Drag crisis

In fluid dynamics, drag crisis is a phenomenon in which drag coefficient drops off suddenly as Reynolds number increases. This has been well studied for round bodies like spheres and cylinders. The drag coefficient of a sphere will change rapidly from about 0.5 to 0.2 at a Reynolds number in the range of 300000. This corresponds to the point where the flow pattern changes, leaving a narrower turbulent wake. The behaviour is highly dependent on small differences in the condition of the surface of the sphere.

External links

• "Simulating Drag Crisis for a Sphere Using Skin Friction Boundary Conditions" (PDF). Retrieved 2008-10-24.
• "Flow past a cylinder: Shear layer instability and drag crisis" (PDF). Retrieved 2008-10-24.