Anisotropic cosmological models with a perfect fluid and a Lambda term

We consider a self-consistent system of Bianchi type-I (BI) gravitational field and a binary mixture of perfect fluid and dark energy given by a cosmological constant. The perfect fluid is chosen to be the one obeying either the usual equation of state, i.e., p = zeta epsilon, with c [0, 1] or a van der Waals equation of state. Role of the Lambda term in the evolution of the BI Universe has been studied.