What is the term for the tendency of a fluid jet to stay attached to a convex surface?

What is the term for the tendency of a fluid jet to stay attached to a convex surface?

• A. Coanda effect
• B. Venturi effect
• C. Bernoulli principle
• D. Reynolds effect

Answer: (A)

The tendency of a fluid jet to stay attached to a convex surface is described by the Coanda effect. When a jet exits near a curved surface, surrounding fluid is drawn into the jet (entrainment), creating a region of lower pressure between the jet and the surface. This pressure difference pulls the jet toward the surface and causes it to follow the surface’s contour. The effect depends on the interaction of the jet with the boundary layer and viscosity; as long as the adverse pressure gradient isn’t too strong or the curvature too sharp, the jet remains attached and bends with the surface. In contrast, the Venturi effect refers to a pressure drop that occurs as fluid speeds up through a constricted section of pipe, which isn’t about jet adhesion to a surface. The Bernoulli principle describes the general relationship between velocity and pressure in flowing fluids but doesn’t specifically name the attachment phenomenon. Reynolds number concerns the flow regime (laminar vs turbulent) rather than this jet-surface attachment behavior.

The tendency of a fluid jet to stay attached to a convex surface is described by the Coanda effect. When a jet exits near a curved surface, surrounding fluid is drawn into the jet (entrainment), creating a region of lower pressure between the jet and the surface. This pressure difference pulls the jet toward the surface and causes it to follow the surface’s contour. The effect depends on the interaction of the jet with the boundary layer and viscosity; as long as the adverse pressure gradient isn’t too strong or the curvature too sharp, the jet remains attached and bends with the surface.

In contrast, the Venturi effect refers to a pressure drop that occurs as fluid speeds up through a constricted section of pipe, which isn’t about jet adhesion to a surface. The Bernoulli principle describes the general relationship between velocity and pressure in flowing fluids but doesn’t specifically name the attachment phenomenon. Reynolds number concerns the flow regime (laminar vs turbulent) rather than this jet-surface attachment behavior.