Investigations on Spray Characteristics and Self-Pulsation of a Gas-Centered Shear Coaxial Injector
Investigations on Spray Characteristics and Self-Pulsation of a Gas-Centered Shear Coaxial Injector
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DOI：
10.3389/fenrg.2022.887368
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发表时间：
2022-05
期刊：
影响因子：
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通讯作者：
Gao Yuchao;Chu Wei;X. Yuan;Jiang Chuanjin;Xu Boqi;Su Lingyu;Tong Yiheng
中科院分区：
文献类型：
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作者：
Gao Yuchao;Chu Wei;X. Yuan;Jiang Chuanjin;Xu Boqi;Su Lingyu;Tong Yiheng
通过实验和数值模拟，研究了气心剪切同轴喷嘴在不同工况和不同凹腔比下的喷雾特性。采用耦合水平集和流体体积法（CLSVOF）和自适应网格加密法（AMR）进行数值模拟。结果表明，在无凹槽的情况下，当液体质量流量（mstecl）保持不变时，喷雾角先基本保持不变，然后随气体质量流量（mstecg）的增加而线性下降。与此相反，与凹槽，喷雾角被发现增加与m stecg，这可能是由于中心气流的二次膨胀。在特定条件下，会发生自我脉动，并伴随着一声尖叫。自脉动的频率随着m stecg和m stecl的增加而增加。自搏频率随RR的增加而降低。同时，通过数值模拟对自脉动的机理进行了初步探讨。结果表明，自脉动是由液膜内外的表面张力和压差以及中心气流的冲击挤压作用共同作用而产生的。
The spray characteristics of a gas-centered shear coaxial injector under different conditions and recess ratios (RR) were studied through experiments and numerical simulations. The numerical study was carried out based on the coupled level set and volume-of-fluid (CLSVOF) method and the adaptive mesh refinement (AMR) method. The results indicated that without recess, the spray angle first stayed almost constant and then dropped linearly with an increase in the gas mass flow rate ( m ˙ g ) when holding the liquid mass flow rate ( m ˙ l ) constant. In contrast, with recess, the spray angle was found to increase with m ˙ g , which could be attributed to the secondary expansion of the central gas flow. Under specific conditions, self-pulsation occurred and was accompanied by a loud scream. The frequency of the self-pulsation increased with both m ˙ g and m ˙ l . Moreover, the self-pulsation frequency decreased with RR. Meanwhile, the mechanism of self-pulsation was initially explored through numerical simulation. It was concluded that self-pulsation was caused by the surface tension and the pressure difference between the inside and outside of the liquid sheet, together with the central airflow impact extrusion.