Test Gas Vitiation Effects in a Dual-Mode Scramjet Combustor
Test Gas Vitiation Effects in a Dual-Mode Scramjet Combustor
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DOI：
10.2514/1.24663
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发表时间：
2007-05
影响因子：
1.9
通讯作者：
C. Goyne;J. McDaniel;R. Krauss;W. B. Whitehurst
中科院分区：
文献类型：
--
作者：
C. Goyne;J. McDaniel;R. Krauss;W. B. Whitehurst
试验研究了燃烧空气预热器对超燃冲压发动机燃烧过程中主要挥发物(H2O和CO2)的影响。这些物种被添加到由电加热设施提供的最初清洁的气流中。在干燥空气中，超燃冲压发动机燃烧室在超音速模式下工作，当量比在0.25-0.32范围内工作，并在当量比0.35-0.37范围内转变为双模式。当当量比为0.27时，燃烧室在超音速模式下运行：1)干燥空气，2)空气中含有5%H2O(摩尔分数)，3)空气中含有5%H2O和2.5%CO2(摩尔分数)。在第二种情况下，燃烧室压力分布相对于干燥空气降低了10%，在第三种情况下，又测量到了2%的下降。在当量比为0.35时，燃烧室在干空气双模式下运行，而在超音速模式下仅在7%H2O下工作，这是首次证明了仅由试验气体污染引起的模式转变。因此，在从失效的地面试验推算到飞行时，重要的是要考虑到这种影响。
An experimental study was conducted to characterize the influence of combustion air preheater major vitiate species (H 2 O and CO 2 ) on scramjet combustion. These species were added to an initially clean airflow that was supplied by an electrically heated facility. With dry air, the scramjet combustor operated in the supersonic mode at an equivalence ratio in the range of 0.25-0.32 and transitioned to dual mode over an equivalence ratio range of 0.35-0.37. At an equivalence ratio of 0.27, the combustor operated in the supersonic mode for three cases: 1) dry air, 2) air vitiated with 5% H 2 O by mole, and 3) air vitiated with 5% H 2 O and 2.5% CO 2 by mole. In the second case, the combustor pressure distribution decreased 10% relative to dry air and, in the third case, another 2% decrease was measured. At an equivalence ratio of 0.35, the combustor operated in the dual mode with dry air, but in the supersonic mode with 7 % H 2 O. This is the first demonstration of mode transition solely caused by test gas vitiation. It is therefore important to account for such effects when extrapolating from vitiated ground testing to flight.