爆轰波三波点擦除烟迹表面积碳机制

Precise mechanism of triple point passage removing soot on soot-coated surface

  • 摘要: 为理解三波点在壁面及端面积碳留下记录的确切机制,推动对螺旋爆轰内部结构的研究,采用端面烟熏玻璃与内壁烟膜结合的实验方法记录胞格结构,并得到不稳定、较稳定及稳定预混气的侧壁及端面爆轰记录.2H2+O2+3Ar给出了清晰精细的端面结果,其单头螺旋结果表明相对于结果近似的侧壁结果,内部螺旋结构并非固定.进而从附着碳粒的粒度尺寸分析出碳迹附着原理并结合五种预混气的反应特性,确定键能足以克服碳迹吸附在表面的力时才能擦除烟迹.另外预混气中的碳分子也会导致烟迹堆积而影响端面结果,反射激波的强度也影响记录的清晰度.最终确定烟迹擦除机制受预混气影响,应针对预混气选用表面粗糙度载体和积碳颗粒尺寸,并给出了记录爆轰结构的方法.

     

    Abstract: To understand the precise mechanism by what the soot is removed when the triple point passed over the smoked inner wall foil or smoked end-on glass and promote the research on spinning detonation structure, smoked end-on glasses and inner wall smoked foils were established to record the trajectories of triple-shock Mach intersections of spinning detonation. Detonation records of unstable, a little stable and very stable premixed mixtures were obtained in wall foils and end-on glasses. Smoked end-on glass of 2H2 + O2 + 3Ar gave clear records. Sing-head spinning detonation records of 2H2 + O2 + 3Ar indicates that the internal structure of the spinning detonation is not stable while the inner wall results are similar. The cause why soot can be adsorbed on foils and glasses is one factor. Another factor is that reaction characteristics performance of different mixtures should be considered according to above experimental results. The soot can be removed when bond energy is bigger than adsorption energy between the soot and the foil or glass surface. What's more, the carbon molecules particles in detonation front reaction may lead to carbon accumulation and affect the records. In another hand, the strength of reflected shock wave may affect the clarity of the records. Finally, the precise mechanism is affected by characteristics of mixtures. Using appropriate surface roughness and soot particle size according to mixtures characteristics can give satisfying detonation structure records.

     

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