Modify the linear friction equation

Instructions for Engine Modeling Mini-Project

In this project, you will simulate a 4-stroke spark-ignition, naturally aspirated engine using a MATLAB two-zone heat release model. You will choose an engine about which the bore, stroke, connecting rod length, and other manufacturer’s information can be found. Based on the engine chosen, you will modify the volumetric efficiency and engine friction as a function of engine speed. You will also assign air-fuel ratios to different engine operating points and determine MBT timing. You will be expected to relate your findings to typical engine design/operating parameters we have explored in this course.

4. Based on the chosen engine, modify the linear friction equation. The friction equation provided in the two-zone script (line 53) is adjusted for motorcycle operation. Reference your textbook or Blair’s textbook (cited in Jeremy’s thesis) for help adjusting this. Site any external sources that you use.

5. Based on the chosen engine, construct a custom air-fuel ratio map over your engine’s operating range. You might be able to find an aftermarket map, or you might have to make assumptions based on the type of engine. This is for the purpose of step 6; don’t get too obsessive about this. Site any external sources that you use.

10. By running the “BSFCcode.m” file, a BSFC map will be produced. Construct NO and HC emissions maps by adding additional lines and plots to the “BSFCcode.m” file (i.e. NO and HC emissions should already be stored in the Excel file, simply plot these in the same way as RPM, Torque, and BSFC values were plotted to create BSFC maps).

Your deliverables include:

• Plot and discussion of actual as well as theoretical power and torque as a function of speed

• Plot and discussion of BSFC map for your engine