Item no.: F14

Introduction

it is generally designed as a venturi meter to measure the flow rate or flow velocity, includes liquid or gas, inside the piping system of varying cross-section. Base on the conservation of flow as well as mechanical energy (Bernoulli equation), i.e. V(flow velocity) x A( cross-section area) =constant and P (hydraulic static pressure)/ρg + V2 /2g =constant, the fluid flowing through pipe-throat will have the maximum local speed and minimum hydraulic pressure which will induce the rise of water. While refer to the elevation of liquid, the fluid velocity flowing along the center line of piping system might be successfully.

Objectives

1. Measure flow rate by timing the water collection.
2. Measure flow rate by flow meter of float-sink.
3. Measure flow rate by dynamical tube.
4. Measure flow rate by venturi tube.

Experiment —Venturi Tube

The magnitude of static pressure, dynamical pressure as well as estimated flow velocity might be easily accessed from the profile of liquid elevated at each tube, which is mounted at different scale of diameter along the pipe and used to confirm the validity of Bernoulli equation. Coupling with volumetric flow continuity and Bernoulli equation in Eqs.(1) ~Eqs.(2), flow velocity traveling through venturi-pipe of variable diameters will be developed in Eqs.(3).That also means local flow velocity might be expressed in terms of liquid elevation indicating the static pressure induced.