16.4 : 静压、滞压、动压和总压

Bernoulli's principle states that the total pressure remains constant along a streamline in a fluid system and is the sum of static, dynamic, and potential energy pressures.

Static pressure is the force exerted by a fluid at rest, commonly observed in pipelines and water supply systems.

It depends on the fluid's height and density and acts perpendicular to the surface in contact with the fluid.

Dynamic pressure is related to the fluid's velocity and represents the energy due to motion.

It is crucial in designing systems involving fast-moving fluids, such as stormwater drainage or high-velocity river channels.

Stagnation pressure occurs when the fluid is brought to rest, combining static and dynamic pressures.

It is measured at stagnation points, like dam surfaces or turbine blades, where the fluid's velocity is reduced to zero.

Understanding the balance of static, dynamic, and stagnation pressures helps manage pressure changes and energy in fluid systems.

These pressures are measured using devices like Pitot-static tubes, critical for airspeed and fluid flow calculations in various civil engineering applications.