Vector 7 nasa meaning skin#

Along the solid surface, a boundary layer of low energy flow is generated and the magnitude of the skin friction depends on conditions in the boundary layer. For the gas, the magnitude depends on the viscosity of the air and the relative magnitude of the viscous forces to the motion of the flow, expressed as the Reynolds number.

For the solid, a smooth, waxed surface produces less skin friction than a roughened surface. Because the skin friction is an interaction between a solid and a gas, the magnitude of the skin friction depends on properties of both solid and gas.

We can think of drag as aerodynamic friction, and one of the sources of drag is the skin friction between the molecules of the air and the solid surface of the aircraft. Many of the factors also affect lift but there are some factors that are unique to aircraft drag. There are many factors that affect the magnitude of the drag. Drag acts in a direction that is opposite to the motion of the aircraft. Vector Quantityĭrag is a force and is therefore a vector quantity having both a magnitude and a direction. It makes no difference whether the object moves through a static fluid or whether the fluid moves past a static solid object. There must be motion between the object and the fluid. Drag is generated by the difference in velocity between the solid object and the fluid. For drag to be generated, the solid body must be in contact with the fluid. It is not generated by a force field, in the sense of a gravitational field or an electromagnetic field, where one object can affect another object without being in physical contact. It is generated by the interaction and contact of a solid body with a fluid (liquid or gas). How is drag generated?ĭrag is a mechanical force. Drag is generated by every part of the airplane (even the engines!). Home > Beginners Guide to Aeronautics What is Drag?ĭrag is the aerodynamic force that opposes an aircraft’s motion through the air.

Vector 7 nasa meaning