Measurement and prediction of detonation cell size in binary fuel blends of methane/hydrogen mixtures.

In this study, detonation cell sizes of binary fuel blends of methane–hydrogen–oxygen mixtures with different compositions (i.e., CH 4 –2H 2 –3O 2 , CH 4 –H 2 –2.5O 2 and CH 4 –4H 2 –4O 2 ) are experimentally measured. Good agreement is found between the experimental data and predictions based on the chemical length scales obtained from a detailed chemical kinetic model. The results show that detonation structure in methane–hydrogen–oxygen mixtures are irregular and detonation cell size ( λ ) for CH 4 –H 2 –2.5O 2 mixture is larger than CH 4 –2H 2 –3O 2 and CH 4 –4H 2 –4O 2 mixtures. A linear relationship is determined by: λ = 34.62 Δ I , through scaling the detonation cell size with the ZND induction zone length ( Δ I ) for methane–hydrogen–oxygen mixtures, and this scaling function is universal in CH 4 –H 2 –O 2 mixtures at three compositions. [ABSTRACT FROM AUTHOR]