The Development And Experiment Of Rapid Compression-expansion Machine

The mechanism of knock is still unclear although tremendous researches andefforts have engaged in knock study. In order to study knock mechanism a rapidcompression-expansion machine (RCEM) based on hydraulic system was developed.Firstly, introduced the research status at home and abroad. As well as theadvantages and disadvantages of RCEM. The RCEM has advantages of wide visiblezone, high compression ratio, relative compact structure and fairly short compressiontime. Then introduced the experimental machine several important system and thestructure were introduced in detail,mainly including hydraulic driving system,, thepiston group and heating system, the preparation of mixture, control and dataacquisition system, etc.Then a1-dimensinal model was established in AMESim in order to simulate theRCEM performance. The simulation analyze the quality of source of hydraulicpressure, the piston group, ignition phase on the factors that affect the law of motionof the piston, and the source of hydraulic pressure and orifice area of the impact onthe compression ratio. Simulation showed that within the scope of the limit ofcompression ratio, under the constant orifice diameter, the greater the hydraulicpressure source was, the compression ratio is larger; when hydraulic pressure sourcewas under constant pressure, the greater the throttle aperture was, the compressionratio is larger;Lastly, the experimental results showed that the in-cylinder pressure ofexperiment agrees very well with simulation, but the peak pressure of in-cylinderdiffers mainly due to compression ratio estimation error and heat transfer difference.The pressure consistency reaches an excellent level with a maximum peak pressurediscrepancy ratio3.2%. Variable parameters through the prototype experiments on thedevice, the HCCI, spark ignition and detonation combustion process wereimplemented which showed that the device can not only study the detonation ofcombustion, also be used for a variety of other experimental simulation of the processof research.