Bernoulli's equation for flow normal to a streamline explains how pressure varies across curved streamlines due to the outward centrifugal forces induced by the fluid's curvature. The pressure is higher on the inner side of the curve, near the center of curvature, and decreases outward to balance these centrifugal forces.

The pressure difference depends on the fluid's velocity and radius of curvature. The pressure variation is minimal in flows with nearly straight streamlines. However, the pressure difference becomes significant in sharply curved flows, such as vortices, pipe bends, or around sharp structures. This effect is expressed as:

Integrating this relationship and assuming the flow is steady, inviscid, and incompressible, Bernoulli's equation normal to the streamline is derived:

Hydraulic structures like spillways and curved channels rely on accurate pressure predictions to ensure structural integrity under high-velocity flows. Similarly, pressure calculations guide the design of pipe systems with bends, to prevent failure due to excessive forces. The concept also applies to wind flows around civil structures such as buildings and bridges, where pressure differences caused by curved streamlines must be considered to avoid instability or damage during high winds.