Research output: Contribution to journal › Article

Original language | English |
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Pages (from-to) | 3766-3774 |

Journal | Physics of Fluids |

Volume | 14 |

State | Published - 1 Nov 2002 |

The interaction of turbulence and shock waves is considered
self-consistently so that the back-reaction of the turbulence and its
associated reaction on the turbulence is addressed. This approach
differs from previous studies which considered the interaction of linear
modes with a shock. The most basic model of hypersonic flow, described
by the inviscid form of Burgers' equation, is used. An energy-containing
model which couples the turbulent energy density and correlation length
of the flow with the mean flow is developed. Upstream turbulence
interacting with a shock wave is found to mediate the shock by (1)
increasing the mean shock speed, and (2) decreasing the efficiency of
turbulence amplification at the shock as the upstream turbulence energy
density is increased. The implication of these results is that the
energy in upstream turbulent fluctuations, while being amplified at the
shock, is also being converted into mean flow energy downstream. The
variance in both the shock speed and position is computed, leading to
the suggestion that, in an ensemble-averaged sense, the turbulence
mediated shock will acquire a characteristic thickness given by the
standard deviation of the shock position. Lax's geometric entropy
condition is used to show that as the upstream turbulent energy density
increases, the shock is eventually destabilized, and may emit one or
more shocks to produce a system of multiple shock waves. Finally,
turbulence downstream of the shock is shown to decay in time t according
to t-2/3.

- Hypersonic Flow, Shock Wave Interaction, Shock Waves, Turbulence, Turbulent Flow, Turbulent flows, Shock wave interactions and shock effects, Supersonic and hypersonic flows

ID: 19679002