Chapter 1

Question 1

What is heat transfer?

Answer 1

Thermal Energy transit due to spatial temperature difference

Question 2

What is Conduction?

Answer 2

Heat transfer were the temperature gradient exists in a stationary medium, solid or liquid, aka conduction oven.

Question 3

What is Convection?

Answer 3

Heat transfer that occurs between a surface and a moving fluid when they are at different temperatures. Aka convection oven.

Question 4

What is Temperature Gradient?

Answer 4

A temperature gradient is the physical quantity that describes which direction and at what rate the temperature changes most rapidly around a particular location.

Question 5

What is Thermal Radiation?

Answer 5

Heat transfer between two surfaces at different temperature.

Question 6

What is the driving force behind conduction?

Answer 6

The driving force behind conduction is atomic and molecular activity. Conduction is the transfer of energy from more energetic to less energetic particles.

Question 7

Whats is diffusion?

Answer 7

Spreading of something more widely, going to equilibrium all over.

Question 8

What is heat flux (conduction) and units and symbol?

Answer 8

Rate of heat transfer per unit area and W/m^2 and qx’’.

Question 9

What is heat rate by conduction and symbol and units?

Answer 9

Heat rate is the heat flux multiplied by the area and qx and watts.

Question 10

What are the two mechanisms convection is comprised of.

Answer 10

Diffusion (random molecular motion), or by bulk or macroscopic motion of fluid.

Question 11

What is Sensible energy?

Answer 11

Sensible energy is energy that can be felt like change in temperature.

Question 12

What is Latent Energy?

Answer 12

Latent energy is related to phase change.

Question 13

How is energy of radiation transported?

Answer 13

Electromagnetic Waves.

Question 14

What is surface emissive power? units symbol

Answer 14

Rate at which bounded energy is released. W/m^2 E

Question 15

What is emissivity? Symbol?

Answer 15

A measure of how efficiently a surface emits energy relative to a blackbody. Epsilon

Question 16

What is absorptivity? Symbol?

Answer 16

The rate at which radiant energy is absorbed per unit surface area. α

Question 17

E or EB

Answer 17

Surface emissive power or Surface emissive power of a black body

Question 18

q’’

Answer 18

heat flux, rate of heat transfer per unit area

Question 19

G

Answer 19

irradiation-incoming radiation

Question 20

sigma

Answer 20

stephan boltzman constant

Question 21

Rt

Answer 21

Thermal Resistance

Question 22

1st Law Thermo

Answer 22

The first law of thermodynamics states that energy can neither be created nor destroyed; it can changed only from one form to another

Question 23

2nd Law Thermo

Answer 23

The second law of thermodynamics means hot things always cool unless you do something to stop them.

Question 24

Two ways energy can cross system boundry in a closed system.

Answer 24

Heat and Work done to or by the system.

Question 25

Closed System

Answer 25

System that doesn’t allow for transfer of mass in or out of the system.

Question 26

Control Volume

Answer 26

an imaginary surface enclosing a volume of interest.

Question 27

Mechanical Energy

Answer 27

sum of kinetic Energy and potential energy

Question 28

Kinetic Energy equation

Answer 28

1/2*mV^2

Question 29

potential energy

Answer 29

mgh

Question 30

Thermal energy consists of

Answer 30

latent and sensible

Question 31

Ut

Answer 31

Thermal Energy/ unit mass

Question 32

row v

Answer 32

flow work

Question 33

q

Answer 33

heat rate transfer W

Question 34

Heat Engine

Answer 34

any device that operates continuously or cyclically and converts heat to work.

Question 35

Carnot Efficeincy

Answer 35

High real possible efficiency of a heat motor

Question 36

Entropy

Answer 36

the measure of a system’s thermal energy per unit temperature that is unavailable for doing useful work.

Question 37

Enthalpy

Answer 37

l

Question 38

Q

Answer 38

Energy Transfer

Question 39

the rate at which heat passes through a specified material, W/m^s

Answer 39

Thermal Conductivity

Question 40

Thermal Conductivity units and symbol

Answer 40

the rate at which heat passes through a specified material, W/m^s and k

Question 41

Thermal Energy

Answer 41

Movement of atoms and molecules, linked directly to temperature of matter.

Question 42

Joule Units

Answer 42

W*s

Question 43

Watt

Answer 43

Joule/Sec

Question 44

Work

Answer 44

Force*Distance

Question 45

Fouriers Law

Answer 45

heat flux qx’’=-k*dT/dX

Question 46

hr meaning and units

Answer 46

Radiation Heat Transfer Coefficient W/m^2*K

Question 47

h

Answer 47

convection heat transfer coefficient W/m^2*K

Question 48

What are the units for energy?

Answer 48

Joules

Question 49

What is a joule? Units?

Answer 49

Energy and Watts*second

Question 50

What is a watt and units

Answer 50

Power rate of energy transfer and Joules/Sec

Question 51

Steady State

Answer 51

No change of parameters with respect to time

Question 52

Driving Force behind convection and conduction

Answer 52

Temperature Difference

Question 53

Rate Equation for Convection

Answer 53

h A(T final- T surface)

Question 54

Newtons Law of Cooling

Answer 54

q’‘=h(T surface-T infinity)

Question 55

Stefan Boltzmann Law and meaning

Answer 55

Eb=Sigma Tsurface^4 Upper limit of emissive power

Question 56

Gabs equation

Answer 56

G* alpha

Question 57

alpha

Answer 57

absorptivity

Question 58

specific heat

Answer 58

amount of heat required to raise 1 kg of material one degree Kelivn. J/kg*K

Question 59

Specific volume

Answer 59

1/density