The Common Types of Drag in Aviation
In the realm of aviation, drag is an aerodynamic force that constantly acts against an aircraft as it traverses the sky. As a type of restrictive force, drag opposes the motion of an aircraft, causing it to lose airspeed. There are multiple types of drag that one may experience during a flight operation, and each differs in its source and characteristics. As a pilot will regularly face all types of drag during their career, it can be extremely beneficial to be aware of each type and their cause.
Parasite drag is a common type, resulting from the movement of an object through a fluid such as atmospheric air. As such, parasite drag results from the aircraft body traversing the atmosphere and colliding with air molecules. Generally, parasite drag is classified as either form drag, pressure drag, skin friction drag, or interference drag.
Form drag is a direct result of an object moving through a fluid, and the force acting against the object will differ based on the object’s cross-section. Typically, objects that exhibit a larger cross-section and a blunt shape will see increased form drag, while those with reduced cross-sections and sharper shapes will face much less form drag. To reduce form drag, structures of the aircraft, such as aircraft wing assemblies, are designed with smaller cross-sections and more aerodynamic shapes.
Skin Friction Drag
Skin friction drag is true to its name, resulting from the friction that is formed between the aircraft and atmospheric air. As skin friction stems from the skin of the aircraft fuselage and other structures, those with smoother skin will face lessened skin friction drag while assemblies with rough surfaces will have higher skin friction drag. Due to the nature of skin friction drag, increased aerodynamics can be achieved by smoothing out the surfaces of the aircraft.
Profile drag is simply the combination of form and skin friction drag, acting against the aircraft as it flies.
While many types of drag result directly from the aircraft moving through a fluid, interference drag in particular is caused by two or more flows of air that collide at different speeds. Many structures of the aircraft will disrupt flow and change its speed, and interference can occur when these airflows mix around the wing and fuselage. Generally, combating interference drag is achieved by maintaining a sub-90 degree angle between the wing and fuselage.
Lift Induced Drag
While lift is a crucial aspect of flight that keeps aircraft in the air, such aerodynamic forces also generate various types of drag. To produce the most lift, aircraft will need to maintain a slower speed and a higher angle of attack. As the aircraft increases its angle of attack, the amount of air that pushes the aircraft back is increased, coming in the form of induced drag. Induced drag also comes from the mixture of air above and below the wing, generating vortices at the wing tips. To mitigate such types of drag, aircraft may use winglets or shark-lets.
Wave drag is the final common type of drag, generated while an aircraft is flying at transonic and supersonic speeds. As a result of the immense speed that the aircraft is reaching, disturbances of air known as shock waves are created. These shock waves then generate drag on various aircraft parts, slowing down the vehicle. To best mitigate wave drag, engineers design such high-speed aircraft with sharp nose structures.
With the implementation of certain structure shapes, winglets, and other aircraft parts, many forms of drag can be combated for the means of more efficient flight. ASAP Aviation Procurement is a trusted distributor of aircraft parts, and we can help you secure everything you need with competitive pricing and rapid lead-times. Explore our expansive catalog at your leisure, and our team is always here to assist you with personalized quotes on items you are interested in. At ASAP Aviation Procurement, we are more than just a dependable distributor; we are your strategic sourcing partner for all your operational needs.
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