Heterogenous Gas-Wall-Interactions in high enthalpy Non-Equilibrium Flows

计划中的项目提出了在大气进入相关条件下对高温材料的复杂催化模型进行校准，以便更好地了解特定气体和单一反应机理及其在大范围温度和压力下的优势。工作建议包括实施一种先进的方法来实验确定等离子体风洞中产生的高焓和非平衡流的复合系数。此外，它还包括数值重建气体参数的实验验证和方法的验证。感应加热等离子体发生器（IPG3-5）用于IRS高焓等离子体风洞设备PWK3，该设备将用于研究的实验部分，并结合适当选择的等离子体诊断。重点放在边界层的表征上，以便增加气表面相互作用及其相关性质评估的置信度。为了减小实验的不确定性，提出了一种与发射率无关的辐射热流密度和壁面温度的测定方法。对于边界层的数值重建，支持和补充实验得到的气体输运参数，将使用斯图加特大学（URANUS）的IRS逆风松弛算法（IRS Upwind Relaxation Algorithm For Non-equilibrium flows）。在这里，不同寻常的星座可以看到，复杂气体流动的互补实验数值研究可以在同一个机构进行。此外，由于将模拟结果与等离子体风洞的飞行数据和实验数据进行了成功的比较，URANUS的验证和验证水平得到了充分的发展。碳化硅SiC和5级钛Ti6Al4V的样品正在该项目的过程中，其中气体表面相互作用特性在空间和地球应用中具有很高的兴趣。该项目计划为期三年，分为五个工作包，按逻辑和时间顺序排列实验和数值活动。为了完成适当的流量校准和材料表征，需要对现有的等离子体诊断进行小而必要的升级。最终，基于飞行实验催化的传感器PHLUX将被组装起来，并在PWK3中暴露在一个众所周知的、独立表征的流动条件下，以验证该方法。因此，将对血浆组成进行评估，并分别与其他独立测量技术的结果进行比较。

The planned project proposes the calibration of complex catalytic models for high-temperature materials in atmospheric entry relevant conditions in order to better understand gas-specific and single reaction mechanisms and their dominances at wide range of temperatures and pressures. The work proposal includes the implementation of an advanced methodology to experimentally determine recombination coefficients in high-enthalpy and non-equilibrium flows generated in plasma wind tunnels. Moreover, it includes experimental verifications for numerically reconstructed gas parameters and a validation of the methodology. Inductively heated plasma generators (IPG3-5) are I use for the IRS high-enthalpy plasma wind tunnel facility PWK3, which will be employed for the experimental part of the investigation in combination with adequately selected plasma diagnostics. An emphasis is put on the characterization of the boundary layer in order to increase the level of confidence for the assessment of the gas-surface interactions and of its relevant properties. An emissivity-independent technique for the determination of the radiative heat flux and the wall temperature is proposed in order to reduce the experimental uncertainties. For the numerical reconstruction of the boundary layer, supporting and complementing the experimentally obtained gas transport parameters, the IRS Upwind Relaxation Algorithm for Non-equilibrium flows of the University of Stuttgart (URANUS) will be used. Here, the extraordinary constellation is to be seen in the fact that complementary experimental numerical investigations of complex gas flows can be performed at one and the same institution. Moreover, the verification and validation level of URANUS is adequately well developed due to the successful comparison of simulation results with both in-flight data and experimental data from plasma wind tunnels.Samples out of silicon carbide SiC, and grade 5 titanium Ti6Al4V are in the course of this project, for which the gas-surface interaction properties are of high interest in space and earth applications.The project is planned for a three-year duration and is divided in five work packages, which logically and chronologically structure both the experimental and numerical activities. A small but essential upgrade of the existing plasma diagnostics is required in order to accomplish a proper flow calibration and material characterisation. Eventually, the flight-experiment catalysis-based sensor PHLUX will be assembled and exposed to a well-known and independently characterised flow condition in PWK3 for the validation of the methodology. The plasma composition will thus be assessed and respectively compared with results from other independent measurement techniques.