Drag

The pressure variation associated with flow separation causes

• Skin friction drag

• Form drag

• Separation drag

• Viscous drag

Which type of drag depends on Reynolds number?

• Skin friction drag

• Form drag

The presence of high-velocity, high momentum fluid in the turbulent boundary layer causes the flow to proceed further downstream along the cylinder surface before separation occurs. This produces

• A smaller zone of low pressure, thus, lower drag coefficient.

• A smaller zone of low pressure, thus, higher drag coefficient.

• A larger zone of low pressure, thus, lower drag coefficient.

• A larger zone of low pressure, thus, higher drag coefficient.

Surface roughness will force the boundary layer to become turbulent at

• Higher Reynolds number, leading to larger drag.

• Higher Reynolds number, leading to smaller drag.

• Lower Reynolds number, leading to larger drag.

• Lower Reynolds number, leading to smaller drag.

The vortex shedding frequency depends on a π-group called the

• Reynolds number

• Strouhal number

• Mach number

• Weber number

In the context of calculating the drag force for a circular cylinder of length L and diameter d, the formula for the projected area is: A = πdL.

• True

• False