The thermal stability of mass-loaded flows

Department of Physics and Astronomy, The University of Leeds, Woodhouse Lane, Leeds LS2 9JT, UK

Corresponding author: J. M. Pittard, jmp@ast.leeds.ac.uk

Received: 15 May 2003
Accepted: 23 June 2003

Abstract

We present a linear stability analysis of a flow undergoing conductively-driven mass-loading from embedded clouds. We find that mass-loading damps isobaric and isentropic perturbations, and in this regard is similar to the effect of thermal conduction, but is much more pronounced where many embedded clumps exist. The stabilizing influence of mass-loading is wavelength independent against isobaric (condensing) perturbations, but wavelength dependent against isentropic (wave-like) perturbations. We derive equations for the degree of mass-loading needed to stabilize such perturbations. We have also made 1D numerical simulations of a mass-loaded radiative shock and demonstrated the damping of the overstability when mass-loading is rapid enough.