Darrieus turbine has a vertical-axis configuration that is suitable for current from any direction. Placing a circular flow disturbance in front of the turbine can influence the performance. This study wants to investigate the positioning of the flow disturbance to find the best configuration. The study method used numerical simulation with Computational Fluid Dynamics (CFD) software. There are three variations of the cylinder position in front of the turbine with the angle of 0°, 60°, and -60°. As a result, the configuration can improve or disrupt the performance depending on the position installation. In position 0°, the performance was a decrease of 18%. The best performance is at the flow disturbance position of -60°. The maximum coefficient of power (Cp) value of the turbine was 0.19, with increasing of 27%. Therefore, it is recommended to use the position of -60° in front of the turbine.