Venturimeter,orificemter and pitot tube

This presentation will clear the idea of Venturi meter orifice meter and pitot tube.

1. Aldel Education Trust’s ST. JOHN COLLEGE OF ENGINEERING AND MANAGEMENT, PALGHAR (ST. JOHN POLYTECHNIC) D EPARTMENT OF MECHANICAL ENGINEERING S UB: FLUID MECHANICS AND MACHINERY T OPIC: VENTURIMETER, ORIFICEMETER & PITOT TUBE PREPARED BY:- Prof. Pranit Mehata Lecturer, SJCEM 7972064172

2. VENTURIMETER A venturimeter is one of the most important practical applications of Bernoulli’s theorem. It is an instrument used to measure the rate of discharge in a pipeline F ixed permanently at different sections of the pipeline to know the discharges there. A venturimeter has been named after the 18th century Italian engineer Venturi

3. VENTURIMETER Venturimeter may be classified as follows: 1. Horizontal venturi meters. 2. Vertical venturi meters. 3. Inclined venturi meters. A venturimeter consists of the following three parts: A short converging part, Throat, and Diverging part.

4. VENTURIMETER Discharge through the venturimeter is given by Actual discharge is given by , =coefficient of discharge. Its value for venturi meter is 0.98  

5. ORIFICEMETER Orifice meter or orifice plate is a device employed for measuring the discharge of fluid through a pipe. It also works on the same principle of a venturimeter . It is cheaper than venturimeter. It consists of a flat circular plate having a circular sharp edged hole (called orifice) concentric with the pipe. The diameter of the orifice may vary from 0.4 to 0.8 times the diameter of the pipe but its value is generally chosen as 0.5. Section 2-2 is called as Vena-contracta. At this section area of fluid is minimum, whereas velocity is maximum and pressure is minimum. Maximum pressure drop will occur at vena-contracta.

6. ORIFICEMETER Discharge through the orifice meter is given by Actual discharge is given by , =coefficient of discharge. Its value for orifice meter is 0.64  

7. PITOT TUBE A pitot tube is the simple device used for measuring the velocity of the flow at the required point in a pipe or a stream. It is also called as impact tube or stagnation tube. It is based on the principle that if the velocity of flow at a point becomes zero, the pressure is increased due to conversion of kinetic energy into pressure energy

8. PITOT TUBE Velocity of fluid through the pitot tube is given by Actual velocity is given by , =coefficient of velocity. Its value varies from 0.95 to 1.  

9. HYDARULIC COEFFIECIENTS Coefficient of Discharge ( ): The ratio of actual discharge to the theoretical discharge. Coefficient of Contraction ( ): The ratio of area of vena contracta to the area of the orifice. Coefficient of Velocity ( The ratio of the actual velocity of fluid to the theoretical velocity.