- Physics(Graph-Only Report)

U04521 - Engineering Thermofluids Coursework 1 - Gasoline Engine Testing and Analysis of Performance Coursework 1 for module U04521 is worth 20% of the total module assessment, and includes two assignments: a “Graphs-only” technical report on engine test results; an online quiz on engines working principles and operation. Both assignments are compulsory for all students. Successful completion of coursework 1 requires knowledge and understanding of the internal combustion engines, and the ability to apply fundamental techniques for data analysis. This relies on the theory delivered during lectures, the knowledge acquired during the lab session, as well as a certain amount of independent work and research. Coursework 1 includes a 2-hour lab session dedicated to engine testing and data collection and analysis. During each lab session, the stock BMW GDI Engine will be tested and experimental data collected and given to each group of students for analysis. Two different sets of tests will be performed, “Fixed Engine Speed Test” and “Fixed Throttle Position Test”. The objectives of Coursework 1 At the end of coursework 1, the students should have gained the following skills and abilities: 1. Be familiar and able to describe test-engine, engine-rig instrumentation and data acquisition systems; 2. Knowledge and understanding of the most fundamental engine working principles; 3. Knowledge and ability to apply techniques for evaluation and analysis of engine efficiency and performance parameters; 4. Use of spreadsheet for data processing and presentation of results in graphical form. 5. Develop familiarity with the use of information technology as an effective tool to aid in the learning process. The Test Engine The investigation will be performed using the stock BMW, supercharged, intercooled, 4-cylinder, 4- stroke, 1.6 litre, Direct Injection (DI), Spark Ignition (SI), Mini Cooper-S engine. Essential technical specifications of the test engine are presented in table 1. The CP CADET v14 dynamometer control and acquisition system will be used to acquire experimental data useful for efficiency and performance analysis. Bore (mm) 77.0 Stroke (mm) 85.8 Connecting Rod Length (mm) 138.4 Compression ratio 10.5 : 1 Rated Power 132 kW @ 6000 rpm Rated Torque 240 Nm @ 4000 rpm Table 1 Fixed Throttle Position Test The engine is tested in steady-state thermodynamics conditions at various throttle opening positions. At each fixed throttle setting, the engine speed is increased in steps and relevant data are collected. These include: Engine Speed (RPM); Dynamometer Torque (Nm); Fuel Consumption (g/s); Throttle Position (%); Intake Temperature (°C). Fixed Engine Speed Test The engine is subsequently tested at one constant engine speed and increasing torque (i.e. throttle opening position). Steady-state data are also collected and given to the students (via Moodle) for analysis. At each operating conditions, pre-determined settings of fuel injection timing/quantity and spark timing are used according to the engine ECU (Electronic Control Units). The assignments for coursework 1 Coursework 1 includes two assignments: - An individual “Graphs-only” technical report on engine test results; - An online quiz on Internal Combustion Engines working principles and operation. Please note that both elements are compulsory. Useful material, deadlines and information about submission are available in the relevant U04521 Moodle pages (e.g. in the module handbook). Graphs-only Technical Report Each lab session, students are given the experimental data for analysis of engine performance and efficiency. Data will be ordered by set and date and published on Moodle. The individual report must include results in graphical form (e.g. Excel plots/charts) and no text. Brief comments can only be added as caption of each plot, if relevant. The report will be submitted via Moodle. The assessment will consider: expected trends, numerical values, units, completeness and quality/readability of the plots. The graph-only report is worth 40% of the total coursework mark. Expected plots for Fixed Throttle Position Test: - Torque vs Speed (2 curves, one per each throttle position); - Break Power vs Speed (as above); - Volumetric Efficiency vs Speed (as above); - Break Specific Fuel Consumption (BSFC) vs Speed (as above). Expected plots for Fixed Engine Speed Test: - Brake Power vs Brake Mean Effective Pressure (BMEP); - Fuel Consumption vs BMEP; - BSFC vs BMEP; - Brake Thermal Efficiency vs BMEP. Online (Moodle-based) Multiple-Choice Questionnaire The assignments for coursework 1 include a technical quiz (MCQ) during which the fulfilment of the above objectives and a broader understanding of engine working principles are demonstrated and assessed. The online quiz is worth 60% of the total coursework mark. Possible questions include, but are not limited to: x Gasoline and Diesel engine working principles; x Performance and efficiency characteristics; methods used for analysis and calculations; x Operating conditions investigated, and the techniques used to collect the experimental data during the lab sessions; x The nature and meaning of engine torque against speed and power against speed characteristics and correlation with volumetric efficiency. x The nature and meaning of consumption loop for both gasoline and diesel engines. References 1. U04521 Course Notes and Presentations 2. Eastop, T D and McConkey, A, Applied Thermodynamics for Engineering Technologists, Longman, 1993 5th edition. 3. Ferguson, C R, Internal Combustion Engines, Wiley, 1986. 4. Heywood, J B, Internal Combustion Engine Fundamentals, p842, McGraw Hill 1988. 5. Stone, R, Internal Combustion Engines, MacMillan 1992 2nd edition.