Shockwaves generated in micro tubes without diaphragms:investigation of shock waves and subsequent flows that are generated with high speed valves or ultrashort laser pulses and that are propagating in fluids within micro tubes

虽然冲击波的物理学及其应用在宏观领域得到了很好的研究，但对于微观领域却并非如此（宏观：直径大于1 mm至远大于1 m的激波管;微观：直径小于1 mm至10微米（或更小）的管或微通道）。几年前，第一次在微观尺度上进行的冲击波实验在冲击波物理学中开辟了一个新的领域。然而，只有这几个实验。然而，很明显，适用于宏观制度的理论通常不适合（或仅部分适合）微观制度。因此，理论必须修正。此外，一系列新的问题变得重要。尽管在社会上有很大的兴趣，作为一个罕见的可用的调查结果，在微观尺度上的冲击波物理学可以被认为是仍然处于起步阶段。这直接导致了该项目的动机和目标：这是为了获得对微管中冲击波的发生和传播的基本物理理解（包括细节）。值得一提的是，除了基本的重要性之外，这也将对应用感兴趣，即使它们不是项目中的直接目标（在医学或生物学中的可能应用是无针疫苗输送或将有机材料转移到细胞中;此外，微流体中有很多应用）。实际上，在该项目中，它旨在用短激光脉冲（LIMS方法）或高速电磁阀产生微冲击波。冲击波将在填充有气体（将施加不同的压力）、蒸汽或液体作为流体的微通道中产生。流体参数和状态的变化将通过光学方法（主要）和高的时间和空间分辨率进行非接触式研究。特别感兴趣的是壁摩擦和热传导的影响，冲击波的发生，传播和衰减以及接触表面的影响。激波前缘曲率、超音速流的湍流和层流状态之间的过渡也是令人感兴趣的，“理想”碰撞激波的实验以及用于产生激波的激光脉冲序列的应用也是令人感兴趣的。最后，它的目的是确定是否冲击波的产生，传播和检测是可能的显着较小的管之前。所获得的结果将为微流控、纳米技术、医学物理等领域的应用奠定重要的物理基础。

Although physics of shock waves and its applications are well investigated in the macroscopic regime, this is not true for the micro regime (macroscopic: shock tubes with a diameter larger than 1 mm up to much more than 1 m; microscopic: tubes or micro channels with a diameter below 1 mm down to 10 micron (or less)). A few years ago, first experiments with shock waves on micro scale opened a new field within physics of shock waves. However, there are only those few experiments. Nevertheless, it has become clear that the theory that is applied for the macro regime, is not generally suitable (or only partly) for the micro regime. Consequently theory must be revised. Moreover, a series of new questions has become important. Even though there is large interest in the community, as a result of the rare available investigations, physics of shock waves on micro scale may be regarded to be still at the beginning. This directly leads to the motivation for the project and it’s goal: this is to obtain a basic physical understanding of the onset and the propagation of shock waves in micro tubes (including details). It may be mentioned that beside the fundamental importance, this will also be of interest for applications, even though they are not direct objectives within the project (possible applications in medicine or biology are needleless vaccine delivery or the transfer of organic materials into cells; in addition, there is a lot of applications within micro fluidics). Actually, within the project it is intended to generate micro shock waves either with a short laser pulse (LIMS method) or with a high speed magnetic valve. The shock waves will be generated in micro channels filled with gases (different pressures will be applied), vapors or liquids as the fluid. The fluid parameters and the changes of state will be investigated contactless by means of optical methods (mostly) and with high temporal and spatial resolution. Of special interest is the influence of wall friction and heat conduction, the onset, propagation and attenuation of the shock waves and the influence of the contact surface. The shock front curvature, the transition between the turbulent and the laminar regime of the supersonic flow are of interest as well and also experiments with “ideal” colliding shock waves and the application of a laser pulse train for shock wave generation. Finally, it is intended to determine if shock wave generation, propagation and detection is possible in significant smaller tubes as before. The acquired results will built an important physical fundament for applications such as micro fluidics, nano technology, medical physics and many other interesting topics.