Aerodynamics Forces on a Sail

In this article I will explain the aerodynamic force acting on the sails. This provides a driving force for advancing the ship. Many researchers are beginning to realize how effective wind tunnel tests are effective for sailing sails. Currently, computer programs that use equations called Navier-Stokes hydrodynamic equations are the primary means of calculating the wind flow on a sail. In this way, the following wind tunnel image is constructed. (N.d.) Stanford Yacht researcher searched from (http://syr.stanford.edu/SAILFLOW.HTM).

Lift and drag are part of the total aerodynamic force on the sails and they are resisted by the forces on the water (boat) or the running surface (ice boat or land ship). The sail operates in two basic modes; in the lift-based mode, the sail behaves like a wing, and the airflow is connected to both surfaces; in a drag-based mode, the sail and the parachute It starts in the same way. The role is that the air current is in a different flow and to rotate around the sails. Because of their ability to generate lift (and the ability of the aircraft to resist the resulting transverse forces), Sail allows the yacht to go into the wind. Each sail configuration has a characteristic lift coefficient and an associated drag coefficient that can be experimentally determined and theoretically calculated. Even if the route changes, the yacht will direct his sail at a favorable angle of attack between the entrance of the sail and the apparent wind

Sail force depends on wind speed and direction, and speed and direction of the aircraft. The speed of the aircraft at a given navigation point contributes to the "apparent wind", ie the wind speed and direction measured on the moving aircraft. The apparent wind on the sail creates a total aerodynamic force that can be broken down into resistance - force component in the direction of wind and lift - the force component perpendicular to the apparent wind (90 °). Depending on the alignment between the sail and the apparent wind (angle of attack), lift or drag may be the main driving element. Depending on the set of sails' attack angle against the apparent wind, each sail is powered by a lift-driven lift-off flow or traction-driven separation flow to the sailing ship. Furthermore, when used alone, the sails can interact with each other to produce a force different from the sum of the individual contributions of each sail.