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

计划中的项目建议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，以更好地了解特定气体和单一反应机理及其在广泛温度和压力范围内的主导作用。该工作建议包括实施一种先进的方法，以实验确定等离子体风洞中产生的高焓和非平衡流动中的复合系数。此外，它还包括对数值重建的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)被用于IRS高焓等离子体风洞设施PWK3，它将被用于研究的实验部分，并结合充分选择的等离子体诊断。重点放在边界层的特征上，以增加评估气体-表面相互作用及其相关性质的置信度。为了减少实验的不确定度，提出了一种与发射率无关的确定辐射热流和壁温的技术。对于边界层的数值重建，支持和补充实验获得的气体传输参数，将使用斯图加特大学(天王星)非平衡流动的IRS迎风松弛算法。在这里，这个非凡的星座体现在这样一个事实上，即复杂气体流动的补充实验数值研究可以在同一机构进行。此外，由于模拟结果与飞行数据和等离子体风洞实验数据的成功比较，天王星的验证和验证水平得到了充分的发展。本项目正在进行的样品是碳化硅、碳化硅和5级钛Ti6Al4V，其气面相互作用特性在空间和地球应用中引起了极大的兴趣。该项目计划持续三年，分为五个工作包，这些工作包在逻辑和时间上结构了实验和数值活动。需要对现有的等离子体诊断仪进行微小但必要的升级，以实现适当的流动校准和材料特性。最终，基于飞行实验催化的传感器PHLUX将被组装并暴露在PWK3中众所周知的独立特征的流动条件下，以验证该方法。因此，将评估等离子体成分，并将其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.