Drag equation
How is drag calculated?
The drag equation states that drag D is equal to the drag coefficient Cd times the density r times half of the velocity V squared times the reference area A. For given air conditions, shape, and inclination of the object, we must determine a value for Cd to determine drag.
How is drag force calculated on a car?
The drag force is generally modeled as: D = 0.5•rho•V^2•S•Cd; where tho is the air density, V is basically the speed of the car, S is the frontal area of the car if we assume that the wake drag is dominant, and Cd is the parasitic drag coefficient.
What is meant by drag force?
Drag is the aerodynamic force that opposes an aircraft’s motion through the air. Drag is generated by the difference in velocity between the solid object and the fluid. There must be motion between the object and the fluid. If there is no motion, there is no drag.
What are the 3 types of drag?
This includes the displacement of the air by the aircraft, turbulence generated in the airstream, or a hindrance of air moving over the surface of the aircraft and airfoil. There are three types of parasite drag: form drag, interference drag, and skin friction.
Is drag a friction?
In fluid dynamics, drag (sometimes called air resistance, a type of friction, or fluid resistance, another type of friction or fluid friction) is a force acting opposite to the relative motion of any object moving with respect to a surrounding fluid.
What factors affect drag?
Drag is influenced by other factors including shape, texture, viscosity (which results in viscous drag or skin friction ), compressibility, lift (which causes induced drag ), boundary layer separation, and so on.
What is an example of drag force?
Air resistance is an example of the drag force , which is force that objects feel when they move through a fluid (liquid or gas). Similar to kinetic friction , drag force is reactive because it only exists when the object is moving and it points in the opposite direction to the object’s motion through the fluid.
How does drag affect a car?
Aerodynamic drag increases with the square of speed; therefore it becomes critically important at higher speeds. Reducing the drag coefficient in an automobile improves the performance of the vehicle as it pertains to speed and fuel efficiency. There are many different ways to reduce the drag of a vehicle.
Is gravity a drag force?
The drag force acts upward and is proportional to the area and the square of the velocity of the falling sphere. The gravity force acts downward and is proportional to the mass of the sphere; is the acceleration due to gravity.
What is the normal contact force?
In mechanics, the normal force. is the component of a contact force that is perpendicular to the surface that an object contacts. For example, the surface of a floor or table that prevents an object from falling.
Is Buoyant a force?
Buoyancy is the force that causes objects to float. It is the force exerted on an object that is partly or wholly immersed in a fluid. Buoyancy is caused by the differences in pressure acting on opposite sides of an object immersed in a static fluid.
What is minimum drag speed?
Minimum Drag Speed The speed at which minimum drag occurs is the same as the point at which max L/D or minimum D/L occurs.
Does drag depend on mass?
Drag depends directly on the mass of the flow going past the aircraft. The drag also depends in a complex way on two other properties of the air: its viscosity and its compressibility. These factors affect the wave drag and skin friction which are described above.