FV2204 Computational Engineering Assignment 2 Brief
The work should be word-processed, and submitted the hardcopy through the SCOPE counter . The deadline for submission is 7:30 pm on 06 April 2020 (Monday)
Aims of Assessment
The module aims to provide students with fundamental knowledge and skills of using computing in fire hazard analysis. This includes both essential numerical programming skills required to carry out basic engineering computations within generic programming environments and application of specialist software to solve typical computational problems of fire engineering.
Learning Outcomes
This piece of assessment will test your ability to meet learning outcomes 1-4 as described in your module booklet: –
1. Use and apply Scilab to plot graphs of functions given both analytically and by the data from text files. Incorporate those graphs into reports electronically
2. Apply standard numerical methods of computational engineering, e.g. curve fitting and interpolation, solution of simultaneous linear equations, and statistical processing of experimental data
3. Write Scilab scripts and function to carry out engineering computations and plot complex graphs
4. Demonstrate the use of problem solution tools and evaluative skills in the selection of appropriate methods of analysis
Assignment Details
• This is an individual assignment. Copying from the works of another person constitutes plagiarism, which is an offence with the University’s regulations and will result in a mark of ZERO for the assignment.
• This assignment requires the students to complete ALL questions as attached;
• The word limit is 2500 works (+/- 10%);
• All the assumptions/definitions, comments in the scripts and explanation in your
answers should be clearly stated due to be awarded;
• Submission of all input script files and snapshots of output results are required; and
• This assignment will carry 50% weighting of the total mark for this module.
Submission Details
This assignment should be submitted in hardcopy through the SCOPE counter at TSTE or Kowloon Tong through CANVAS only by the deadline given above and No Hardcopy shall be required. Submission of Turnitin Report is NOT required.
through CANVAS only
14 April 2020 (Tuesday).
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Assignment Details (Learning Outcome: 1-4)
Q1. Consider a two stories school building consists of 2 no. multifunction rooms at G/F and 5 no. classrooms at 1/F. The architectural layout of the school is shown in the sketch below. The headroom of G/F and 1/F is 6 m and 4 m respectively. The multi- function rooms at G/F may involve the usage as assembly hall, lectures or sports centre. Each student shall use EVACNET to predict the egress time of the whole building including G/F and 1/F under the following three scenarios. The details of the study including the main assumptions of the population, calculation of supply data for nodes and arcs, EVACNET network diagram with supply data, input script of EVACNET, and screenshots of EVACNET output results and main findings shall be reported.
1m
Classroom
1m
5m7m8m
Classroom
Classroom
2m Classroom
5m
6m
Legend:
Classroom
Figure 1 – Layout Plan (1/F)
12 m
8m 8m
1m
1m
14 m
8m
Multi-function Room
Multi-function Room
20 m
Not to scale
Figure 2 – Layout Plan (G/F)
a) b) c)
Two staircases are available for evacuation;
The main entrance at G/F is blocked;
One of the staircases is blocked (* Student need to specify the blocked staircase.) Page 2 of 6
Single leaf exit door
0.85m (W) * 2.1m (H)
Double leaves exit door
1.8 m (W) * 2.1m (H)
Q2. Consider the set of parametric equations:
𝑋(𝑡) = 𝑒0.15𝑡𝑐𝑜𝑠2𝑡 𝑌(𝑡) = 𝑒0.15𝑡𝑠𝑖𝑛2𝑡
Create the following plots on the same page: (a) X versus t
(b) Y versus t
(c) Y versus X
Test Case:
Q3. Consider a T-square developing fire with the heat
̇
release rate 𝑄(𝑡). It is assumed that the design fire will
̇ develop from ignition to peak heat release rate 𝑄𝑝𝑒𝑎𝑘
in a t-squared growth rate and then burn out by a t- squared decay rate with the same ratio. The profile is illustrated as below:
Test Case:
–> Q3_plot(“F”,100)
𝑄̇ 𝑝𝑒𝑎𝑘
Fire class
Fire growth rate,
𝛼 (𝑘𝑊/𝑠2)
Ultra-fast
0.1876
Fast
0.0469
Medium
0.0117
T
Time (seconds)
Slow
0.0029
–> Q3_plot(“U”,300)
Assume the fire class is labelled as U – ultra-fast,
F – fast,
M – medium, and
S – slow.
Write a function using Scilab to read the label of fire class and the developing time (T) from ignition to the peak heat release rate and plot the heat release rate
̇
𝑄(𝑡) vs time 𝑡. The peak heat release rate should be
automatically added to the plot title.
𝑄̇𝑝𝑒𝑎𝑘 =𝛼∙𝑇2
Heat release rate (kW)
Q4. Consider steady heat conduction in composite plane walls illustrated as below. According to Fourier’s law, the heat conduction rate (𝑄) is proportional to the section area (𝑆) and the change of temperature (∆𝑇) between surfaces of the single homogenous solid.
