ABSTRACT
Entrainment and mixing are problems of major concern when one attempts to
understand, control, or model combustion ows in air-breathing propulsion sys-
tems, as well as in such geophysical problems as the evolution of clouds. A
variety of experimental studies carried out in recent years have illuminated the
connections between the coherent structures found in turbulent shear ows and
entrainment, chemical reaction, and combustion [1{3]. It is important to realize
that in experiments on reacting ows, the heat released is a result of chemi-
cal reactions, and that the rate of such reactions is determined by the amount
of mixing (in the sense of molecule-to-molecule interaction) that takes place.
The mixing itself depends on | and in turn aects, through the chemical reac-
tion | the structure of turbulence in the ow. Turbulence, mixing, and reaction
this cyclical connection between mixing, combustion, and heat release can be
broken, and one may focus on the specic eect on turbulence of substantial
amounts of heat release. With this objective in view, a series of simulations have
been performed here using a pseudospectral method to compute the evolution
of a jet-like ow with volumetric heat injection.
