Development Study of High-response Hydrogen Concentration Probe for Supersonic Flows

超声速流高响应氢气浓度探头的研制

• 批准号: 12450390
• 负责人: NAGATA Harunori
• 金额: $ 4.61万
• 依托单位: HOKKAIDO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12450390/
• 关键词: Scramjet Engine; Supersonic Combustion; Mixing in Share Layer; Catalytic Reaction

Scramjet engine is a strong candidate for use as thrusters for space planes and supersonic civil transporter in the next generation. Supersonic mixing is a key challenge to in realizing scramjet engines. Regarding this, the main purpose of this research is to develop a simple method to evaluate hydrogen concentration in a supersonic mixing layer without the need for costly apparatus. The investigators have proposed a hydrogen concentration probe using catalytic reaction on Pt wire surface. To use this probe to detect a concentration change in a supersonic mixing layer, the response of the catalytic heat release rate must depend only on concentration change around the probe. Catalytic heat release rate on the Pt wire surface in unsteady state is measured using a constant temperature type hotwire anemometer technique and a shock tube to investigate the relation of the response of the catalytic heat release rate and Pt wire temperature. The increasing rate of the catalytic heat release depends on the Pt wire temperature when the wire temperature is low. However, the dependence is very weak when the wire temperature is over about 680 K. This shows that not the catalytic reaction but moleculartransfer from the flow to the Pt wire surface is the controlling step when Pt wire temperature is high enough. As a conclusion, catalytic reaction rate on the Pt wire is high enough comparing with the molecular transfer rate with the temperature over about 680 K, yielding high response frequency as hotwire anemometers(over a hundred kHz).

Scramjet Engine是下一代的太空飞机和超音速民用运输商的推进器的强大候选人。超音速混合是实现Scramjet引擎的关键挑战。关于这一点，这项研究的主要目的是开发一种简单的方法来评估超音速混合层中的氢浓度，而无需昂贵的设备。研究人员提出了使用PT线表面上的催化反应进行氢浓度探针。要使用此探针检测超音速混合层中的浓度变化，催化热率的响应必须仅取决于探针周围的浓度变化。使用恒定温度类型的热丝风速计技术和冲击管来测量PT线表面上的催化热率，以研究催化热释放速率和PT电线温度的响应的关系。当电线温度较低时，催化热释放的速率增加取决于PT电线温度。但是，当电线温度高于约680 K时，依赖性非常弱。这表明，当PT电线温度足够高时，从流到PT电线表面的分子转移而不是分子转移。总而言之，PT线上的催化反应速率与分子转移速率与温度的分子转移速率相比足够高，而温度在约680 K上，产生了高响应频率，作为热丝动态计（超过一百kHz）。