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Since heat flow through all sections must be SAME
𝑘 𝑆(𝑇 − 𝑇 ) 𝑘 𝑆(𝑇 − 𝑇 ) 𝑘 𝑆(𝑇 − 𝑇 ) 𝑄=−𝐴21=−𝐵32=−𝐶43
𝑑𝐴 𝑑𝐵 𝑑𝐶
Solving the equations would result in
𝑄= 𝑇1−𝑇4 𝑑𝐴/(𝑘𝐴𝑆)+𝑑𝐵/(𝑘𝐵𝑆)+𝑑𝐶/(𝑘𝐶𝑆)
𝑇 =𝑇 −𝑄𝑑𝐴
Where:
𝑄 – heat loss rate, W
𝑘𝐴 – Thermal conductivity of material A, 𝑊/𝑚 ∙ 𝐾
𝑑𝐴 – Thickness of material A, m
𝑘𝐵 – Thermal conductivity of material B, 𝑊/𝑚 ∙ 𝐾
𝑑𝐵 – Thickness of material B, m
𝑘 – Thermal conductivity of material C, 𝑊/𝑚 ∙ 𝐾 𝐶
𝑑𝐶 – Thickness of material C, m
𝑇𝑖 – Surface temperature at position i=1,2,3,4, K
21 𝑇=𝑇−𝐵
32
𝑄𝑑 𝑘𝐵𝑆
𝑘𝐴𝑆
𝑄𝑑𝐶 43𝑘𝐶𝑆
𝑇=𝑇−
𝑄
𝑄
𝑇𝑇 𝑇𝑇 12 34
Write a Scilab function to read the input parameters in a text file based on the specified format. For example:
Assume the composite plane walls have 2 or 3 different materials. Try to estimate the heat transfer rate (𝑄) and the inner surface temperature and use Scilab to plot the surface temperature verse the distance from the origin of heat flow path.
𝑑𝐴
𝑑𝐵
𝑑𝐶
“Input.txt” Remarks:
500 25 10 4 1.1 125 0.59 30
Test Case:
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Q5. The following equations are used to calculate the thermal response of a detector or sprinkler located at or near a ceiling whose area is large enough to neglect the effects of smoke layer development. When the detector or link temperature reaches its activation temperature, then the detector will be activated.
The rate of temperature rise of the detector response is modelled by
𝑇−𝑇111
𝐷,𝑡+∆𝑡 𝐷,𝑡 =(𝑇 −𝑇 )(1−𝑒−𝜏)+(𝑇
−𝑇 )𝜏(𝑒−𝜏 + −1) 𝑗𝑒𝑡,𝑡 𝜏
𝑗𝑒𝑡,𝑡+∆𝑡 𝐷,𝑡
𝑗𝑒𝑡,𝑡+∆𝑡
∆𝑡
Where
𝜏= 𝑅𝑇𝐼 √𝑣𝑗𝑒𝑡,𝑡
𝑄̇𝑡 1 0.95( 𝑧 )3,
𝑣𝑗𝑒𝑡,𝑡 =
{ 𝑟6
𝑟
𝑓𝑜𝑟 𝑧 ≤ 0.15
11
0.2𝑄̇𝑡3𝑧2, 𝑓𝑜𝑟𝑟>0.15
5
𝑧
2
𝑇 +16.9𝑄̇𝑡3, 𝑓𝑜𝑟𝑟≤0.18
∞5 𝑇= 𝑧3
𝑧
𝑗𝑒𝑡,𝑡
{∞
̇ 𝑄𝑡
𝑟
𝑅𝑇𝐼
𝑇 𝑗𝑒𝑡,𝑡+∆𝑡
𝑇 𝑗𝑒𝑡,𝑡
𝑇 ∞
𝑇 𝐷,𝑡
𝑇 𝑎𝑐𝑡𝑖𝑣𝑎𝑡𝑖𝑜𝑛
𝑣𝑗 𝑒 𝑡 , 𝑡 𝑧
5.38 𝑄̇𝑡 2 𝑟
𝑇+ ()3,𝑓𝑜𝑟>0.18
𝑧𝑟𝑧
Total theoretical fire heat release rate at time 𝑡 (kW)
Radial distance of the detector/sprinkler from the vertical axis of the fire (m) Response Time Index of detector/sprinkler
Temperature of the jet at the next time step, 𝑡 + ∆𝑡 (oC)
Temperature of the jet at the previous time step, 𝑡 (oC)
Ambient space and initial detector/sprinkler temperature (oC)
Detector or sprinkler temperature at time, 𝑡 (oC)
Detector or sprinkler activation temperature, 𝑡 (oC)
Velocity of the ceiling jet gases at the time step, 𝑡 (m/s)
Vertical entrainment distance; the difference between the height of the ceiling and the base of the flames (m)
Assume the fire will develop as a t-square growth fire. Four fire classes “U” – ultra- fast, “F”- fast, “M” – medium and “S” – slow will be considered, same as the definition in question Q3.
Write a Scilab and define the required input parameters such as detector/sprinkler
information, fire class, initial ambient temperature and time step as the input
parameters. Use the above equations to estimate the activation time of the
detector/sprinkler ( 𝑇 ) and required heat release rate to activate the 𝐷,𝑡
detector/sprinkler. Try to plot the detector temperature (𝑇 ) , ceiling jet temperature 𝐷,𝑡
(𝑇 ) and heat release rate versus time. The generated results are also required to be 𝑗𝑒𝑡,𝑡
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automatically saved to a text file in the following format. First 10 rows and last 10 rows in the exported txt file should be attached as a reference.
Marking Criteria for Assignment
The submitted assignment will be marked according to the following criteria:
Test Case:
Questions
Marking Allocation
Marking Criteria
Q1
30
Demonstrate the use of EVACNET and evaluative skills on the designed evacuation scenarios to estimate the egress time for the building
Q2-Q4
45
Use and apply Scilab to plot graphs of functions given and read input data from external text file to generate sound outcomes or findings.
Q5
25
Use and apply Scilab to carry out numerical methods of computational engineering and plot complex graphs
Total
100
– END OF ASSIGNMENT –
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