Time decay rate for two 3D magnetohydrodynamics‐ α models

We consider the long time behavior of solutions to the magnetohydrodynamics- α model in three spatial dimensions. Time decay rate in L2-norm of the solution is obtained. Similar results for a generalized Leray- α-magnetohydrodynamics model are also established. As a by-product, an optimal time decay rate for the Navier–Stokes- α model is achieved. Copyright © 2013 John Wiley & Sons, Ltd.