A Study on Flame-Holding and Ignition of Hydrocarbon Fuel in Supersonic Flow

碳氢燃料在超音速流动中的保焰与点火研究

基本信息

批准号：
15560685
负责人：
WAKAI Kazunori
金额：
$ 2.24万
依托单位：
Gifu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2005
项目状态：
已结题

项目摘要

Hydrocarbon fuel is attractive for scramjet engine because of its high energy density. However, its low reactivity is pointed out as a large demerit. In order to use hydrocarbon fuel for a scramjet combustor, it is important to ensure ignition and flame-holding in a supersonic airflow. In this research, we use kerosene as a fuel and inject it into a scramjet combustor with a cavity, which is L in length and D in depth. The Mach number is 2 and the total temperature is 1800K-2400K. We also conduct numerical simulations as well as wind tunnel experiments. From the experimental result, it is found that there is a certain combination of L and D that leads to the maximum improvement of flame-holding performance. The numerical result shows that in a such case, large and complex vortex structure is generated in the cavity and prolong the residence time of the fuel in the combustor. On the other hand, it is predicted that the temperature in the cavity increases due to the decrease of the incoming flow. However, it is difficult to measure the temperature with intrusive method, such as a thermocouple. Hence, we adopt the two-band emission method instead with H2O as a target particle. We can measure the temperature in the cavity without disturbing the flow filed. The measured temperature was compared with the predicted one and they agree well. It is found that the well-designed cavity has good performance for flame-holding of hydrocarbon fuel in supersonic flow by prolonging the residence time and increasing the temperature.

由于其高能密度，碳氢化合物燃料对Scramjet发动机具有吸引力。但是，其低反应性被指出为较大的缺点。为了将碳氢化合物燃料用于Scramjet燃烧器，重要的是要确保在超音速气流中点火和火焰。在这项研究中，我们将煤油用作燃料，并将其注入带有腔体的Scramjet燃烧器，该腔内长度为1，深度为D。马赫数为2，总温度为1800k-2400k。我们还进行数值模拟以及风洞实验。从实验结果中可以发现，L和D的某种组合可以最大程度地提高火焰持续性能。数值结果表明，在这种情况下，在腔体中产生了大而复杂的涡旋结构，并延长了燃烧器中燃料的停留时间。另一方面，可以预测，由于输入流的降低，腔中的温度升高。但是，很难用侵入性方法（例如热电偶）测量温度。因此，我们采用两波段发射方法，而将H2O作为目标粒子。我们可以测量腔中的温度，而不会干扰提交的流量。将测得的温度与预测的温度进行了比较，它们一致。发现精心设计的腔具有良好的性能，可通过延长停留时间并升高温度，可在超音速流中烃燃料的火焰持续。