Experimental & Computational Modelling of Experiment 2: Flow over an Aerofoil and Experiment 3: Stress Concentrations

Faculty of Science & Engineering

EGA324 Mechanical Engineering Practice

Session 2021-22

Supplementary Coursework – Experimental & Computational Modelling (E2 & E3)

This supplementary assignment is based on both the Experimental & Computational Modelling of Experiment 2: Flow over an Aerofoil and Experiment 3: Stress Concentrations completed during TB2

For this supplementary submission remove these guidelines. Restrict yourself to a total 13 page limit – 1 page coversheet (as given at the start of this document) and 6 pages per experiment.

You are to complete a technical report on the computational modelling you have carried out and how it compares to your experimental results for each experiment utilising the following headings (6 pages per expt), with some guidance provided below (refer to course notes for further details):

• Summary and Objectives
  • Brief introduction and aims of experiments/computational model/s along with the key details and findings.
  • Comparisons between experimental/computational data, previously published and/or theoretical estimates.
  • Any significant findings claimed in the summary should tally to your discussion and conclusions sections
• Experimental Methodology
  • Experimental setup, equipment & apparatus – what was measured during the experiment?
  • Criticial specimen dimensions & geomteries
  • Experimental progamme detail: independent, dependent and any environmental variables
  • Number of repeats to minimise experimental error/uncertainty
• Computational Methodology
  • How was the model built-up? What specific capabilities and physics were modelled in ANSYS? How was the model deemed to be accurate (mesh sensitivity)?
  • Show geometry/boundary conditions and a typical mesh.
  • Sensitivity to boundary conditions – were any boundary conditions subject to sensitivity testing?
  • Is the modelling in ANSYS on finite element or finite volume based? 2D or 3D? Transient or steady-state? Non-linear or linear?
  • What material properties are used in the model? Are these as close as they could be to reality?
• Results
  • Refer to the course notes for a more detailed description for the minimum results to be included in this section – both experimentally and computational – these should be plotted on the same figures to avoid unnecessary using space
• Discussion
  • Aerofoil:
    • Describe the shape of the pressure distributions over the aerofoil using Bernoulli’s equation.
    • Indicate the stall angle and describe how you determined that value – does the modelling work corroborate/validate these results?
    • Explain your results – what happens to the flow over the aerofoil as it approaches and goes beyond the stall angle? How are the pressure and velocity connected along a streamline?
  • Stress Concentration
    • Rank the five stress raisers in terms of their impact on the components’ behavior under load.
    • How does the size of the hole affect the tensile characteristics of the components and why – does the modelling work corroborate/validate these results?
    • Compare and contrast the degree and form of the deformation (strain) at failure for the different stress raisers and how do they compared with the plain specimen?
    • How do the shapes of the fracture surfaces compare and why might they be different?
    • Comparsion using Neuber’s rule with empiricals SCFs?
  • Throughout this section should include some description of any modelling (including contours plots or summary of modelling data) which can be validated against the experiments
  • How can the discrepancies between model and experiment be reduced?
  • How could the modelling be improved? Is the correlation consistent?
  • You are not answering all these questions directly, but they help to form the basis of your discussion. Not all questions need necessarily to be answered – just what is relevant and justifiable from your own results.
• Conclusions
  • Concisely summarise the points from your discussion.
• References
  • Minimum 4 references for each experiment/simulation which are relevant, and cited in a consistent and appropriate format such as Harvard or Vancouver.

A consistent and professional format is expected along with appropriate labelling and captioning for any figures/tables used.

The University adopts a zero tolerance policy towards plagiarism and unfair practise, this includes use of somebody elses laboratory data, copying of material from other students, copying of past work, use of non-referenced material from the internet of publications.

CITATION