The utilization of kinetic energy from the river is promising as an attractive alternative to other available renewable energy resources. Hydrokinetic turbine systems are advantageous over traditional dam based hydropower systems with reference to "zero-head" and mobility. Although sharing similar design principles as wind turbine systems, hydrokinetic turbine systems have significant differences in terms of free surface effects and cavitation. In this work, a three-blade horizontal axis hydrokinetic composite turbine system was designed and tested in a water tunnel. Computational fluid dynamics (CFD) simulation was conducted for the chosen hydrofoils and to characterize wake flow behind the hydrofoil, the result was compared with particle image velocimetry (PIV) solutions. A simulation model was developed based on blade element momentum (BEM) theory for the turbine system and comparisons between experiment and simulation were performed. The experimental data includes measurement of tip-speed ratio, torque and power generated by the turbine at various blade pitch settings and water velocities. The results indicate that the developed numerical method provides satisfactory prediction of the performance of the hydrokinetic composite turbine system.