Bernoulli principle
Narrow the pipe and see the flow speed rise as the pressure drops.
In the steady flow of an incompressible fluid, the same volume passes through every cross-section per unit time. Narrowing a horizontal pipe increases the flow speed and lowers the static pressure; widening it has the opposite effect.
Pressure difference vs. outlet area
Positive values mean the inlet static pressure is higher than at the outlet; inlet conditions stay at the current settings.
Think about it
With the inlet conditions unchanged, how does the outlet speed change if the outlet cross-sectional area is halved?
The outlet speed increases to 2 times its original value. The continuity equation requires A₂v₂ to stay constant.
Model assumptionsIdeal incompressible water · Steady flow · Horizontal pipe · ρ = 1000 kg/m³ · Viscosity and friction losses neglected
Data log
Set the parameters and click “Record data”. Record several rows with different parameters to plot their relationship and fit a straight line; pause and record at different times to study how a reading changes with time.