In the design of sailing yachts, the analysis of aerodynamic forces exerted on sails is very important to predict the performance of propulsion of a ship. To understand the essential flow physics around the sail, a simplified rigid-body sail model is proposed in this study. Four parameters such as free stream velocity, angle of attack, maximum width of sail, and camber length are considered as the independent variables. Lift and drag coefficients are computed with CFD technique using ANSYS-CFX, and the results with the visualization of flow field are analyzed in the viewpoint of fluid dynamics.