The Development of Data Capture/Analysis System for the Use in Cold Start Investigation 890002
This system was developed to solve the problem of acquiring a large number of consecutive engine cycles of various parameters required to analyse the cold start/run-up behaviour of an engine, and display the acquired data in an easily digestible form.
Data is acquired using a 12 bit analog to digital converter at a wide acquisition rate up to a maximum of 500K sample/sec and to a memory depth of 2000K bin 16 bit reading/channel of dynamic RAM.
The acquired data can be displayed on an oscilloscope, a variety of Y/T or digital plotters or transferred to an IBM PC computer for further processing.
Various programs were developed for the IBM PC to analyse data for the whole cold start/run-up period. The system is capable of plotting the acquired parameters in three dimensional graph form, calculating the average speed for each of the engine cycles and performing a simple heat release analysis for each cycle.
The system was used in the analysis of the cold start and run-up behaviour of a 4 cylinder diesel engine. The engine was instrumented for cylinder pressure, fuel line pressure and needle lift for each cylinder, together with a sweep start and degree marks. The three dimensional graphs showing cylinder pressure for all four cylinders for 660 consecutive cycles reveal that one cylinder can accelerate the engine to flight speed with very limited assistance from the other cylinders.
The system proved to be a very useful tool for reducing the time required for the analysis of cold start/run-up data and may prove to be of great assistance in understanding the fundamental behaviour of a multi-cylinder engine during such a critical period.