Qassim University – College of Engineering
GE 213
Introduction to Engineering Design II
Semester 382
(1439, Second semester)
Assignment # 3 On Chapter 4
Assignment #3
By
Group 1
Team 3
Member 1
Member
Name
Department
PIN
1
Yaqoub Alhomidany
ME
361108822
Instructor
Dr. Muneer Saeed
Date: 19 / 3 / 2018
GE 213, Semester 382
Group#1-Team #3- Member#1: Yaqoub
Assignment No. 3 on Chapter 4
1. Introduction
In this course GE213, the use of Excel Software was learned. The Excel software is a useful tool for applying
engineering models. The Excel will help me to solve the problem [1]. It is an individual assignment through which
a simple deterministic model is performed in the Excel workbook.
This is the first individual assignment in this course GE213, which is about Chapter 4 in "how to model it"
book. In this assignment, there will be a list of useful heuristics found in this chapter. Also, it will mention a set
of definitions which are algorithm, heuristic of Gordian knot, lumped parameters, heuristic of salami tactics, event
driven models, and time driven models. The second part of this assignment is about a small shop that sell hot milk
produced by a company and this shop is seeking for an advice to know how much it take to worm the milk if the
shop put it in the stove with a given volume capacity under a given temperature.
In this assignment, it is required to use Goal seek in the Excel work to make the curve touch a specific point
in the graph.
2. External Problem
To solve the external problem, firstly, the problem should be well defined and find if there are any assumptions
are stated. The heuristics can be helpful for solving the problem. The mathematical equations that used in the
calculation are provided. Finally, implementing the assignment by using Excel.
2.1 Problem definition.
1) You are a production engineer working for Almarai company. One of the small shop selling hot milk
producing from Almarai is seeking your advice to know how much time it take to worm the milk if we
put it in the stove with 500 cm3 capacity under the temperature of 60°C (Note that the initial temperature
of the milk is 3°C).
2) The given data:
a) The initial temperature of the milk is 3°C.
b) The final temperature of the milk is 60°C.
c) The stove capacity is 500 cm3
d) At 20°C the density is 998 kg/m3 and the specific heat is 4.182 Kj/kg.°C.
Page 1 of 9
GE 213, Semester 382
Group#1-Team #3- Member#1: Yaqoub
Assignment No. 3 on Chapter 4
2.2 Assumptions
- The time increment is +0.25 min
2.3 Heuristics
- Find the value of 'k' by using graph and Goal Seek.
- Model the problem by using an Excel sheet.
2.4 Modeling Steps and Mathematical Equations
Its giving the equations that were used in Excel which are:
Tt = T0 – K × dt (TF – T0)
(1.1)
Where:
Tt: is the new temperature, ⁰C.
T0: is the initial temperature, = 3 ⁰C.
K: is constant.
dt: is the time, min.
TF: is the final temperature, = 60⁰C
Q = 1000 × 𝝆 × Cp × (T – T0)
(1.2)
Where:
Q: the total rate of heat added to the milk, kW.
𝜌: the density of the milk at 20 ⁰C, = 998 kg/m3.
Cp: the specific heat of the milk at 20 ⁰C, = 4.182 kJ/kg. ⁰C.
T: the specific temperature, = 20 ⁰C.
T0: the initial temperature, = 3 ⁰C.
2.5 Model Implementation
The model implementation is divided into 4 sections: Information area, Data area, Calculation area and the
charts.
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GE 213, Semester 382
Group#1-Team #3- Member#1: Yaqoub
Assignment No. 3 on Chapter 4
2-5-1 Information area
This information about me which include: the team number, semester, group number, assignment number and
so on… as shown in figure (1).
figure (1): Information area of the Excel model
2-5-2 Data area
Data area show the values that are given in the problem as shown in figure (2). These values are obtained from
the assignment sheet [2].
figure (2): Data area of the Excel model
Page 3 of 9
GE 213, Semester 382
Group#1-Team #3- Member#1: Yaqoub
Assignment No. 3 on Chapter 4
2-5-3 Equations of the Excel model
The Excel model formula shows that the mathematical equation that were used to create the Excel model is
shown in figure (3)
figure (3): Equation used in the Excel Model
2-5-4 Overall View of the Excel Model
The overall view of the excel model created to solve the external problem is shown in figure (4).
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GE 213, Semester 382
Group#1-Team #3- Member#1: Yaqoub
Assignment No. 3 on Chapter 4
figure (4): The overall excel model for solving the external problem
2.6 Result and Discussion
This section includes the answers of the constructed model as well as the graphs of external problem.
2-6-1 Answer of Question 1.a
This is a list of some useful heuristics in chapter 4:





Lumping several factors into single parameter.
Present the answer as a trade-off rather than a number.
Deciding to construct the solution one step at a time.
Reducing the problem to its essential elements.
Calibrating the model via information from the “real world”.
2-6-2 Answer of Question 1.b
These are the terminologies that were mentioned in this chapter and its definition:
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GE 213, Semester 382
Group#1-Team #3- Member#1: Yaqoub
Assignment No. 3 on Chapter 4
1) Algorithm: Procedure discretion by terminates with the result [3].
2) The Gordian Knot: The problem looks difficult and complex by the first look. Once you find its weak
point it will become easy [3].
3) Lumped Parameters: instead of use several parameters like thermal properties of beer and glass or
aluminum, introduce only one parameter, for instance the proportionality constant K. [3].
4) Heuristic of Salami Tactics: if you cannot get the hole salami all at once, try to get it slice by slice. It
means analyze the process as a series of small steps [3].
5) Event Driven Models: the calculations when the temperature changed by a certain amount [3].
6) Time Driven Models: the calculation at a regular time interval [3].
2-6-3 Answer of Question I
The result obtained from the constructed model includes the change in temperature with time for each K as
shown in figure (5). The graph that shows the curve for each K is shown in figure (6).
Page 6 of 9
GE 213, Semester 382
Group#1-Team #3- Member#1: Yaqoub
Assignment No. 3 on Chapter 4
Figure (5): The Change in Temperature with Time for Each K
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GE 213, Semester 382
Group#1-Team #3- Member#1: Yaqoub
Assignment No. 3 on Chapter 4
Figure (6): The Graph Shows the Curve for Each K
2-6-4 Answer of Question II
By using Goal seek the value of K after 6 minutes when the temperature is 38°C is equal to 0.155561245691332.
The curve for this K is shown in figure (7)
Figure (7): The Curve After Changing the Value of K
Page 8 of 9
GE 213, Semester 382
Group#1-Team #3- Member#1: Yaqoub
Assignment No. 3 on Chapter 4
2-6-5 Answer of Question III
The total rate of heat is calculated by using equation (1.2) as shown in table (1)
Table (1): The Total Rate of Heat
The total rate of heat
(kW)
70951812
3. Conclusions
This assignment has been very helpful because it mentioned some of the heuristics that were mentioned in
chapter 4. In addition, it gives some definition of the terminologies that were given in this chapter. The second
part of this assignment was about a small shop selling a hot milk is want an advice to know how much time it
takes to worm the milk. This assignment is very important, because the Goal seek in the Excel work has been
used to make the curve touch a specific point in the graph.
4. References
[1]: Introduction to Microsoft Excel part I: basic.
[2]: Assignment 3 on chapter 4
[3]: HTM, How to Model It, Problem Solving for The Computer Age. Anthony M.Starfield, Karl A.Smith,
Andrew L.Bleloch.
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