Spiral-mode instability and the screech-tone effect in supersonic jet flows

摘要

At certain modes of gas-jet outflow (as a rule, themode supersonic underexpanded jet), a powerful discrete component appears in the spectrum of the arising acoustic field. Its amplitude is approximately 40–50% higher than the average level of the continuousspectrum noise created by turbulent pulsations and vortex formations in the jet flow. In foreign publications, this phenomenon was called the “screech-tone effect” (from the English “jet screech”).