ENGT 5141 Advanced Thermodynamics and Heat Transfer Assignment – De Montfort University, UK
Assignment Title – CFD Analysis in Heat Transfer & Combustion
Learning Outcomes – The learning outcomes that are assessed by this coursework are:
LO1 – Demonstrate proficiency in analysing advanced thermal cycles and heat transfer modes and their applications.
LO2 – Design and model heat and mass transfer on complex geometries using commercial or in-house computational codes and critically evaluate the results.
AIM – The overall aim of this assignment is to demonstrate that you have a clear understanding of Thermal Analysis and Computational Fluid Dynamics (CFD) Methods, and the role these techniques play in development of heat and mass transfer systems, the benefits associated with their use and the problems and limitations encountered when using these methods.
The above aim is to be achieved through a written report, not exceeding 3000 words.
CASE STUDY I – In a heat recovery system, Cold water enters the counter-flow helical heat exchanger at Tc,inoC at a rate of m·A kg/s, where it is used to recover heat from engine oil that enters the heat exchanger at Th,inoC at a rate of m·B kg/s. For the bench mark case use a pitch distance of 100mm for the helical coil.
Each student will generate 2 case studies – A bench mark case which corresponds to the boundary conditions in the table below – ( Use the row that matches the last ID of your student P No). And another case where you optimise the design and operation of the heat exchanger. The objective is to optimise the rate of heat transfer, within the constraints of 1m length and a fixed outer shell diameter of 250mm. Flow rates must be realistic!
Each student will use the following details for a base case and then optimise the heat transfer
|
Last Digit of Student ID |
Tc,in oC |
Th,in oC |
m·A kg/s |
m·B kg/s |
|
0-1 |
5 |
120 |
4 |
8 |
|
2-3 |
7 |
110 |
4 |
9 |
|
4-5 |
10 |
100 |
4 |
10 |
|
6-7 |
12 |
90 |
4 |
11 |
|
8-9 |
15 |
80 |
4 |
12 |
|
Penultimate Digit of Student ID |
Tube diameter (mm) |
Shell diameter (mm) |
Interface thickness (mm) |
|
0-1 |
20 |
250 |
5 |
|
2-3 |
22.5 |
250 |
10 |
|
4-5 |
25 |
250 |
15 |
|
6-7 |
27.5 |
250 |
20 |
|
8-9 |
30 |
250 |
25 |
You will need to work through the following steps –
A. Geometry Creation: using Ansys Design Modeller or importing from other CAD software such as Creo, Solidworks. etc
B. Meshing the geometry: (Mesh)
C. Setting the boundary conditions: (setup)
D. Performing the simulation (Solution ): Ansys fluent solver (steady state calculation)
E. Post processing the results:
CASE STUDY II – The burner with the dimensions below should be built on meshed and solved in Ansys workbench using a basic combustion model (for methane-air mixture or any other mixture the student may opt to go for should be set in.
|
Last Digit of Student ID |
D(mm) |
|
0-1 |
55 |
|
2-3 |
60 |
|
4-5 |
63.5 |
|
6-7 |
65 |
|
8-9 |
70 |
Deliverables to be submitted for assessment: Written report
1. Presentation/structure
Aims/Objectives should be stated clearly and concisely.
Report should have clearly defined sections such as: Introduction, Review,
Methodology, Results/ Discussion , Conclusions, References , etc.
2. Introduction/background
Role of CFD and Computational Heat Transfer methods in modelling and design of thermo -fluid systems
3. Review
The numerical methods used for convective heat transfer , combustion and fluid flow (CFD) and the latest development in these fields the basic theoretical principles underpinning modern computational Heat Transfer and CFD.
Role of CFD and Computational Heat Transfer methods in modelling and design of thermo -fluid systems.
4. Methodology
Mesh convergence and boundary conditions.
Calculations to make decision and check results.
5. Results and Discussion
Discussing results of your case study: briefly interpreting and discussing the results and comparing it to the bench mark.
General visualisation of the flow and temperature field may include:
- Contours of velocity, temperature, pressure and any other relevant parameter.
- Vertical and axial profiles for velocity and temperature at specific location of interest
- Horizontal as well as cross -sectional images of velocity profiles coloured with other variables.
You should demonstrate understanding of theory of Navier -Stokes equation of motion and the various turbulence modelling used in CFD and in solving the 3D convective heat transfer equation (steady state only).
Discuss the benefits that can be gained from using modern CFD and Computational Heat Transfer methods.
Discuss the limitations and problems associated with the use of CFD and Computational Heat Transfer methods.
6. Conclusion
7. References/Appendices
At least 7 academic references.
