Thermofluids L1

Question 1

What are FLUID MECHANICS?

Answer 1

The branch of physics that studies the mechanics of fluids (liquids, gases and plasma) and the forces on them.

Question 2

What is a FLUID?

Answer 2

• A fluid is a substance that continually deforms (flows) under an applied shear stress
• It has no fixed shape and yields to
  pressure

Question 3

What can fluids include?

Answer 3

liquids, gases, plasmas and, to some extent, plastic solids

Question 4

What is Relative Density?

Answer 4

The ratio of the density of a substance to the density of a given reference material

Question 5

What is a Specific Volume?

Answer 5

The specific volume of a substance is the ratio of the substance’s volume to its mass.
It is the reciprocal of density and an intrinsic property of matter as well

Question 6

Why is volume is an extensive property?

Answer 6

Volume is an extensive property as it is dependent upon the size of a
system

Question 7

Why is Specific volume is an intensive property?

Answer 7

Classed as an intensive property as it is independent of system size

Question 8

What is the equation for Specific Volume?

Answer 8

V = v / m = 1 / p

Question 9

What is Pressure (Pa)?

Answer 9

The force applied perpendicular to the surface of an object per unit area over which that force is distributed

Question 10

What is absolute pressure?

Answer 10

• The pressure of having no matter inside a space, or a perfect vacuum.
• Measurements taken in absolute pressure use this absolute zero as their reference point

Question 11

What is Gauge pressure?

Answer 11

• Gauge pressure is measured in relation to ambient atmospheric pressure
• A gauge pressure higher than ambient pressure is referred to as positive pressure
• If the measured pressure is below atmospheric pressure it is called negative or vacuum gauge pressure

Question 12

What is the difference between Gauge and Absolute Pressure?

Answer 12

• Absolute pressure uses absolute zero as its zero point, while gauge pressure uses atmospheric pressure as its zero point
• Due to varying atmospheric pressure, gauge pressure measurement is not precise, while absolute pressure is always definite

Question 13

What is the equation for Pressure above P(atm)?

Answer 13

P(gauge) = P(abs) - P(atm)

Question 14

What is the equation for Pressure below P(atm)?

Answer 14

P(vac) = P(atm) - P(abs)

Question 15

What is the relationship between Pressure and Depth?

Answer 15

As the Depth increases the Pressure increases as fluid layers rest on other fluid layers