Question

Hey guies can u please help me with this Bernoulli’s theorem. im not understanding it even a bit!!!!!!!

Answer 1

Are you referring to Bernoulli's law for fluid flow?

Answer 2

yes! please!

Answer 3

Consider the following diagram of a non viscous, non compressible fluid with a density rho flowing in a pipe of varying diameter at different heights between arbitrary points A and B Where PA is the pressure of the fluid a pt A and PB the pressure at B. VA it the velocity of the fluid at A and VB at B. HA is the height of the pipe some arbitrary surface and HB the height above that same surface at B. OK so far?
Bernoulli's Law state that the sum of the pressure, kinetic energy per unit volume and the potential energy per unit vol of the fluid at A is the same as at B. \[P _{A}+\rho v _{A} ^{2}/2 +\rho gH _{A} =P _{B}+\rho v _{B} ^{2}/2 +\rho gH _{B} \] g is the acceleration due to gravity. Verify that the units of the terms in the equation are the same.
Normally you don't have the velocity but it can be found in terms of the flow. Flow is volume/unit time as liters/sec. Flow = area of the pipe x the velocity. So if the velocity is not given you need the flow and the area of the pipe at that point. Make sure your units are consistent.
meters, seconds, Kg/m^3, Nt/m^2
or
ft, seconds, slugs/ft^3, lbs/ft^2

The pressure in the pipe can be applied by a pump where it might be referred to a gauge pressure or it might be caused by a column of the fluid rising above the point coming from the weigh of the fluid above that point. That pressure then would be\[Pressure at bottom of a column of fluid = density*g*height of the fluid \above point\]

Questions?