Y. Umeda et R. Ishii, OSCILLATION MODES OF UNDEREXPANDED JETS ISSUING FROM SQUARE AND EQUILATERAL TRIANGULAR NOZZLES, The Journal of the Acoustical Society of America, 95(4), 1994, pp. 1853-1857
The oscillation modes of underexpanded jets exhausted from square and
equilateral triangular nozzles were investigated experimentally. Two s
tages were observed for both jets. The oscillation modes corresponding
to these stages were identified by using optical and acoustical metho
ds. The experimental results show that oscillation modes for both jets
are first axisymmetric and then sinuous with increasing jet pressure
ratio. The helical oscillation mode, which appeared for the circular j
et, was not observed in these jets. The hysteresis phenomenon found fo
r the circular jet cannot be seen in these jets.