Please I need explanation and answers

Please explanation And answer

Faculty of Computing, Engineering & Media (CEM)
Coursework Brief 2023/24
Module name:
Structural Dynamics and Aeroelasticity
Module code:
ENGA3005
Title of the Assessment:
Report
This coursework item is: (delete as appropriate)
Summative
This summative coursework will be marked
anonymously: (delete as appropriate)
No
The learning outcomes that are assessed by this coursework are:
1. Systematic understanding of concepts and methods of structural dynamics and aeroelasticity
using appropriate physical and mathematical models.
2. Ability to implement the acquired knowledge in an aircraft design process by means of a case
study.
This coursework is: (delete as appropriate)
Individual
If other or mixed … explain here:
This coursework constitutes 50 % of the overall module mark.
Date Set:
24/10/2023
Date & Time Due (the deadline):
08/12/2023 at 12.00 noon
In accordance with the University Assessment and
Feedback Policy, your marked coursework and feedback
will be available to you on:
08/01/2023
You should normally receive feedback on your coursework no later than 15
University working days after the formal hand-in date, provided that you
have met the submission deadline
If for any reason this is not forthcoming by the due date your module leader will
let you know why and when it can be expected. The Associate Professor Student
Experience (CEMstudentexperience@dmu.ac.uk) should be informed of any
issues relating to the return of marked coursework and feedback.
When completed you are required to submit your coursework via:
The submission link on learningzone
Late submission of coursework policy:
Late submissions will be processed in accordance with current University
regulations.
Please check the regulations carefully to determine what late submission
period is allowed for your programme.
Academic Offences and Bad Academic Practices:
Please ensure you read the section entitled “Academic Offences and Bad
Academic Practice” in the module handbook or the relevant sections in this link:
BaseCamp Link: Overview: Assessment and Good Academic Practices
Tasks to be undertaken:
Tasks outlined in the instructions for report
Deliverables to be submitted for assessment:
Report and Matlab scripts
How the work will be marked:
The report will be marked by a marking rubric.
Module leader/tutor name:
Weigang Yao
Contact details:
weigang.yao@dmu.ac.uk
Should you need any further information or advice please email
cemadvicecentre@dmu.ac.uk
ENGA3005: Structural Dynamics and Aeroelasticity
Assessment: Report (3000 words)
Introduction:
Lightweight structures offer many feasible design features for future fuel efficient,
environmentally friendly aircraft to help to deliver on the decarbonization strategy. However,
the use of lightweight structures is constrained by aeroelastic effects such as flutter, static
divergence and control surface reversal, etc. This assignment is designed to provide you with
the practical understanding of static/dynamic aeroelastic analysis using two-system coupling
and analytical approaches.
Submission:
S1: Matlab scripts.
S2: Report presenting details of the analysis and conclusion.
Marking specification:
Task 1: 10%
Task 2: 35%
Task 3: 45%
Structure of the report: 10%
TASKS
Task 1: Explain what the static and dynamic aeroelasticity are using the Collar’s
triangle. (10 marks)
Task 2: static aeroelastic analysis of an airfoil section: Elastic twist (35 marks)
1) Use a diagram to explain what the two-system coupling strategy is? (5 marks)
NOTE: You will need to explain what the two systems are, and how to couple the two systems for static
aeroelastic analysis using a diagram.
2) An airfoil section is elastically mounted on a torsional spring as shown in Figure 1. Flow
conditions and structural parameters are given in table 1.
ENGA3005: Structural Dynamics and Aeroelasticity
Figure 1. A symmetric, thin airfoil section elastically mounted on a torsional spring,
where ac is the aerodynamic centre.
Table 1. Flow conditions and structural parameters
Description
Symbol
Value
Initial angle of attack
Freestream density
Elastic centre
Torsional stiffness
chord
α0
ρ∞
e
kα
c
1°
1.225 kg/m3
0.2c
300 Nm/rad
1m
a) Implement the two-coupling strategy in MATLAB to compute the elastic twist for the
aeroelastic system and validate your code by comparing your results with the
analytical solution for a range of freestream velocity by assuming constant torsional
spring stiffness, and linear aerodynamics. (20 marks)
NOTE: You will need to compute and compare your results for three freestream velocities.
b) Explore how to reduce the elastic twist using the MATLAB program you developed.
(10 marks)
Task 3: Dynamic aeroelastic analysis of an airfoil section: Flutter onset (45 marks)
1) What is flutter and explain why it is an important design consideration in future aircraft
design? (10 marks)
2) A pitch/plunge aeroelastic system is shown in Figure 2, and the flow conditions and structural
parameters are given in table 2.
ENGA3005: Structural Dynamics and Aeroelasticity
Figure 2. A symmetric and thin airfoil section elastically mounted on a translational/torsional spring.
Table 2. Flow conditions and structural parameters
Description
Symbol
Value
Mass unbalance
Radius of gyration
Pitch frequency
Frequency ratio
Mass ratio
chord
Freestream density
Freestream temperature
xα
rα
ωα
ωh/ ωα
µ
c
ρ∞
T∞
0.25
0.5
45 rad/s
0.3185
100
1m
1.225 kg/m3
273 K
a) Write a MATLAB function and convert the EOM of the structural system into a statespace model. (5 marks)
b) Assuming the elastic centre is at a quarter chord, develop a MATLAB program to
construct the aeroelastic system in a state space formulation using Theodorsen theory
to predict flutter onset Mach number. (25 marks)
NOTE: You will need to plot the eigenspectrum as a function of Mach number, and the structural
response at the flutter onset.
c) Explore how the position of elastic centre influences the flutter onset using the
MATLAB program you developed. (5 marks)
THE END