Scalloping (Aerodynamics)

In aerodynamics, scalloping refers to a phenomenon where a structure, like a swept wing, experiences unsteady aerodynamic loads, leading to a wavy or scalloped deformation of its surface. This can occur during flight, especially at high speeds, and is often associated with buffeting or scallop ice.

History and Context

Early Aerodynamics

Modern aerodynamics emerged in the 17th century, but humans have harnessed aerodynamic forces for millennia in sailboats and windmills.

Swept Wings

Swept wings, which are designed to delay the onset of wave drag at high speeds, have been used in aviation since the pioneer days, with investigations into their behavior at high speeds dating back to the 1930s in Germany.

Buffeting

Buffeting, a repeated loading of a structure by unsteady aerodynamic flow, is a phenomenon that can occur during atmospheric ascent, and its severity depends on factors like dynamic pressure, Mach number, angle of attack, and the shape of the vehicle.

Scallop Ice

Scallop ice is a specific type of ice accretion that can occur on swept wings, characterized by a wavy or scalloped shape.

Applications

Scalloping is also relevant in other fields, such as the design of centrifugal impellers, where scallops (intentional cuts) are used to prevent high-cycle fatigue.

Mechanisms and Effects

Unsteady Loads

Scalloping arises from unsteady aerodynamic forces, which can cause a structure to vibrate or deform.

Buffeting

Buffeting, a type of scalloping, can lead to structural fatigue and damage.

Scallop Ice

Scallop ice can significantly impact aircraft performance and safety, especially during icing conditions.

Drag Reduction

In some cases, scalloped surfaces can reduce drag, as seen in the example of humpback whale flippers and wind turbine blades.

Biomimicry

The study of scallops and their shells has inspired biomimetic designs for drag reduction in various applications.