The pressure and deflagration to detonation transition(DDT)characteristics of acetylene and oxygen flame were studied in a detonation tube.The pressure history and the flame velocity along the tube were measured with ...The pressure and deflagration to detonation transition(DDT)characteristics of acetylene and oxygen flame were studied in a detonation tube.The pressure history and the flame velocity along the tube were measured with high frequency pressure transducers and ion probes.By analyzing the data recorded in the experiment,the detonation wave pressure,post wave pressure and DDT distance were obtained,together with the effects of the initial pressure varying from 2×10^(4)Pa to 10^(5)Pa,equivalence ration from 0.3 to 1.0,and mixture concentration from 60%to 100%.It was found that the detonation pressure was decreased respectively with the decrease of initial pressure,equivalence ratio and mixture concentration,but the DDT distance was enlarged.The DDT distance was found particularly sensitive to mixture concentration.展开更多
To satisfy the needs of large-scale hydrogen combustion and explosion simulation,a method is presented to establish single-step chemistry model and transport model for fuel-air mixture.If the reaction formula for hydr...To satisfy the needs of large-scale hydrogen combustion and explosion simulation,a method is presented to establish single-step chemistry model and transport model for fuel-air mixture.If the reaction formula for hydrogen-air mixture is H2+0.5O2→H2O,the reaction rate model is ?? =1.13×10?5[H2][O2]exp(?46.37T0/T) mol(cm3 s)?1,and the transport coefficient model is ?=K/CP=ρD=7.0×10?5T 0.7 g(cm s)?1.By using current models and the reference model to simulate steady Zeldovich-von Neumann-Doering(ZND) wave and free-propagating laminar flame,it is found that the results are well agreeable.Additionally,deflagration-to-detonation transition in an obstructed channel was also simulated.The numerical results are also well consistent with the experimental results.These provide a reasonable proof for current method and new models.展开更多
文摘The pressure and deflagration to detonation transition(DDT)characteristics of acetylene and oxygen flame were studied in a detonation tube.The pressure history and the flame velocity along the tube were measured with high frequency pressure transducers and ion probes.By analyzing the data recorded in the experiment,the detonation wave pressure,post wave pressure and DDT distance were obtained,together with the effects of the initial pressure varying from 2×10^(4)Pa to 10^(5)Pa,equivalence ration from 0.3 to 1.0,and mixture concentration from 60%to 100%.It was found that the detonation pressure was decreased respectively with the decrease of initial pressure,equivalence ratio and mixture concentration,but the DDT distance was enlarged.The DDT distance was found particularly sensitive to mixture concentration.
基金supported by EU IIF-FP7 Project (Grant No. 909658)the National Natural Science Foundation of China (Grant No.50806071)the Fundamental Research Funds for the Central Universities of China
文摘To satisfy the needs of large-scale hydrogen combustion and explosion simulation,a method is presented to establish single-step chemistry model and transport model for fuel-air mixture.If the reaction formula for hydrogen-air mixture is H2+0.5O2→H2O,the reaction rate model is ?? =1.13×10?5[H2][O2]exp(?46.37T0/T) mol(cm3 s)?1,and the transport coefficient model is ?=K/CP=ρD=7.0×10?5T 0.7 g(cm s)?1.By using current models and the reference model to simulate steady Zeldovich-von Neumann-Doering(ZND) wave and free-propagating laminar flame,it is found that the results are well agreeable.Additionally,deflagration-to-detonation transition in an obstructed channel was also simulated.The numerical results are also well consistent with the experimental results.These provide a reasonable proof for current method and new models.
