进气道出口截面形式对补燃室掺混性能的影响研究

Effects of Cross Section of Inlet Exit on Mixing Performance of Afterburner

关键词:  固体火箭冲压发动机  补燃室  进气道  掺混  气动特性  燃烧效率

Key words:  Solid rocket ramjet  Afterburning chamber  Inlet  Mixing  Aerodynamic characteristics  Combustion efficiency

摘要:

为研究进气道出口截面形式对补燃室掺混气动特性和燃烧性能的影响，对双下侧布局形式的固冲发动机内流场进行数值模拟，对比分析了补燃室相同压比下，进气道矩形出口截面和圆形出口截面在不考虑燃气的混合和反应时掺混段的气动特性和考虑燃气反应时补燃室的燃烧性能。结果表明：两股空气掺混过程中，研究的两种进气道出口截面方案的整体总压损失大致相同，但进气道圆形出口截面的掺混段内流线表现为不稳定的螺旋点形态，相比于方形出口截面的掺混段，其使气流掺混更剧烈，短距离内掺混已经很均匀，且旋流强度小；在考虑燃烧时，进气道圆形出口截面对应的补燃室出口总压恢复系数比方形截面的高约2%，方形进气道出口截面的补燃室出口截面总燃烧效率为95.58%，而圆形截面的达到99.86%。

Abstract:

In order to study the effects of the cross section of the inlet exit on the mixing aerodynamic characteristics and combustion performance on afterburner， the internal flow field of solid rocket ramjet mixing section with twin-inlet 90° configuration at Venter was numerically simulated. The afterburner performance of circular and rectangular inlet exit sections without/with considering the mixing and reaction of gas were compared and analyzed under the same pressure ratio of the afterburning chamber. The results show that in the mixing process of air， the total pressure loss of the two types of inlet exit section is roughly the same. However， because the streamline in the mixing section of circular inlet exit section presents an unstable spiral point form， the mixing of circular inlet exit section is more uniform in a short distance， and the swirling intensity is smaller than that of rectangular inlet exit section. When the combustion reaction is considered， the total pressure recovery coefficient of afterburner with the circular section of inlet exit is about 2% higher than that of the rectangular section. The total combustion efficiency of afterburner with the rectangular section of inlet exit is 95.58%， while that of the circular section is 99.86%.