FV2204 Computational Engineering Assignment 2 Brief
The work should be word-processed, and submitted online to Canvas unless specified below. The deadline for submission is 23:59 on 12 April 2021 (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 online to Canvas by the deadline given above. Submission of Turnitin Report is NOT required. Five days rule will be applied for any late submission, i.e. 40% mark is capped.
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Assignment Details (Learning Outcome: 1-4)
Q1. The architectural layout of the 2-stories building is shown in the sketch as below. The headroom of G/F and 2/F is 5 m and 3 m respectively. The multi-function rooms at
G/F may involve the usage as assembly hall or exhibition functions.
(40 Marks)
1m
Office
Office
Meeting Room
Office
Office
1m
2m
6m
Legend:
5m7m8m
4m
6m
.5
Figure 1 – Layout Plan (2/F)
8m 8m
1m
1m
14 m
20 m
8m
Single leaf exit door
0.8m (W) * 2.0m (H)
Double leaves exit door
1.8 m (W) * 2.0m (H)
12 m
Multi-function Room
Multi-function Room
Not to scale
Figure 2 – Layout Plan (G/F)
Each student shall use FDS+Evac to study the occupants’ evacuation of the whole
building including G/F and 2/F under the following three scenarios.
a) Fire Drill Model: No fire is involved. All the exits and staircases are available for evacuation. Detection time is assumed as 0s.
b) Evacuation Scenario A – Front entrance at G/F is blocked by fire at T=120s. Fire affecting area at front entrance is around 2m*2m close to the door centre. Detection time is assumed to be 20s.
c) Evacuation Scenario B – Upper landing area to the left staircase is blocked by fire at T=60s. Fire affecting area to the left staircase is around 2m*2m close to the exit door of meeting room. Detection time is assumed to be 30s.
To demonstrate your works, the assignment shall incorporate the below items: Page 2 of 5
(1) you will have to report the main assumptions of the occupants in each space, occupants’ profile including pre-movement time assumption, unimpeded walking speed on horizontal floor or downward stairs, etc. for each scenario.
(2) FDS+Evac input scripts shall be provided.
(3) The simulation results shall be summarized in the RSET table to indicate the
clearance time for each room and floor.
(4) Evacuation screenshots in every 30 seconds shall be provided.
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
(10 Marks)
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
Slow
0.0029
T
Time (seconds)
–> 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 function shall output the results
of time and heat release rate automatically to an external file. (20 Marks)
𝑄̇𝑝𝑒𝑎𝑘 =𝛼∙𝑇2
Heat release rate (kW)
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Q4. 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 𝑇= 𝑧3
𝑧
5
𝑧
2
𝑇 +16.9𝑄̇𝑡3, 𝑓𝑜𝑟𝑟≤0.18
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 function and define the required input parameters such as
detector/sprinkler information, fire class, initial ambient temperature and time step as
the input arguments for the defined function. Use the above equations to estimate the
activation time of the detector/sprinkler (𝑇 ) and required heat release rate to 𝐷,𝑡
activate the detector/sprinkler. Try to plot the detector temperature (𝑇 ) , ceiling jet 𝐷,𝑡
temperature (𝑇 ) and heat release rate versus time. The generated results are also 𝑗𝑒𝑡,𝑡
required to be automatically saved to a text file as illustrated in the test case. First 10 Page 4 of 5
rows and last 10 rows in the exported txt file should be attached as a reference. (30 Marks)
Marking Criteria for Assignment
The submitted assignment will be marked according to the following criteria:
Test Case:
Questions
Marking Allocation
Marking Criteria
Q1
40
Demonstrate the use of building evacuation model (FDS+Evac) and evaluative skills on the designed evacuation scenarios to estimate the egress time for the building
Q2-Q3
30
Use and apply Scilab to plot graphs of functions given and read input data from external text file to generate sound outcomes or findings.
Q4
30
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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