Computational Fluid Dynamics (CFD) simulations have been conducted to investigate the performance of a predetermined propeller-based hydrokinetic turbine design in staggered and non-staggered placements for river applications. Actual turbine models were used instead of low fidelity actuator line or actuator disks for CFD simulations to achieve more reliable results. The κ-ω Shear Stress Transport (SST) turbulence model was employed to resolve wall effects on turbine surface and to determine wake interactions behind the turbines. The wake interaction behind the upstream turbine causes significant drop on downstream turbine performance within non-staggered configuration. The upstream turbines in both staggered and non-staggered placement offers the same relative power of 0.96, while the relative power for downstream turbine is 0.98 for staggered installment and 0.16 for inline placement.