A numerical study on the influence of increased instability of quasi-detonation on the critical tube diameter phenomenon

At critical conditions, the effect of instability plays a prominent role in gaseous detonation transmission from tube into an unconfined space. This study aims to clarify such by investigating diameter quasi-detonations, i.e., detonations under influence minor perturbations along walls. The strategy is conduct two-dimensional numerical simulations using reactive Euler equations with two-step induction-reaction kinetic model. chemical parameters were adapted model wave stoichiometric hydrogen-oxygen mixture at 20 kPa and 300 K. quasi-detonations are obtained channels obstacles (attached boundaries) different sizes mimic wall roughness, ?, which defined as ratio between obstacle size ? half channel width D1/2. Below value rough creates only intrinsic cellular detonation. Apart velocity deficit, degree irregularity increases resulting broader spectrum probability density function pressure induction rate. For ?? 0.24, propagation dynamics more significantly altered—the structure vanishes locally or small cells re-appear new re-initiation points. Detonations these obstructed not considered subjected boundary perturbations. values roughness on phenomenon then examined. A shot-to-shot variation performing multiple for each assess successful quasi-detonation diffraction sub-critical condition, despite increasingly higher instabilities rough-walled geometry promote open area. However, if beyond both deficit modes lead lower transmission.