When an airplane approaches and exceeds the speed of sound, it encounters a phenomenon called "supersonic flow." Several factors contribute to the drag experienced by an aircraft as it breaks the sound barrier:
Shock waves: As an aircraft reaches and exceeds the speed of sound (known as Mach 1), shock waves form. These are intense pressure waves that result from the compression of air molecules. The shock waves generate high-pressure regions, leading to increased drag.
Wave drag: Wave drag is a type of drag caused by the formation of shock waves. When an aircraft moves through the air at supersonic speeds, the shock waves create a considerable amount of drag. This drag force opposes the forward motion of the aircraft and requires additional engine power to overcome.
Compression heating: As an aircraft travels at supersonic speeds, the air in front of it compresses rapidly due to the aircraft's shape and speed. This compression raises the temperature of the air, leading to compression heating. The increased temperature can affect the aircraft's aerodynamics and generate additional drag.
Skin friction drag: Skin friction drag is the resistance created by the friction between the aircraft's surface and the air. At supersonic speeds, the airflow over the aircraft's surface becomes highly turbulent, increasing skin friction drag.
To minimize the effects of drag during supersonic flight, aircraft designers use various techniques. These include employing streamlined designs, reducing the surface area exposed to airflow, using materials that can withstand high temperatures, and employing advanced aerodynamic features such as swept wings and carefully shaped fuselages.
It's worth noting that breaking the sound barrier involves complex aerodynamics and engineering considerations, and specialized aircraft, such as supersonic jets, are designed to manage the challenges associated with supersonic flight and mitigate the effects of drag.