bluntbody

Bluntbody is a term used in aerodynamics to describe a body with a non-pointed, broad nose. In high-speed flows, blunt bodies generate detached bow shocks in front of the surface, unlike slender or pointed shapes that produce attached shocks. The shock separates the flow from the surface, creating a shock layer of hot gas between the wall and the shock.

This configuration results in higher form drag and pressure drag, especially at supersonic and hypersonic speeds, but it also reduces heat transfer to the surface by spreading stagnation heating into the shock layer and mixing it with the surrounding gas. The stand-off distance between the shock and the surface grows with bluntness, altering pressure distribution and boundary-layer behavior.

Blunt bodies are favored for atmospheric entry vehicles and reentry capsules because of their thermal protection advantages and stability; examples include many spacecraft command capsules. However, the increased drag and heavier structures required mean they are less suitable for conventional, high-speed flight where low drag is desired. In design practice, body bluntness is one of the primary levers to manage heat load and deceleration during entry.