Practice Question 1
1. Figure 1 shows a level control system. The valve is open when the relay is closed and vice
versa. The relay closes at 4 V and opens at 5 V. The level sensor has a transfer function of Vh
= 1.2h + 0.8 V.
(i) Find the value of amplifi

Chapter 11
Heat Exchangers (11.1-11.3)
Heat Exchangers
Dr TangSY
1
1
Heat Exchangers
A heat exchanger is used to exchange heat between two fluids of
different temperatures, which are separated by a solid wall.
Heat exchangers are ubiquitous to energy co

Chapter 14
Mass Transfer by Diffusion
Mass Transfer
Dr. TangSY
1
1
Learning Outcomes
Understand the concentration gradient and the physical
mechanism of mass transfer
Recognise the analogy between heat and mass transfer
Describe the concentration at a

4/2/2014
Pre-requisite:
UEME 2123 Fluid Mechanics I
Course Syllabus
Convener: Dr Tang Siah Ying @ Dr Patrick Tang
Email: [email protected]
Office: 4th Floor West Wing
Tutor: Ms Tan Yin Qing
Email: [email protected]
Lab instructor: Ms Tan Lee Fan, Email:

Chapter 1: Introduction to Heat Transfer
1. A concrete wall, which has a surface area of 20 m 2 and is 0.30 m thick, separated conditioned
room air from ambient air. The temperature of the inner surface of the wall is maintained at 25 0C,
and the thermal

Extended Surfaces (Fins)
An extended surface (also known as a combined conduction-convection
system or a fin) is a solid within which heat transfer by conduction is
assumed to be one dimensional, while heat is also transferred by convection
(and/or radiat

Extended Surfaces / Fins
Sections 3.6, 11.2
Chapter 3
Dr. TangSY
1
Extended Surfaces (Fins)
An extended surface (also known as a combined conduction-convection
system or a fin) is a solid within which heat transfer by conduction is
assumed to be one dimen

CHAPTER 3 : HEAT EXCHANGERS
Example Problems:
Q1
Cold water (cp = 4.18 =J/kgC) enters a cross-flow heat exchanger at 14C at a rate of 0.35
kg/s where it is heated by hot air (cp = 1.0 kJ/kgC) that enters the heat exchanger at 65C at
a rate of 0.8 kg/s and

Tutorial 5
Internal forced convection
1. A flat-plate solar collector is used to heat atmospheric air flowing through a rectangular channel. The
bottom surface of the channel is well insulated, while the top surface is subjected to a uniform heat
flux, wh

Tutorial 4
Chapter 7: External forced convection
1. Air at a pressure of 6 kN/m2 and a temperature of 300oC flows with a velocity of 10 m/s over a flat
plate, 0.5 m long. Estimate the cooling rate per unit width of the plate needed to maintain it at a
sur

Chapter 12: Radiations
1. Consider a 20 cm diameter spherical ball at 800 K suspended in air as shown in Fig 12-12.
Assuming the ball closely approximates a blackbody; determine (a) the total blackbody
emissive power, (b) the total amount of radiation emi

Tutorial 3
1.
2.
1
3.
4.
2
5.
6. Turbine blades mounted to a rotating disc in a gas turbine engine are exposed to a gas stream that is at
T = 12000C and maintains a convection coefficient of h = 250 W/m2.K over the blade.
The blades, which are fabricated

Faculty of Engineering and Science (FES)
Department of Chemical Engineering
Laboratory Report
Writing and Format
Table of Content
1.0
ASSESSMENT OF LABORATORY REPORT.2
2.0
LABORATORY REPORT WRITING.2
2.1
Content .3
2.2
English language use .4
2.3
Report S

Practice Question 3
1. The speed of a motor is controlled using an integral mode controller the output of which is
given by
, where KI is the controller gain, ep the error and p(0) the
t
p (t ) K I p dt p (0)
e
0
initial controller output. The controller

Practice Question 5
1. A 8-bit DAC with a 10.0 V reference is connected to a heater. Calculate the heater
temperature if the input of the DAC is 10110111 2. The temperature of the heater can be
determined as follow:
T = 11V(3/2) (C)
(Ans: T = 210.237 C)
2

Practice Question 7
1. A proportional mode control system is implemented to control the condenser fan speed of a
refrigerator by using temperature measurement. Develop the control equations according to
the specifications as shown below:
(i)
(ii)
(iii)
(i

Practice Question 6
1. Figure 1 shows a system that is proposed to turn on an alarm system when the output
voltage of the differential amplifier is 1.1 V. An RTD with o = 0.005/C and Ro = 160 at 40
C is used in the bridge circuit. Determine the RTD temper

Practice Question 2
1. Design the physical and programmed ladder diagram for controlling a motor with the
following condition:
- NO start button
- NC stop button
- thermal overload limit switch opens on high temperature
- green light turn on when running

Quiz 1
A current balance bridge shown in Figure 1 has resistance of R1 = 1 k, R3 = 600 , R4 = 590 , R5 = 10 , R6 =
1 k, R7 = 10 k and V = 10 V.
(i) Determine the value of R2 that nulls the bridge with a current, I = 40 mA.
(4 marks)
(ii) Determine the val

Quiz 2
Figure 1 shows a measurement of temperature using sensor that outputs 4.0 mV/C. A n-bit, unipolar ADC with a
reference of 10 V is used.
(a) Determine the number of bits necessary for the ADC if a temperature resolution of 0.1 C is required.
(4 mark

Practice Question 4
1. Figure 1 shows a fan control system. Design a two-position controller to turn a fan ON if
the temperature is 70 C and OFF when below 40 C. The resolution of the temperature sensor
is given as 15 mV/ C. Determine the values of the re

UNIVERSITI TUNKU ABDUL RAHMAN
UEME3213 HEAT AND MASS TRANSFER
Group Assignment
Name
ID
Course
Robin Chew Yon Fei
Wong Zhen Yan
Tan Sheau Yuan
Lee Chee Heng
Tan Meng Hui
1201804
1201657
1205597
1201606
1203144
ME
ME
ME
ME
ME
Question 1 (a)
The figure above

Heat Transfer Correlations for Internal Flow
Knowledge of heat transfer coefficient is needed for calculations
shown in previous slides.
Correlations exist for various problems involving internal flow,
which includes laminar flow in circular.
For lamina

Chapter 6 (6.1-6.4, 6.5.2)
Introduction to Convection/Heat
transfer coefficients
Introduction to Convection
Dr TangSY
6-1
1
Introduction to Convection
Convection denotes energy transfer between a surface and a fluid
moving over the surface.
The dominant