In this paper, we investigate an initial-boundary value problem for a
chemotaxis-fluid system in a general bounded regular domain Ω⊂RN (N∈{2,3}), not necessarily being convex. Thanks to the
elementary lemma given by Mizoguchi & Souplet [10], we can derive a new type of
entropy-energy estimate, which enables us to prove the following: (1) for
N=2, there exists a unique global classical solution to the full
chemotaxis-Navier-Stokes system, which converges to a constant steady state
(n∞,0,0) as t→+∞, and (2) for N=3, the existence of a
global weak solution to the simplified chemotaxis-Stokes system. Our results
generalize the recent work due to Winkler [15,16], in which the domain Ω
is essentially assumed to be convex