Final answer:
Open channels refer to cases where water is not pressurized and flows due to gravity in a channel that is not fully enclosed. The flow and pressure of fluids in these channels are influenced by gravity and channel geometry, as well as principles such as Bernoulli's principle that affects fluid speed and pressure.
Step-by-step explanation:
Open channels refer to Cases in which water is not pressurized, and is conveyed by gravity in open channels. This concept is an essential part of fluid dynamics and water engineering. The pressure in an open channel does not influence the flow in the same manner as it does in a closed system. Instead, the water is subject to gravity and the channel's shape and slope. This differs from closed systems, where water can be pressurized and the flow controlled by mechanical means.
The behavior of fluids is also influenced by concepts such as Bernoulli's principle, which explains how pressure in a fluid decreases as the fluid's velocity increases. This principle is observable in both open and closed fluid systems, affecting the speed and pressure of the fluid within. Understanding how pressure, area, and force interrelate is critical in engineering applications, from designing channels to developing systems that exploit these principles, such as aspirators and carburetors.