1 Using Newtons Second Law as a starting point explain how y

1. Using Newton’s Second Law as a starting point, explain how you would create a flowmeter based on a converging section of pipe for a real (non-ideal) fluid. Your answer must explain
(i) how the degradation of energy is minimised and why this is important
(ii) how you would estimate the volumetric flowrate based on measurements of differential pressure.

Solution

i) degadation of energy occurs due to friction, so minimise friction caused by roughness, cavitation and eddies (turbulence). maintain laminar flow

ii) converging section means velocity increases-- you have accleration. By newton a force is expereicned due to pressure difference.

To measure the pressure diff, then extrapolate the velocity difference. using the energy eqn

DP = rho*(V₁²-V₂²)/(2 g)

where rho =density, g = gravitation const , DP pressure diff in N/m²   , rho =density (N/m³ )

Knowing V at any down stream point where cross sectional area is known , Q= flow rate =V*A