Why does drag decrease after Mach 1?

Notice that the wake does not seem as large relative to the body as for the aircraft above at barely above Mach 1. The shockwaves are all off the body at this higher speed. That helps the boundary layer remain attached to the body and lowers the drag coefficient again as the flow becomes more supersonic.

Why does supersonic speed cause more drag?

For supersonic aircraft, this is paramount. When an aircraft redirects incoming air at supersonic airspeeds, it creates shocks. The pressure of the air increases across these shocks and causes “wave drag” on the aircraft. With a stronger shock comes more drag.

Why does drag increase at Mach 1?

The drag-divergence Mach number is usually close to, and always greater than, the critical Mach number. The large increase in drag is caused by the formation of a shock wave on the upper surface of the airfoil, which can induce flow separation and adverse pressure gradients on the aft portion of the wing.

How can wave drag be reduced?

This wave drag can be reduced by incorporating one or more aerodynamic design features such as wing sweep, ultra thin wings, fuselage shape, anti shock bodies and supercritical aerofoils.

Which is faster Mach 1 or Mach 2?

Mach 1 is the speed of sound, which is approximately 760 miles per hour at sea level. An airplane flying less than Mach 1 is traveling at subsonic speeds, faster than Mach 1 would be supersonic speeds and Mach 2 would be twice the speed of sound.

Is supersonic more fuel efficient?

Supersonic aircraft are estimated to burn five to seven times as much fuel per passenger as a regular aircraft, according to the nonprofit International Council on Clean Transportation.

What affects wave drag?

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.

Is wave drag induced drag?

Modern airliners use winglets to reduce the induced drag of the wing. Two additional sources of drag are wave drag and ram drag. As an aircraft approaches the speed of sound, shock waves are generated along the surface. The shock waves produce a change in static pressure and a loss of total pressure.

Has Mach 3 been achieved?

The Blackbird could sustain speeds above Mach 3, with a so far unbroken manned-flight record of Mach 3.3 or 3.5. (The 3.3 record is confirmed, while Mach 3.5 is claimed by pilot Brian Shul to have been achieved while outrunning a missile over Libya in 1986.)

What happens to a bullet at supersonic speeds?

At very high supersonic speeds, the shock waves have a greater amount of separation from the bullet reducing turbulence and drag along its edges. As speeds drop, the amount reduces, turbulence around the bullet and drag increase peaking just above the speed of sound.

How does net drag change with velocity?

Net drag increases as velocity increases. I like to think of it in terms of wind resistance – when you put your hand out the car window at 65 mph versus 25 mph. Married folks might relate it better to the resistance from your spouse when purchasing a $7K bench rifle compared to a $500 Tikka. Its all relative. All this mathematics and computations.

Why does the drag force on a bullet decrease with velocity?

The drag force on the bullet does not really go down. It basically increases with the -square- of the velocity. Only after this is computed, the drag coefficient is applied to cater for the variation from pure quadratic drag increase. Take for example a bullet that has a cd of 0.660 at 1600 fps and 0.607 at 2200 fps (cd goes down).