INSTRUMENTATION AND CONTROL ME-2113

1. INSTRUMENTATION AND CONTROLME-2113 Instructor: Engr. Hassaan Bin Younis

2. FLOW Definition: To move with a continual change of place among the constituent particles  OR SIMPLY To move in a continuous and smooth way

3. FLOW Types: • Uniform Flow: A flow in which velocities of fluid particles at all sections of the pipe or channel are equal is called uniform flow • Non-Uniform flow: A flow in which velocities of fluid particles at all sections of the pipe or channel are not equal is called non-uniform flow • Sreamline Flow: A flow in which each fluid particle has a definite path and the path of individual particles do not cross each other. It is also called Laminar Flow • Turbulent Flow: A flow in which each fluid particle does not have a definite path and the path of individual particles cross each other.

4. FLOW • Compressible Flow: A flow, in which the volume of a fluid and its density changes during the flow is called compressible flow • Incompressible Flow: A flow, in which the volume of a fluid and its density does not change during the flow is called incompressible flow • Rotational Flow: A flow in which the fluid particles also rotate about its own axes while flowing, is called rotational flow. i.e. It has angular velocity • IrrotationalFlow: A flow in which the fluid particles do not rotate about its own axes while flowing, is called rotational flow. According to axes there are one, two and three dimensional flows

5. BERNOULLI’S EQUATION “For an incompressible fluid, flowing in a continuous stream, the total energy of the particle remains the same, while the particle moves from one place to another”

6. LIMITATIONS OF BERNOULLI’S EQUATION 1) The Velocity of Liquid particle in the centre of a pipe is maximum and gradually decreases towards the walls of the pipe due to friction. So only the Mean Velocity of the Liquid should be taken into account because the Velocity of Liquid particles is not uniform. 2) There are always some external Forces acting on the Liquid, which affects the Flow of Liquid. Ideally it is not considered.3) In Turbulent Flow some Kinetic Energy is converted into Heat Energy and in a Viscous Flow some Energy is lost due to Shear Forces. So all such losses should be neglected. 4) If the Liquid is Flowing through curved path, the energy due to Centrifugal Forces should also be taken into account.

7. REYNOLD’S NUMBER • Re<2300, Flow is laminar • 2300<Re<4000, flow is neither laminar nor turbulent (Transient flow) • Re>4000, flow is turbulent The Reynolds number is defined as the ratio of inertial forces to viscous forces and consequently quantifies the relative importance of these two types of forces for given flow conditions. µ= dynamic viscosity coefficient V= Maximum velocity of the object L= characteristic linear dimension, (travelled length of the fluid)

8. FLOW RATE SENSORS There are four main groups of flow rate sensors to measure the flow rate of a fluid: Mechanical Flow rate sensors Differential Pressure based measurement based flow rate sensors Thermal flow rate sensors Mass flow rate sensors

9. MECHANICAL FLOW METERS

10. MECHANICAL FLOW METERS

11. MECHANICAL FLOW METERS

12. MECHANICAL FLOW METERS

13. MECHANICAL FLOW METERS

14. DIFFERENTIAL PRESSURE FLOW METERS

22. Orifice Plate

26. Venturi Tube

31. Flow Nozzle

33. Flow Rate Sensors Pitot Tube