Types of drag
- 1. AMITY INSTITUTE OF AEROSPACE ENGINEERING TYPES OF DRAG AND METHODS TO REDUCE DRAG Prepared By: Dekkala Vinay A3799221005 Guided By: Dr. Rajesh Kumar Saluja
- 2. Introduction Drag : • Drag is one of the four aerodynamic forces that act on a plane. • The force that resists the movement of an aircraft through the air and is produced when lift is developed is called ‘Drag’. • Drag always acts parallel to the relative wind. AMITY INSTITUTE OF AEROSPACE ENGINEERING
- 3. Types of Drag: There are various types of drag depending upon their sources, They are: • Parasite Drag • Form Drag or Pressure Drag • Skin friction Drag • Profile Drag • Interference Drag • Lift induced Drag • Wave Drag Let’s discuss all these drags one by one. AMITY INSTITUTE OF AEROSPACE ENGINEERING
- 4. Parasite Drag: • Parasite drag is a drag produced due to the motion of an object through a fluid. • Parasite drag occurs due to air molecules. • Parasite drag is classified as form drag or pressure drag, skin friction drag and interference drag. Form Drag or Pressure Drag: • Form drag is produced due to the shape of the object moving through the fluid. It depends on the cross section of an object. • An object with a larger cross section and blunt shape will have a larger form drag whereas an object with a smaller cross section area and a sharper shape will have a lesser form drag. AMITY INSTITUTE OF AEROSPACE ENGINEERING
- 5. AMITY INSTITUTE OF AEROSPACE ENGINEERING Skin Friction Drag: Skin friction drag is a drag produced due to friction between an object (aircraft) & fluid (atmospheric air). The rough surface will have high skin friction drag and conversely a smooth surface will have less skin friction drag. Interference Drag: Interference drag is produced due to the interference of two or more airflows having different speeds. And this drag is produced by the interference of different aircraft parts, that is, due to a mixture of airflow around wing and the airflow around the fuselage. Profile Drag: Profile drag is a sum of the form drag & skin friction drag.
- 6. AMITY INSTITUTE OF AEROSPACE ENGINEERING Lift induced Drag: • The direction of lift is perpendicular to the oncoming airflow towards the aircraft. • Lift induced drag, as the name suggests, is a drag produced due to lift.
- 7. Wave Drag: • Wave drag is generally produced at transonic speed (speed almost equals to speed of sound) & Supersonic speed (speed greater than speed of sound). • Due to high speed of airflow, shock waves are produced. Shockwaves are nothing but the disturbance in the air. • This disturbance increases drag of the aircraft known as wave drag. AMITY INSTITUTE OF AEROSPACE ENGINEERING
- 8. AMITY INSTITUTE OF AEROSPACE ENGINEERING The graph shows the variation of drag…..
- 9. AMITY INSTITUTE OF AEROSPACE ENGINEERING Methods to reduce drag: • Pressure drag can be reduced using smaller cross section area for making wings and by using aerodynamic shape for an airfoil. • Making the aircraft skin smooth will reduce skin friction. • Using winglet or shark-lets at wing tips. • Increasing the Aspect ratio. • Flush-Mounted Rivets. • Gap Seals. • Fairings. • Wheel Pants. • Feathering Propellers. • scientists are still looking for the way to reduce shock wave drag.
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