ht

Question 1

is the process where
thermal energy moves from a hotter
body to a colder one.

Answer 1

Heat transfer

Question 2

is a heat transfer that resulted
from macroscopic motion of a body such
as currents in a fluid or fluid flow

Answer 2

Heat Convection

Question 2

Heat is transferred through
molecule to molecule.
* Medium can be solid, liquid,
gas.

Answer 2

Heat Conduction

Question 2

Thermal energy moves through a solid
material (or a stationary fluid) from a
region of higher temperature to a region of
lower temperature1 due tomolecular
interaction and vibration.

Answer 2

Heat Conduction

Question 3

occurs when the heat is
transferred through electromagnetic
waves

Answer 3

Thermal Radiation

Question 4

Heat is transferred through
electro-magnetic waves.
* Surfaces only, no medium
required.

Answer 4

Thermal Radiation

Question 5

Heat is transferred to fluid
flow.
* Medium is fluid (liquid and
gas).

Answer 5

Heat Convection

Question 6

Insulated container/ drinking
bottle
* Rice cooker
* Glue gun

Answer 6

Heat Conduction

Question 7

Electric fan
* Blower
* Steam engine

Answer 7

Heat Convection

Question 8

Incubator
* Solar panel
* Laser engraver/ cutter

Answer 8

Thermal Radiation

Question 9

is the ability of any material to transfer heat

Answer 9

THERMAL
CONDUICTIVITY

Question 10

function of
transferring heat from one fluid to another

Answer 10

Heat exchangers

Question 11

will
typically be either counterflow or
parallel flow.

Answer 11

double pipe heat exchanger

Question 12

are flow-directing or
obstructing vanes or panels used in
some industrial process vessels
(tanks), such as shell and tube heat
exchangers, chemical reactors, and
static mixers.

Answer 12

Baffles

Question 13

utilize heat convection where the
liquid, mainly water which is
evaporated to cool the system.

Answer 13

Evaporation type heat exchanger

Question 14

as the transfer of energy from
the more energetic to the less energetic particles of a
substance due to interactions between the particles

Answer 14

heatconduction

Question 15

are objects in which one
or more layer is composed of different
component.

Answer 15

Composite materials

Question 16

is a composite material in which the
different layers are distributed throughout it
thickness or sandwiched together

Answer 16

Material in Series

Question 17

is a composite material in
which the different layers are distributed
throughout its length.

Answer 17

Material in Parallel

Question 18

represent the fictitious film due to convection and
can be solved as composite material (e.g., plane wall
in series)

Answer 18

The h and h , the convective heat transfer coefficient,

Question 19

s caused by the
existence of a temperature difference due to
imperfections in the touching surfaces.

Answer 19

Thermal contact resistance

Question 20

is the transfer of heat between an
object and a fluid (liquid or gas)
through the actual movement of the fluid. Heat is first transferred at the surface by conduction, but most of the
energy transfer happens because the fluid moves and carries the heat with it.

Answer 20

Convection

Question 21

can occur naturally due
to buoyancy effects caused by temperature
differences, or it can be forced when the fluid is moved using
devices like fans or pumps, or when the object moves through the fluid.

Answer 21

Convection

Question 22

states that, the rate of heat loss of a body is directly proportional to the difference in the temperatures between the body and its surroundings provided the temperature difference

Answer 22

Newton’s law of cooling

Question 23

is a number with no physical units. It is formed from ratios or products of physical properties and is used to simplify and compare complex physical systems, such as fluid flow and heat transfer. Common examples include the Reynolds, Prandtl, Grashof, Nusselt, and Rayleigh numbers.

Answer 23

Dimensionless quantity

Question 24

represents the ratio of inertial forces to viscous forces in a fluid flow and is used to determine whether the flow is laminar or turbulent.

Answer 24

Reynolds Number

Question 25

is the ratio of kinematic viscosity (ν) to thermal diffusivity (α). It indicates the relative effectiveness of momentum diffusion compared to heat diffusion within the velocity and thermal boundary layers.

Answer 25

Prandtl Number (Pr)

Question 26

is the ratio of a buoyancy force times an inertial force to the square of a viscous force and is used in analyzing the velocity distribution in free convection system

Answer 26

Grashof Number (Gr)

Question 27

is the ratio of heat transfer by convection to heat transfer by conduction. It shows how effective convection is at transferring heat at a surface—higher Nu means better convection heat transfer.

Answer 27

Nusselt Number (Nu)

Question 29

characterizes natural (free) convection flow and is the product of the Grashof and Prandtl numbers, combining the effects of buoyancy, viscosity, and thermal diffusion.

Answer 29

Rayleigh Number (Ra)