Heat Exchangers for An Air‐Turbo‐Ram‐Jet Engine
Heat Exchangers for An Air‐Turbo‐Ram‐Jet Engine
复制标题
空气涡轮冲压喷气发动机的热交换器
DOI：
10.1002/3527605622.ch121
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
M. Ichikawa
中科院分区：
文献类型：
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作者：
H. Hatta;K. Goto;Y. Kogo;M. Ichikawa
碳/碳(C/C)复合材料是一种极具吸引力的材料，因为它们在2000°C以上的高温下具有优异的比强度和比弹性模量[1-3]。鉴于这些优点，人们试图将C/C复合材料应用于高温结构，如航天器、高超声速飞机或聚变反应堆等[1-7]。然而，由于C/C复合材料抗高温氧化能力较弱，很少应用于承载能力要求较高的初级结构中。因此，提高C/C复合材料的抗氧化性能一直是C/C复合材料的主要研究课题。因此，通过结合碳化硅涂层和玻璃裂缝密封剂，现在可以保证可靠的短期氧化保护数小时和高达1500°C，但长期和耐高温仍在积极研究中[4，8]。除了这一严重缺陷外，关于C/C复合材料在承载结构中的应用，几乎没有可靠的机械设计数据[1-4]。尽管存在上述困难，但由于材料的高温性能，作者一直在开发C/C复合材料在未来航天器发动机ATREX的涡轮盘和换热器中的应用[13，14]。ATREX发动机是一种具有膨胀机循环的空气涡轮冲压喷气式发动机，日本空间与宇航科学研究所已经研究了大约10年。该发动机被认为是两级入轨航天飞机第一级发动机的合适候选者。它是一种联合循环发动机，在亚音速到马赫2飞行时表现为涡轮喷气发动机，在马赫2到6马赫时表现为风扇增压冲压发动机。图1显示了正在开发的ATREX发动机的示意图，其主要特点包括使用氢燃料，采用膨胀机循环来提高高速性能，以及采用高温复合材料，特别是C/C复合材料。采用C/C复合材料的涡轮盘、换热器和塞式喷管正在研制中，本文报道了与这些换热器相关的研究。
Carbon‐carbon (C/C) composites are attractive materials because of their superior specific strength and specific elastic modulus at elevated temperatures over 2000°C [1‐3]. In light of these advantages, attempts have been made to apply C/C composites to high temperature structures such as space vehicles, hypersonic airplanes, or fusion reactors etc [1‐7]. However, C/C composites have seldom been applied to primary structures requiring high load bearing capability, mainly due to the composite's weakness against high temperature oxidation. Thus the improvement of oxidation resistance has been a primary research topic for C/C composites [1‐4,8‐12]. As a result, reliable short term oxidation protection for several hours, and up to about 1500°C is now guaranteed by the combination of a SiC coating and glass crack sealant, but long term and high temperature resistance is still under active study [4,8]. In addition to this serious shortcoming, few reliable mechanical design data are available regarding applications of C/C composites in load bearing structures [1‐4].In spite of the above difficulties, owing to material's performance at high temperatures, the authors have been making developing applications of C/C composites in a turbine disk and heat exchangers which are to be used for a future spacecraft engine, the ATREX [13, 14]. The ATREX engine, an air‐turbo‐ram‐jet with an expander cycle, has been studied about 10 years at the Institute of Space and Astronautical Science (Japan). This engine is regarded as a suitable candidate for the 1st stage engine of a two‐stage‐to‐orbit, TSTO, space plane. It is a combined cycle engine performing like a turbojet at subsonic to Mach 2 flight and a fan‐boost ramjet at speeds of Mach 2 to 6. Figure 1 shows a schematic diagram of the ATREX engine under development, its main features including the utilization of hydrogen fuel, an expander cycle adopted to improve high speed capability, and the employment of high temperature composites, especially C/C composites. The turbine disk, heat exchangers, and plug nozzle are now under development using C/C composites and the study related to the heat exchangers is reported in the present paper.