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纳秒脉冲介质阻挡放电等离子体对超声速燃烧室中凹腔性能的影响 总被引:2,自引:0,他引:2
为考察纳秒脉冲介质阻挡放电(NP-DBD)等离子体对超声速燃烧室中凹腔性能的影响,在凹腔后壁面上部区域布置表面介质阻挡放电激励器产生等离子体,基于NP-DBD等离子体高斯分布热源模型,采用3维数值模拟方法研究了等离子体作用下燃烧室壁面压力、凹腔阻力、质量交换率以及燃料分布的变化。研究结果表明,NP-DBD等离子体虽然降低了对称面处凹腔后缘波系强度,但结合凹腔后壁区域温度分布特征知等离子体热效应较弱,故整个凹腔波系受到影响较小;凹腔质量交换能力获得大幅提高,其阻力则略有减小;等离子体缩小了凹腔上方燃料的分布范围,凹腔下游燃料掺混效率有小幅提升。 相似文献
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J. L. Le H. C. Bai A. A. Mishunin A. V. Starov 《Combustion, Explosion, and Shock Waves》2003,39(3):292-299
Results of an experimental study of a full scramjet model operating on kerosene, which was performed in an IT-302M hotshot wind tunnel based at the Institute of Theoretical and Applied Mechanics of the Siberian Division of the Russian Academy of Sciences, and an experimental study of a model operating on hydrogen, which was performed in a hotshot wind tunnel with fire heating based at the China Aerodynamic Research and Development Center, are reported. The tests were performed for Mach numbers 5 and 6 for flow parameters close to in-flight conditions. An optimal system for kerosene injection under these conditions was determined, and the thrust characteristics of the engine model were examined. The possibility of controlling kerosene combustion in tests in the short-duration wind tunnel was analyzed, and special features of fuel ignition in a short combustor were considered. Intense combustion of kerosene was achieved with upstream injection of more than 3% of hydrogen, which allowed obtaining effective thrust. The distributions of static pressure and force characteristics of the model in the case of kerosene and hydrogen combustion were compared. 相似文献
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涡旋燃烧炉是最近研制的一种新型固体燃料旋风燃烧炉,它采用了多级切向进风的结构。本文应用气固两相流的多连续介质模型及其数值计算方法,针对分级供入炉内的空气采用正反切向进风的条件,对涡旋燃烧炉内的气固两相湍流旋流流动进行了数值模拟。通过模拟结果的分析及其与分级同向切向进风情况的比较,探讨了在涡旋燃烧炉中采用多级正反切向进风方式的可能性。 相似文献
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美国Forney公司火焰检测器及其应用 总被引:2,自引:0,他引:2
为防止炉膛爆炸,大容量机组的锅炉均装设锅炉灭火保护装置,但是如何选用安全可靠的火焰检测装置,将直接关系到炉膛和整个机组的安全经济运行。为此,以美国Forney火焰检测系统为例,介绍它在淮北二电厂的安装、使用和维护方面的一些经验,供同行借鉴。 相似文献
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Tomiaki Furuya Kunihiko Sasaki Yoshio Hanakata Toshiyuki Ohhashi Masahiko Yamada Toshiaki Tsuchiya Yutaka Furuse 《Catalysis Today》1995,26(3-4):345-350
The hybrid catalytic combustor concept proposed by the authors has an advantage concerned with catalyst durability, because the catalyst is maintained below 1000°C even for application to 1300°C class gas turbines. A full-scale hybrid catalytic combustor has been designed for a 200 MW (1300°C) class gas turbine. The catalyst bed was 450 mm in diameter and consisted of a Pd/ alumina washcoat on a cordierite monolith. In experiments, the combustor has demonstrated the capability of meeting the NOx emission level of SCR (selected catalytic reduction) during atmospheric pressure testing. To predict the catalyst performance at an elevated pressure, the characteristics of the catalyst were studied using a small scale reactor test, and a material property test using a DTA/TGA-Q.MASS system. The catalyst showed a higher activity in the oxidized state (PdO) than in the metallic state (Pd). This activity difference was governed by the equilibrium of the oxygen release from PdO in bulk. It was considered that oxidation rate of the metallic Pd in bulk was not so high and this caused self-oscillation for the Pd catalyst around the temperature of the oxygen release equilibrium. Even below the temperature of the oxygen release equilibrium, both surface and bulk (lattice) oxygen of the PdO was consumed by the methane oxidation reaction, and resulted in a lack of surface oxygen on the catalyst. This caused a reversible decrease in the catalyst activity during combustion testing, and indicated that the oxygen dissociation step was a rate limiting step in the catalytic combustion. 相似文献