fluid dynamics
DESCRIPTION
FLUID DYNAMICS. BERNOULLI’S EQUATION BY GP CAPT NC CHATTOPADHYAY. Daniel Bernoulli. - PowerPoint PPT PresentationTRANSCRIPT
FLUID DYNAMICS
BERNOULLI’S EQUATION
BY GP CAPT NC CHATTOPADHYAY
Daniel Bernoulli
(Groningen, 8 February 1700 – Basel, 8 March 1782) was a Dutch-Swiss mathematician and was one of the many prominent mathematicians in the Bernoulli family. He is particularly remembered for his applications of mathematics to mechanics, especially fluid mechanics, and for his pioneering work in probability and statistics. Bernoulli's work is still studied at length by many schools of science throughout the world.
INTRODUCTION
•A statement of the conservation of energy in a form useful for solving problems involving fluids.
• For a non-viscous, incompressible fluid in steady flow, the sum of pressure, potential and kinetic energies per unit volume is constant at any point
•A special form of the Euler’s equation derived along a fluid flow streamline is often called the Bernoulli Equation
AVAILABLE ENERGY HEADS
1. 1. PR HEAD:: DUE TO PR OF LIQUID = p/w
2. 2. PE HEAD: DUE TO POSITION OF FLUID LEVEL = z
3. 3. VELOCITY HEAD: DUE TO VELOCITY i.e KINETIC ENERGY
HEAD = v2/2g
STATEMENT
FOR A STEADY,STREAMLINE FLOW OF AN IDEAL, INCOMRESSIBLE FLUID, THE SUM OF KINETIC, POTENTIAL AND PR ENERGY IS CONSTANT
EXPLAINATION
1,A1,v1,
p1,z1
SECTION-1
SECTION-2
2,A2,v2
p2,z2
p1 /w + v12/2g + z1 = p2/w + v2
2/2g +z2
FLOW
DERIVATION
AS DERIVED IN THE CLASS
ALSO, PL REFER TO RECOMMENDED TEXT BOOKS
NUMERICALS
1. DIA OF A PIPE CHANGES FROM 200mm AT A SECTION 5m ABOVE DATUM TO 50mM AT A SECTION 3m ABOVE DATUM. PRESSURE OF WATER IS 500kPa AT INLET WITH A VELOCITY 1m/s. DETERMINE PR AND VELOCITY AT EXIT.
2. BRINE OF S.G 1.15 IS DRAINING FROM BOTTOM OF A LARGE OPEN TANK. THE DRAIN PIPE ENDS 10 m BELOW THE FREE SURFACE. CONSIDERING THE FLOW AS STEADY AND ALONG STREAMLINE CALCULATE THE DISCHARGE VELOCITY. (NEGLECT FRICTION)
ASSIGNMENT
1. PRACTISE DERIVATION OF BERNOULLI’S EQUATION
2. SOLVE. A 5m LONG PIPE IS INCLINED AT 150 TO THE
HORIZONTAL. SMALLER END OF PIPE IS AT LOWER LEVEL AND IS OF 80mm DIA WHILE THE LARGER SECTION IS OF 240mm DIA. IF THE INLET VELOCITY IS 1m/S, FIND EXIT VELOCITY AND PR DIFFERENCE BETWEEN TWO SECTIONS
EULER’S EQUATION OF MOTION
AS DERIVED ON THE BOARD
BERNOULLI’S EQUATION WILL BE ESTABLISHED FROM ABOVE
ASSUMPTIONS
FLOW IS STEADY FLOW IS INCOMPRESSIBLE FLOW IS ALONG STREAMLINE (1 D) FLOW IS INVISID NO HEAT OR WORK TRANSFER NO ENERGY LOSS TO ENVIRONMENT VELOCITY IS UNIFORM (Um) ONLY FORCES ARE DUE TO PR AND GRAVITY
LIMITATIONS
VELOCITY MAY NOT BE UNIFORM IN A REAL FLOW
VISCOUS AND FRICTIONAL FORCES EXIST IN A REAL FLOW
CENTRIFUGAL FORCE MAY ALSO BE PRESENT IN A FLOW THROUGH CURVED PATH
HEAT TRANSFER ALSO OCURS DUE TO CONVERSION OF KINETIC ENERGY INTO HEAT
Application of Bernoulli’s Principle
MAJOR APPLICATIONS
MEASUREMENT OF FLOW VELOCITY
MEASUREMENT OF FLOW DISCHARGE
PITOT TUBE (WITH AOAI)
PITOT TUBE
Stagnation pressure = static pressure + dynamic pressure
Which can also be written
Solving that for velocity we get:
USE OF PITOT SYSTEM
PITOT STATIC SYSTEM
DISCHARGE MEASUREMENT
VENTURIMETER
ORIFICEMETER
ROTAMETER
VENTURIMETERA venturi can be used to measure the volumetric flow rate Q.Since
then
ORIFICE METER
ROTAMETER
A rotameter is a device that measures the flow rate of liquid or gas in a closed tube.It belongs to a class of meters called variable area meters, which measure flow rate by allowing the cross-sectional area the fluid travels through to vary, causing some measurable effect.
SO,WHAT DO U DO ?
CONCENTRATE ON THE BOARD FOR THE DERIVATION
GO THROUGH THE TOPIC COVERED SO FAR AND ……
HAVE PATIENCE TILL NEXT FM CLASS ON THE BOARD PL…..
TIME TO ENJOY…….
EID MUBARK….
SEE U ALL ON THE FIRST DAY… FIRST SHOW…. AFTER BREAK…..