富氢燃气旋转爆轰波传播特性实验研究

Experimental Study on Propagation Characteristics of Rotating Detonation Wave of Hydrogen-Rich Gas

关键词:  富氢燃气  旋转爆轰  当量比  传播模态  时频特性

Key words:  Hydrogen-rich gas  Rotating detonation  Equivalence ratio  Propagation mode  Time-frequency characteristics

摘要:

为研究富氢燃气旋转爆轰波传播特性，利用氢气与氧气预燃烧产生的富氢燃气作为燃料，空气为氧化剂，开展了旋转爆轰实验研究。对富氢燃气旋转爆轰压力变化、时频特性及传播速度等参数进行了分析，研究了不同传播模态下富氢燃气旋转爆轰波传播特性。研究表明：本文实验条件下，富氢燃气与空气旋转爆轰的传播模态主要受当量比影响，当量比高于1.06时呈现单波模态，随着当量比减小，旋转爆轰波呈现单波-双波过渡模态，即同一工况下，单波模态和双波模态交替出现，当量比减小到0.68左右时，基本呈现复杂的双波模态；在270g/s的空气流量下，当量比增大，旋转爆轰波在环形燃烧室内的传播速度随之提高，但当量比到达临界点以后，传播速度提高不明显；在相同当量比下，当空气流量增大到370g/s时，旋转爆轰波的传播速度会进一步提高；空气流量越大，临界点对应的当量比越低，其中270g/s空气流量对应临界当量比为1.32，370g/s空气流量对应临界当量比1.16；达到临界当量比以后，传播速度受当量比和空气流量影响不大。

Abstract:

In order to investigate the propagation characteristics of rotating detonation wave （RDW） of hydrogen-rich gas， the experimental study of rotating detonation was carried out by using hydrogen-rich gas as fuel and air as oxidant. Hydrogen-rich gas was produced by pre-combustion of hydrogen and oxygen. The variation of rotating detonation pressure， time-frequency characteristics and propagation velocity of RDW were analyzed， and the propagation characteristics of RDW of hydrogen-rich gas under different propagation modes were studied. The results show that under the experimental conditions， the propagation mode of hydrogen rich gas and air rotating detonation is mainly affected by the equivalence ratio. When the equivalence ratio is higher than 1.06， the RDW presents a single wave mode. With the decrease of equivalence ratio， the RDW presents the transition mode from single wave to two waves， that is， under the same working condition， the single wave mode and two waves mode appear alternately. When the equivalence ratio decreases to about 0.68， the RDW basically presents a complex two wave mode. At the air mass flow rate of 270g/s， the propagation velocity of RDW in annular combustion chamber increases with the increase of equivalence ratio， but the propagation velocity of RDW does not increase significantly after the equivalence ratio reaches the critical point. At the same equivalence ratio， when the air mass flow rate increases to 370g/s， the propagation velocity of RDW will be further improved. Moreover， the larger the air mass flow， the lower the equivalence ratio corresponding to the critical point. When the air mass flow rate is 270g/s， the critical equivalence ratio is 1.32， and when the air mass flow rate is 370g/s， the critical equivalence ratio is 1.16. After reaching the critical equivalence ratio， the propagation velocity is not affected by the equivalence ratio and air mass flow.