Instrumentation For Relative Cylinder Power Measurement On Internal Combustion Engines
Emin Yilmaz · 2020
The goal of design projects is to introduce students to designing mechanical systems in the ETME475-Mechanical Systems Design course.Purpose of this project was to design a sensor assembly to measure relative power of individual cylinders on an internal combustion engine.Basic sensor assembly was completed as a laboratory requirement for the course.The sensor assembly consists of an optical encoder, a sensor holder frame and a handle.A pulley is attached to the shaft of the encoder.An O-ring is fitted over the groove of the pulley.When pressed against it, the pulley can ride on crankshaft belt of an idling internal combustion engine.Pulses generated by the encoder are acquired and stored in a file using National Instruments 1 PCI 6023E data acquision board and National Instruments LabVIEW data acquisition software.Stored data is processed using LabVIEW software and results are displayed.Variation of frequency of the signal is proportional to the belt speed.Belt speed is related to the power generated by individual cylinders on the engine.During power stroke belt speed increases, whereas during compression stroke belt speed decreases.Therefore magnitude of peaks on a plot of frequency as a function of time (or, in this case, sample number) gives an indication of relative power generated by each cylinder.Plot is generated for two revolutions of the crankshaft.