According to Bernoulli's Principle, what happens when fluid flows through a narrowing tube?

When fluid flows through a narrowing tube, Bernoulli's Principle states that as the cross-sectional area of the flow decreases, the speed of the fluid increases. This principle derives from the conservation of energy in fluid dynamics, indicating that when the fluid's velocity increases because of reduced area, the pressure must decrease correspondingly to maintain the overall energy balance within the system.

This relationship can be understood in practical terms: as the fluid enters a section of the tube with a smaller diameter, it has to flow faster to conserve mass flow rate (mass flow rate is the product of the fluid density, cross-sectional area, and velocity). The increase in velocity results in a drop in static pressure. This is often observed in real-world applications, such as in the design of venturi tubes or aerodynamic shapes where fluid speeds up in constricted areas.

Other options suggest different outcomes, such as an increase in pressure or unchanged fluid behavior, which do not align with Bernoulli's Principle. The correct interpretation emphasizes the interaction between speed and pressure, fundamental to understanding fluid dynamics in aviation and other engineering fields.