ISSN 0010-5082, Combustion, Explosion, and Shock Waves, 2018, Vol. 54, No. 3, pp. 364–369.
Pleiades Publishing, Ltd., 2018.
Original Russian Text
Triggering Detonation in an Annular Flow Chamber
D. V. Voronin
Published in Fizika Goreniya i Vzryva, Vol. 54, No. 3, pp. 124–130, May–June, 2018.
Original article submitted September 25, 2017; revision submitted November 7, 2017.
Abstract: The Navier–Stokes equations were used to carry out the numerical modeling of chemi-
cally reactive gas ﬂow in an annular ﬂow chamber. The model was based on laws of conservation of
mass, momentum, and energy for nonstationary two-dimensional compressible gas ﬂow in the case
of axial symmetry with a tangential component of the gas velocity. Viscosity, thermal conductivity,
and turbulence were taken into account. Fuel and oxidizer were fed into the chamber separately,
and heat release in the chemical reaction zone was largely determined by the rate of turbulent
mixing of the gas components. The possibility of burning out of the mixture in the chamber was
demonstrated numerically. Detonation failure can occur if reagents temporarily cease to be fed into
thechamber,whichcanbecausedbyhighpressure in the reaction zone. With short combustion
chamber lengths, there are the underburning of fuel and the release of unreacted hydrogen into
Keywords: annular ﬂow chamber, ignition, turbulence, gas, temperature, detonation, under-
burning of fuel.
The problem of designing an engine based on a det-
onation method of fuel burning is quite urgent these
For the ﬁrst time, the diagram of such a jet engine
can be found in . Modern experimental and theoret-
ical developments on this problem are described in .
The determination of optimal operation regimes of a
chamber requires the creation of detailed mathematical
models that describe the process of fuel burning in the
chamber. This, in particular, was described in . The
triggering of a detonation process in such devices is a
complex and understudied mechanism. For example,
there is a possibility of spontaneous ignition of gas in
the chamber, when its temperature is yet signiﬁcantly
lower than the ignition temperature, which may cause
an explosion of the gas mixture in the entire volume.
This complicates the search for optimal regimes. For a
vortex chamber, this problem was theoretically studied
in , where ignition was described by the occurrence
of hot spots in the boundary layers of the walls of the
Lavrent’ev Institute of Hydrodynamics, Siberian Branch,
Russian Academy of Sciences, Novosibirsk, 630090 Russia;
chamber due to inhomogeneity of the ﬁelds of thermo-
dynamic parameters. Along with the vortex chamber,
the number of possible types of the combustion chamber
should include a ﬂow chamber, where oxidizer arrives
as a continuous ﬂow and fuel is injected into the ﬂow
This paper is devoted to a theoretical study of the
initial stage of triggering of detonation in a ﬂow cham-
ber and determination of factors aﬀecting this process.
FORMULATION OF THE PROBLEM
Let us consider gas-dynamic ﬂow in a ﬂow chamber
(Fig. 1). The chamber is a cylinder 40 mm in diame-
ter, and the length of the chamber L is varied. The
mixture burns in a narrow annular channel near the
outer wall of the chamber, and the width of the channel
is 5 mm. Fuel and oxidizer are fed into the chamber
separately and mixed already inside the chamber. Oxy-
gen is fed into the channel from a receiver through a
. The fuel (hydrogen) enters the chamber
through the nozzles on a surface S
. Gas detonation
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