The Development Of Cylinder Pressure Acquisition And Combustion Analysis

Due to the impact of the world energy crisis and environmental issues, the demand ofautomobile engine increased fast, then people made three main themes of the automotiveindustry: environmental protection, energy conservation and security. However, both thedevelopment of the engine and the engine characteristics need the experimental test andmeasurement. According to the existing equipment, we developed the acquisition ofcylinder pressure and combustion analysis system, then we can collect and analyze data.MPLAB is used to write the acquisition program of the Next-bit machine to realizethe data collection process, we calibrated the dynamic top dead centre by reversed towingmethod to provide accurate information for the experiment. Combination ofObject-oriented programming methods, we used C++Builder to design the data acquisitionand analysis system software of PC. The acquisition interface is simple and practical, easyto operate and high expansion. It can also calculate an average of data. Data analysisprocess provides two data smoothing methods. We can display the indicator diagram, andcompared with the data after smoothing. We used the indicator diagram to calculate therate of combustion heat release for the data processing. Then we can draw the heat releaserate curve of combustion to display the combustion process.Experiments used OMRON E6B2-CWZ6C Model rotary encoder to measure thecrankshaft phase signal, and selected the Dytran charge type pressure sensor2300C4tocollect cylinder pressure signal. Experiments tested the cylinder pressure of differentIgnition advance angle. We can study the heat flux in-cylinder combustion process whichimpacted by ignition advance angle by drawing the cure of combustion heat release rateand heat flux density. Then we can get the engine cylinder heat transfer process thatignition advance angle impacted.The acquisition and analysis system is simple and practical, cost-effective, and leavesenough space to develop. We can continue to increase the number of data acquisitionprocess, and build an experimental platform for the future work research.