A rapid compression machine with crevice containment

A rapid compression machine (RCM) incorporating ‘crevice containment’ is designed and fabricated. ‘Crevice containment’ maintains the advantage of suppression of piston-motion induced roll-up vortex while avoiding undesirable multi-dimensional effects of crevice. The geometry of the combustion chamber is optimized with computational fluid dynamic simulations. The designed RCM is demonstrated to provide highly reproducible experimental data at compressed gas pressures up to 100 bar. Pressure traces also reveal that ‘crevice containment’ leads to significant reduction in the post-compression pressure drop. Further, the importance of ensuring instrumentation calibration and avoiding thermal shock of pressure sensor is highlighted to avoid systematic errors in measurements. High fidelity experiments are conducted for autoignition of hydrogen at compressed pressure of 50 bar. The experimental data is properly modeled by the kinetic mechanism from O’Conaire et al. [M. O’Conaire, H.J. Curran, J.M. Simmie, W.J. Pitz, C.K. Westbrook, Int. J. Chem. Kinet. 36 (11) (2004) 603–622] and discrepancy is noted from a recent mechanism [Z. Hong, D.F. Davidson, R.K. Hanson, Combust. Flame 158 (2011) 633–644].