How could you decrease the drag on an airplane?
A: Engineers reduce friction drag by making the airplane more streamlined, the wings narrower, or by using new materials that make the surface more smooth, decreasing the ability for the force of drag to effect it. As the roughness and surface area of the airplane decreases the friction drag will decrease.
What can be done to prevent drag?
Some things can be done to reduce pressure drag:
- Using an aero helmet to reduce the low-pressure zone directly behind the head.
- Keeping the body as low as possible so air stays attached as it flows over the back.
What counteracts the drag force for flight?
Thrust works opposite of drag. When the forces are balanced, a plane flies in a level direction.
What happens if drag is greater than thrust?
If thrust is greater than drag, the aircraft will speed up, and subsequently, if drag is greater than the thrust, you’ll slow down. Lift is the force that counteracts the weight of an object in order to keep it in the air.
Does Drag equal lift?
In level flight, lift equals weight and thrust equals drag when the plane flies at constant velocity. Weight, lift, thrust and drag are the acting forces on an airplane. Assuming a straight and level flight, lift must be equal to weight and drag must be equal to thrust.
Does drag affect lift?
Drag acts in a direction that is opposite to the motion of the aircraft. Lift acts perpendicular to the motion.
Does drag increase with lift?
Lift/Drag Ratio Both lift and drag increase as you increase the angle of attack of an airfoil, to a point. Beyond that point drag continues to increase, but lift decreases. The best lift/drag ratio occurs at the angle of attack that gives the most lift for the least drag – usually about 18 degrees angle of attack.
Does parasite drag increase with speed?
As airspeed increases, parasite drag increases, while induced drag decreases. Profile drag remains relatively constant throughout the speed range with some increase at higher airspeeds.
Why does parasite drag increase with speed?
As speed increases, the induced drag decreases, but parasitic drag increases because the fluid is striking the object with greater force, and is moving across the object’s surfaces at higher speed. Each of these drag components changes in proportion to the others based on speed.
Why does drag increase when lift increases?
At low angles, the drag is nearly constant. The effect is called induced drag or drag due to lift. The flow around the wing tips of a finite wing create an “induced” angle of attack on the wing near the tips. As the angle increases, the lift coefficient increases and this changes the amount of the induced drag.
What are the factors that 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 increases induced drag?
To state this another way—the lower the airspeed, the greater the AOA required to produce lift equal to the aircraft’s weight and, therefore, the greater induced drag. The amount of induced drag varies inversely with the square of the airspeed. Conversely, parasite drag increases as the square of the airspeed.
Why does induced drag reduce with speed?
Induced drag decreases with (square of) speed (for constant lift), because at higher speed there is more air to accelerate, so it only needs to be accelerated by less. Induced drag is also independent of cross-section.
How can skin drag friction be reduced?
Friction drag can be reduced by delaying the point at which laminar flow becomes turbulent. This can be accomplished by smoothing the exposed surfaces of the aeroplane by using flush rivets on the leading edges and through painting, cleaning, waxing, polishing or the application of surface coatings.
Why do vortices cause drag?
The higher-pressure air below a wing spills up over the wing tip into the area of lower-pressure air above. These wing tip vortices create a form of pressure drag called vortex drag. Vortices reduce the air pressure along the entire rear edge of the wing, which increases the pressure drag on the airplane.
At what airspeed does minimum drag occur?
Minimum Drag Speed For level flight Lift = Weight, so the required lift at the various airspeeds should be constant. The speed at which minimum drag occurs is the same as the point at which max L/D or minimum D/L occurs.
What are the 4 types of drag?
Types of drag are generally divided into the following categories:
- parasitic drag, consisting of. form drag, skin friction drag,
- lift-induced drag, and.
- wave drag (aerodynamics) or wave resistance (ship hydrodynamics).
What is minimum drag speed?
So the minimum power required (maximum endurance) occurs when is a maximum. Thus the minimum power (maximum endurance) condition occurs at a speed which is 3-1/4 = 76% of the minimum drag (maximum range) condition. The corresponding lift-to-drag ratio is 86.6% of the maximum lift-to-drag ratio.
How do you calculate drag curve?
The drag curve
- The significant aerodynamic properties of aircraft wings are summarised by two dimensionless quantities, the lift and drag coefficients CL and CD.
- The lift and the drag forces, L and D, are scaled by the same factor to get CL and CD, so L/D = CL/CD.