波瓣结构后可变面积涵道引射器掺混特性

Numerical simulation of mixing characteristic of rear variable area bypass injector with lobed structure

为进一步提升变循环发动机后可变面积后涵道引射器(RVABI)内外涵道间气流的掺混效率,改善掺混气流间的速度均匀度,提出了一种带波瓣结构的可变面积涵道引射器外涵面积调节方法,并通过数值模拟手段与两种基本模型在总压损失、热混合效率、速度分布和漩涡演化等不同方面进行分析对比。结果表明:引入波瓣结构的可变面积涵道引射器外涵面积调节方法,显著改善了流场速度均匀度,极大地提升了内外涵气流混合的热混合效率。且随着涵道比增加,相比于基准构型带,波瓣结构的面积调节方法的流向涡强度逐渐增大,热混合效率提升得更加明显,掺混的程度取决于流向涡的尺度和影响范围,可以进一步优化波瓣和对应的面积调节机构进一步提升调节性能。

In order to improve the mixing efficiency of the air flow between the inner and outer bypasses of the rear variable area bypass injector(RVABI) in the variable cycle engine,and to improve the velocity uniformity between the mixed air flows,a method of adjusting the outer bypass area of the RVABI with lobed structure was proposed.By means of numerical simulation,the total pressure loss,thermal mixing efficiency,velocity distribution and vortex evolution were studied and analyzed,and the two reference models were compared.The results showed that the method of adjusting the outer bypass area of the variable area bypass injector by introducing the lobed structure can significantly improve the uniformity of the flow field velocity and greatly improve the thermal mixing efficiency of the inner and outer bypasses.And with the increase of the bypass ratio,compared with the reference configuration band,the thermal mixing efficiency of the area adjustment method of the lobed structure was improved more significantly.The mixing degree depended on the scale and influence range of the flow vortex;the lobed shape and corresponding area can be optimized synchronously to further improve the regulating performance.