  We propose self-similar shocked flow models for certain dynamical evolution
phases of young stellar objects (YSOs), `champagne flows' of H {\sevenrm II}
regions surrounding OB stars and shaping processes of planetary nebulae (PNe).
We analyze an isothermal fluid of spherical symmetry and construct families of
similarity shocked flow solutions featured by: 1. either a core expansion with
a finite central density or a core accretion at constant rate with a density
scaling $\propto r^{-3/2}$; 2. a shock moving outward at a constant speed; 3. a
preshock gas approaching a constant speed at large $r$ with a density scaling
$\propto r^{-2}$. In addition to testing numerical codes, our models can
accommodate diverse shocked flows with or without a core collapse or outflow
and an envelope expansion or contraction. As an application, we introduce our
model analysis to observations of Bok globule B335.
