- #1
Famwoor2
- 11
- 1
Hello there; I am having a conceptual problem with the hydraulic analogy (a collection of similarities between electrical circuits and piping systems). It specifically has to do with the topic of pressure and voltage drops.
The hydraulic analogy claims that pressure drops act like voltage drops, and that constrictions to flow act like resistors. I know from basic circuit analysis that there is a potential drop across a resistor (Ohm's law). By the hydraulic analogy, there should be a pressure drop across a constriction in the bore of a pipe. However, Bernoulli's equation says that (in a closed loop piping system) once the bore of the pipe returns to its pre-constriction magnitude, the pressure in the pipe returns to its former value as well. This implies that there is actually no pressure drop across the constriction, directly contradicting the hydraulic analogy. I am sure that there is a clear error in my logic; please help me find it!
Thanks for your help and time,
F2
The hydraulic analogy claims that pressure drops act like voltage drops, and that constrictions to flow act like resistors. I know from basic circuit analysis that there is a potential drop across a resistor (Ohm's law). By the hydraulic analogy, there should be a pressure drop across a constriction in the bore of a pipe. However, Bernoulli's equation says that (in a closed loop piping system) once the bore of the pipe returns to its pre-constriction magnitude, the pressure in the pipe returns to its former value as well. This implies that there is actually no pressure drop across the constriction, directly contradicting the hydraulic analogy. I am sure that there is a clear error in my logic; please help me find it!
Thanks for your help and time,
F2