| Module code and title | Mechanical Engineering Principles-4MA017 |
| Module guide | https://canvas.wlv.ac.uk/courses/28788/external_tools/927 |
| Module leader | XXXXXXXXXX XXXXXXXXXXX XXXXXXXXXXXXXX XXXXXXXXXXXXXXX |
| Assignment name | Kinematic and thermodynamic analysis of crank-slider system |
| Assignment type | Coursework |
| Assignment weighting | 50% |
| Submission date | 22-04-2022 |
| Submission method | Online submission via CANVAS |
| Assignment requirements | Calculator, engineering drawing tools, access to Microsoft office, access to internet. |
| Assessment criteria | Task L.O. Code Learning Outcome Criteria Show knowledge and understanding of classic mechanical 1, 2 1 engineering principles such as thermodynamic, fluid mechanics and theory of machines. Demonstrate an understanding of the real-life applications of 1, 2 2 the basic engineering principles and the role of these principles in the modern engineering systems and products. Apply mathematical and analytical tools associated with 1, 2 3 thermos-fluids and theory of machines to analyse and synthesise relevant engineering components and systems. Demonstrate the ability to conduct research and investigations 1, 2 4 to establish and broaden the scientific knowledge in the relevant engineering fields. |
| Additional instructions | All questions must be attempted The assignment report must be prepared using ‘Word’, then saved as pdf format, and then it should be submitted via CANVAS using this link. For task 1, the mechanism drawings should be generated using hand drawings and the graph should be generated using MS Excel. For calculations, round all calculated answers to three decimals digits. For calculations, the direct answer is not accepted; you should detail the process of achieving the answer. Marks might be assigned for the necessary sub calculations. All used sources must be well referenced. |
| Professional Body requirements | None |
| University Regulations | University’s Academic Regulations: https://www.wlv.ac.uk/about-us/governance/legal- information/policies-and-regulations/academic-regulations/ Academic Integrity Policy: https://www.wlv.ac.uk/media/departments/office-of-the-vice- chancellor/documents/Academic-Integrity-Policy-from-2019-20.pdf Performance descriptors are linked here: LevelandMarkDescriptors |
| Support | Student Support and Wellbeing: https://www.wlv.ac.uk/current-students/student-support/student- support-and-wellbeing-ssw/ Study Guides: https://www.wlv.ac.uk/lib/skills-for-learning/study-guides/ Online Student Handbook: https://www.wlv.ac.uk/current-students/student-handbook/ Assessment information: http://www.wlv.ac.uk/assessment You should also refer to your Course and Module Guides |
| Date by which feedback will be provided | May 2022 |
| Method by which feedback will be provided | CANVAS |
| Task (1): Position analysis and kinematic diagram (50 marks) | |
| A. In the offset crank-slider mechanism O2AB, shown in Figure 1, O2 is fixed; the slider B travels along a vertical path which is at a distance of 1 cm to the right of O2; O2A is 3 cm long and rotates anti-clockwise about O2; the length of the connecting bar AB is 6 cm. | |
| i. Conduct a position analysis for the mechanism and plot a graph showing the variation of the slider displacement with the crank angle. Assume the initial position of this mechanism is when the crank is horizontal. You will need to draw the mechanism at different values of the crank angle (take an increment of 45o for the crank angle) and you should present these drawings in your report. You will need also to generate a table presenting the different values of the crank angle against the corresponding slider displacement. The mechanism’s drawings should be generated using hand drawings and the graph should be generated using MS Excel. | [30 marks] |
| ii. Determine the stroke length of the slider. | [5 marks] |
| iii. If the cycle time of the mechanism is 4 sec, determine the rotation speed of the crank in rpm. | [5 marks] |
| B. A sketch of a toggle clamp used to securely hold parts is shown in Figure 2. Draw the kinematic diagram of the mechanism. | [10 marks] |
Figure 2: Toggle clamp | |
| Task (2): Thermodynamic analysis (50 marks) | |
Figure 3: Air properties and piston dimensions at 270o crank angle | |
| Assume that the slider of the mechanism, shown in Figure 1, is a part of a piston-cylinder device, shown in Figure 3, that contains 0.15 m3 of air when the crank is at an angle of 270o. The diameter of the cylinder is 24 cm and the mass of air within the cylinder is 180 g. When the crank rotates the volume of the air in the cylinder changes while its pressure is maintained constant at 101 kPa. | |
| a) Determine the specific volume, density, and temperature of the air in the cylinder when the crank is at an angle of 270o. | [15 marks] |
| b) Determine the specific volume and temperature of the air when the crank is at an angle of 90o. | [25 marks] |
| c) Determine the work required to compress the air when the crank rotates from 270o to 90o. | [10 marks] |
END OF THE ASSIGNMENT BRIEF
