources ◽  
Screech Tone ◽  
Mach Cones ◽  
Helical Mode ◽  
Jet Axis

The generation mechanism of the screech tone in the helical oscillation mode is investigated using a series of instantaneous schlieren photographs. From the photographs, six evanescent sound sources are observed as prominent points along the jet axis. These sound sources move along circular orbits in the planes perpendicular to the jet axis and just downstream of the rear edges of each shock cell. The speed of moving sound sources is supersonic and the moving Mach cones generated behind the moving sound sources form the helical-shaped wave front of the screech tone. Existence of the moving Mach cones about the jet axis was confirmed by comparing schlieren photographs and drawings of the envelopes of the moving Mach cones. The helical vortical structure appears to overlap on the envelopes of the moving Mach cones.

Space, Time and Einstein

2002 ◽  
Author(s):  
J. B. Kennedy
Keyword(s):  
Space Time

Supersonic jet spectrometry of chemical species resulting from thermal decomposition of polystyrene and polycarbonate

1992 ◽  
Vol 64 (19) ◽  
pp. 931A-940A ◽  
Author(s):  
Totaro Imasaka ◽  
Masami Hozumi ◽  
Nobuhiko Ishibashi
Keyword(s):  
Thermal Decomposition ◽  
Supersonic Jet ◽  
Chemical Species
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