The motion of wind‐driven shells

We present a method for solving problems in which a stellar wind interacts with the surrounding environment through the production of a ‘double radiative shock’ structure. This condition is generally met in problems involving winds ejected from young stars. We describe a method that can be applied to problems of winds with arbitrary time and angular dependence, interacting with a stationary environment with an arbitrary density distribution. We apply the method to the interaction of: a steady wind (with an instantaneous ‘turning‐on’) with a power‐law environmental density stratification, a ‘wind plus jet’ ejection with a toroidal environmental density stratification, and to the interaction of an isotropic wind with a clumpy environment. These three examples illustrate the wide range of possible applications of the proposed method. We also show a comparison between some of our thin‐shell solutions and three‐dimensional isothermal gasdynamic simulations of the flows. These comparisons are used as an evaluation of the applicability of our thin‐shell solutions to the real flows.