Lecture 4

Question 1

stagnation pressure =

Answer 1

total pressure when C is zero, P +0.5densityC^2 = total pressure

Question 2

types of instruments for measuring velocity and flow rate

Answer 2

pitot tube
pitot static tube
oriface plate
venturi meter

Question 3

U tube manometer

Answer 3

change in pressure = P2 - P1

Question 4

U tube manometer equation

Answer 4

see powerpoint

Question 5

adv of utube manometer

Answer 5

reliable (gravity doesnt change much)

accurate

Question 6

disadv of utubue manometer

Answer 6

difficult to setup
no electronic readout
mercury used is toxic
needs to be level (liquid cant slosh around)
slow

Question 7

use of utube manometers

Answer 7

calibrating other pressure gauges

Question 8

pitot tube diagram

Answer 8

see powerpoint

Question 9

change in pressure =

Answer 9

(density of liquid - density of fluid) * g * height difference

Question 10

pitot static tube adv

Answer 10

can be made small

cheap robusy simple accurate close to point measurement

Question 11

disadv of pitot static tube

Answer 11

slow response

must point directly into flow

Question 12

venturi meter actual volume flow rate

Answer 12

discharge coefficient * ideal volume flow rate

Question 13

what is beta for a venturi meter

Answer 13

D/d

Question 14

venturi meter equation

Answer 14

see powerpoint

Question 15

discharge coefficent =

Answer 15

actual velocity/ideal velocity

Question 16

pressure recovery diagram

Answer 16

see powerpoint

Question 17

beta for oriface plate

Answer 17

d/D

Question 18

what is epsilon in the orifice plate equation

Answer 18

expansibility factor 1 for incompressible fluids

Question 19

how to solve oriface plate equation and why

Answer 19

iterative approach as reynolds number is in the equation for discharge coefficient

Question 20

why is the discharge coefficient lower for oriface plates than venturi meters

Answer 20

due to greater number of eddies in the expansion and the reduction

Question 21

p terms for a tank or reservoir equal to

Answer 21

pressure above fluid - if open tank then it is atmospheric if closed tank = pressure above tank

Question 22

discharge velocity from a nozzle pressure =

Answer 22

atmospheric pressure