© 2021 Elsevier LtdTurbulent flow fields behind wind turbines are investigated using LES and Actuator Line Model with OpenFOAM on locally clustered Cartesian grids in a parallel computing environment. Wake interactions between two wind turbines in a tandem configuration are simulated and their power productions are evaluated. Model parameters that play a critical role in the accuracy of simulations are first identified and determined by parametric studies. In the selection of the parameters the variation of the local angle of attack along the blade span and the blade load distribution are compared with the fully resolved mesh solutions and the Blade Element-Momentum based QBlade solutions. Wake interactions between two axially aligned turbine rotors are then simulated under non-turbulent and turbulent inflow conditions. The wake recovery behind the upstream turbine and the power loss in the downstream turbine due to the inflow conditions are assessed. The turbulent inflow condition is found to have a significant impact on the velocity deficit in the turbine wake, which increases the power production at the downstream turbine.