Which mechanism causes increased drag on a high-speed train exceeding a critical velocity?

💡 Explanation

Increased drag is a consequence of the transition to turbulence. At high velocities, the Reynolds Number exceeds a critical value, and laminar flow transitions to turbulent flow. The increased mixing of high velocity fluid with low velocity fluid near the surface through turbulent eddies increases the drag rather than compressibility or skin friction effects because of how kinetic energy dissipates.

• Which risk increases when a satellite's orbit introduces strong spacetime curvature?
• Which outcome occurs when the path difference between interfering waves approaches zero?
• Which mechanism initiates constructive interference when two coherent light waves combine?
• Which consequence results when a black hole tidal force compresses turbulent accretion disk plasma?
• Which outcome occurs when excessive non-competitive inhibitor binds an enzyme?
• Which effect does introducing an inert gas at constant volume have on gaseous reaction at equilibrium?