摘要
为了解缓燃向爆震转捩（DDT）过程,在60 mm×60 mm,长2 m的方形爆震管内,利用高速摄影和高频压力传感器试验研究了4种余气系数下氢气/空气混合气燃烧时的火焰和压力波演变规律.结果表明：缓燃向爆震转捩经历了缓燃、爆燃、在壁面产生热点、形成爆震中心和稳定爆震5个阶段,缓燃、爆燃和爆震的火焰传播速度分别为0－15 m/s,500－1000 m/s和1800－2000 m/s.压力传感器获得的时序图和对应峰值压力的变化规律也验证了上述过程：在压力传感器测试区间（850－1200 mm）内,压力峰值从1.5 MPa先跃升到7 MPa上下,然后下降稳定在2－3 MPa.据压力时序图算得的爆震波传播速度与高速摄影获得的火焰传播速度一致.
A series of single-shot detonation experiments was performed to characterize the deflagration to detonation transition（DDT） process for H2/Air mixtures in a 60mm square tube that was 2 m in length. High speed digital imaging was used to track flame prop agation beginning from the ignition , and simultaneous seven high-speed pressure transduc ers, mounted along the tube wall between 850-1 200 mm, were used to record progress of the compression and shock wave. According to high speed images, it is found that DDT process has five phase：① Normal combustion is initiated by an electric spark and its velocity is only 0-15 m/s;② Flame acceleration and deflagration formation which propagates with 500-1 000m/s; ③Hot spots appear along the tube wall; ④ formation of explosion center which creates blast wave;⑤ formation of strong detonation wave which propagates with 1 800-2000m/s. In the zone from 850 to1200mm,which pressure transducers were mounted, the maximum pressure value firstly rises from 1.5 MPa to 7 MPa,then down to 243 MPa, and the detonation wave velocity is about 2 000-2 100 m/s, which is suit with the result a-chieved from the high speed digital imaging.
出处
《航空动力学报》
EI
CAS
CSCD
北大核心
2008年第11期2036-2042,共7页
Journal of Aerospace Power
基金
国家自然基金(50506012)
关键词
爆震
缓燃向爆震转捩
压力波和火焰
高速摄影
试验研究
detonation
deflagration to detonation transition, wave and flame
high-speed digital imagining, experimental study
