Crude oil is one of the major sources for energy production. One barrel could produce up to 50% of gasoline. Almost, 75% of a crude oil barrel can be converted to petroleum products which are the most consumable energy sources over the world. With increase in the energy demand and limited sources of crude oil, it is necessary to acquire new sources for energy production. There has been an increasing interest in biofuel as a source of energy since past decades. Using algae for biofuel production has been drawing more attention in recent years. Literature shows the complications involved in the commercialization of the algae-based biocrude. Among different processes involved in biocrude production, harvesting is one of the most time and cost consuming steps that require further development to obtain more efficient and cost-effective solutions. This MSc thesis research is focused on solving three-dimensional unsteady and steady Navier-Stokes equations numerically to investigate the turbulent flow field going through an open channel algae magnetic separator. The numerical simulation is conducted in StarCCM+, a computational fluid dynamics (CFD) software. An Eulerian multiphase flow model, volume of fluid (VOF) model, is applied to determine to track the shape and position of the interface. Different eddy-viscosity turbulence models such as k-ε and SST k-ω are used to predict the unsteady velocity fluctuations along the algae separator. The grid analysis is conducted to determine the appropriate mesh resolution. The results indicated that using VOF approach using RANS turbulence model and well-resolved grids on the walls obtain a reliable predictive tool for analyzing the flow field going through the studied system. However, validation of the results is required using experimental analysis. The results also established recommendations for improving the design geometry of the algae magnetic separator.