Homework Question on The Drag Force
- Define drag.
- Identify and explain in layman’s terms the concept of the various drag forces+ why they occur.
- Explain the main component of drag with particular reference to those created through pressure phenomena and those created through skin friction.
- Analyze other forms of drag such as wave, form, pressure, skin friction, parasite, and wave.
Homework Answer on The Drag Force
Drag is the force of resistance associated with any physical body moving through a fluid. When an object is propelled in the air, or a body moves through a liquid like water, there is a force, drag force that opposes the forward motion and it is usually parallel to the speed of the fluid flow. The opposition of the motion is as a result of forces that fluid and objects exert on each other.
Concept of drag using layman’s terms
The drag force associated with an aircraft is called aerodynamic drag or air resistance. Air is a fluid characterized by indefinite shape. Air takes the shape of on objects, in this case, an aircraft. Fluids yield their space easily as compared to other material like solids where there is need of application of a destructive force. The velocity, however, changes in such conditions. Drag is as a result of air resisting changes of its velocity upon encountering a moving body like an aircraft. Aircraft fly by the help of Bernoulli principle which states that pressure reduces with increasing air velocity.
The wing generates lift because of the difference in air velocity and pressure. Air on top goes faster as compared to air at the bottom. The moving plane creates regions of separated flow which generate air resistance. This refers to the smooth flow of air as it comes in contact with the aircraft’s wing, and then suddenly breaks free of the surface resulting in a chaotic flow. The greater the region of separation, the greater the drag. This is called pressure drag caused by compressing together of air particles on the front of a plane and creating more space at the back. Air separates away in front of the surface and begins to swirl creating a turbulent flow.