Fast combustion at microscales - Combustion rapide aux micro-échelles

目的：拟议的研究计划旨在研究毫米和亚毫米尺度上带有化学热释放的非定常可压缩流动现象的产生和传播。基于这些发现，我们将在高功率密度微系统领域寻求一些生物医学和航空航天应用。科学方法：我们的方法是基于使用专门建造的设备在小范围内对可压缩流动现象进行实验观察，并开发简单的分析模型来解释实验观察结果。然后，我们利用这一新知识来开发利用这些现象的新型设备。我们在微米级通道中冲击波的实验研究中发展了独特的专业知识，我们将利用这种能力来研究那些尺度下的预混合气体混合物中的燃烧波。特别是，我们将研究是否可以使用适当的初始条件(特别是增压)和点火技术将通常的燃烧标度定律和传播区域扩展到亚毫米级。如果成功，这些燃烧波将用于原始的小型化推进和驱动系统。新奇和意义：各种MEMS器件(发动机、燃料电池等)的连续微燃烧引起了极大的兴趣。但很少有研究在小尺度上研究非稳定燃烧波的传播，而且从未在我们独特的实验设备的微米尺度上进行过研究。因此，这应该会产生有价值的新知识，这些知识可能会在设计新型高功率密度微系统时被利用。

Objectives: The proposed research program aims at studying the generation and propagation of unsteady compressible flow phenomena, with chemical heat release, at millimeter and sub-millimeter scales. Based on these findings, a number of biomedical and aerospace applications will be pursued in the area of high-power density microsystems.Scientific approach: Our approach is based on the experimental observation of compressible flow phenomena at small scale using specially-built devices and on developing simple analytical models to explain the experimental observations. We then use this new knowledge to develop novel devices exploiting these phenomena.We have developed a unique expertise in the experimental investigation of shock waves in micron-scale channels and we will leverage this capability in the study of combustion waves in pre-mixed gaseous mixtures at those scales. In particular, we will investigate if the usual combustion scaling laws and propagation regimes can be extended down to the sub-millimeter scale using appropriate initial conditions (especially elevated pressure) and ignition techniques. If successful, these combustion waves will be used in original miniaturized propulsion and actuation systems.Novelty and significance: There is great interest in continuous micro-combustion for various MEMS devices (engines, fuel cells, etc.) but only few studies have investigated the propagation of unsteady combustion waves at small scales, and never at the micrometer scale of our unique experimental facilities. So this should produce valuable new knowledge that can potentially be exploited in the design of novel high-power density microsystems.