  Specific dark energy models with linear inhomogeneous time-dependent equation
of state, within the framework of 4d Friedman-Robertson-Walker (FRW) cosmology,
are investigated. It is demonstrated that the choice of such 4d inhomogeneous
fluid models may lead to a brane FRW cosmology without any explicit account of
higher dimensions at all. Effectively, we thus obtain a brane dark energy
universe without introducing the brane concept explicitly. Several examples of
brane Rip cosmology arising from 4d inhomogeneous dark fluid models are given.
