According to the Bernoulli principle, what happens to fluid speed and pressure in a streamlined flow?

The Bernoulli principle states that in a streamline flow of an incompressible fluid, an increase in the fluid's speed occurs simultaneously with a decrease in pressure or potential energy. This relationship is fundamental in understanding how air flows around an airfoil and is crucial for explaining lift generation.

When air flows over the wing of an aircraft, the shape of the wing causes the air on top to travel faster than the air underneath. According to Bernoulli's principle, as the speed of the air increases over the top surface, the pressure drops. This drop in pressure on top of the wing creates a pressure differential between the upper and lower surfaces of the wing, resulting in lift.

Therefore, when fluid speed increases, pressure decreases, making the correct answer reflect the relationship described by the Bernoulli equation. This principle is a cornerstone of aerodynamics and practical applications such as aircraft design and performance.