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为研究飞行马赫数Maflight=4～7的双燃室碳氢燃料超燃冲压发动机燃烧室的原理和工程参数,进行了直连双燃室超声速冷主流和亚燃室稳焰火炬热流的掺混实验和燃烧实验。将进气道输出的超声速气流的10%流量经亚燃进气道导入亚声速预燃室,先低速地与雾化预燃油掺混并建立稳定的预燃。该预燃气流与二次喷入的主燃油掺混而形成富含吸热分解油气的高温射流,再经一组波瓣掺混器与超声速主流在下游流向涡中深入掺混/燃烧,扩大燃区厚度而趋于深入超声流层,以期实现稳定超燃。在总温约为285K、总压为1.5×106 Pa和1.0×1.06 Pa,燃烧室进口马赫数Mainlet=2.5的来流下,对3种不同结构参数的预燃室和一种超燃室,进行了冷态流场和预燃/主燃的喷油/燃烧实验。实验与计算结果表明,冷/热态实验中整个超燃室保持了超声速流动,尽管斜激波系存在一些变化。利用存在的4种旋涡掺混现象,增强超/亚声速流之间的掺混。当采用三波系进气道和较小容积热强度的大体积预燃室和流向涡掺混器,可以形成稳定的高温富油火炬,成为超燃室稳定点火源。在超燃室下层流层的原无预热冷态来流的亚声速和低超声速区域中出现火焰,且其并不破坏超燃室上层的高超声速未燃流动。
In order to study the principle and engineering parameters of a two-chamber HCFC combustion engine with a flight Mach number of Maflight = 4 ~ 7, a direct-coupled dual-chamber supersonic mainstream cooling and a sub-combustion stable flame torch heat flow mixing Experiment and burning experiment. 10% of the supersonic flow output from the inlet will be introduced into the subsonic chamber via the sub-combustion inlet, then mixed with the atomized pre-fuel at a low speed to establish a stable pre-combustion. The pre-combustion gas stream is mixed with the secondary fuel injected into the main fuel to form a high-temperature jet rich in endothermic decomposition oil, which is further mixed / burned in the downstream flow vortex by a set of lobe blenders and the supersonic mainstream, expanding The thickness of the combustion zone tends to be deeper into the supersonic laminar flow in order to achieve stable combustion. Under the conditions of a total temperature of about 285 K, a total pressure of 1.5 × 10 6 Pa and 1.0 × 1.06 Pa, and an inlet flow rate of Mainlet = 2.5 at the inlet of the combustion chamber, three kinds of preburners and one type of an explosion chamber with different structural parameters were subjected to Cold flow field and pre-combustion / main fuel injection / combustion experiments. The experimental and computational results show that the supersonic chamber maintains the supersonic flow in the cold / hot experiment, although there are some variations in the oblique shock system. Blending between super / sub-sonic streams is enhanced by the presence of four vortex mixing phenomena. When a large volume pre-chamber and a flow vortex mixer with three-wave inlet and smaller volumetric heat intensity are used, a stable high-temperature oil-rich torch can be formed and a stable ignition source for the super-combustion chamber can be formed. Flames were found in the subsonic and low-supersonic regions of the preheat-free cold flow of the lower laminar stratosphere, and did not destroy the hypersonic unburned flow in the upper strata.