Retropropulsion, a deceleration technique where the thrust is directed along the flight path, is the driving technology for vertically landing, reusable launchers. Experiments, which are indispensable for the full comprehension of retropropulsion flows, pose serious challenges to the operability of wind tunnels and interpretation of these subscale experiments. The key factors to facilitate meaningful results of supersonic and hypersonic retropropulsion experiments are addressed in this study. Similarity parameters for subscale experiments are evaluated, the interaction of retropropulsion flows with the test facility is investigated, and condensation within these flows is analyzed. For this purpose, computational fluid dynamics simulations were performed; subsequently, cold gas experiments for a generic retropropulsion launcher configuration with a single central nozzle were carried out in the hypersonic wind tunnel Cologne H2K at the Supersonic and Hypersonic Technologies Department of the DLR, German Aerospace Center. Based on these data, an improved similarity parameter related to the exit condition of the engine exhaust flow is proposed, and a universally applicable scaling law for supersonic retropropulsion wind-tunnel models is derived and validated. Various condensation mitigation techniques for the conducted experiments are presented, and their varying effectiveness is highlighted.

逆行推进是一种推力沿着飞行路径定向的减速技术，是垂直着陆，可重复使用的发射器的驱动技术。对于全面理解后向推进流必不可少的实验，对风洞的可操作性和这些规模实验的解释提出了严峻的挑战。这项研究探讨了促进超音速和高超音速后向推进实验有意义结果的关键因素。评估了小规模实验的相似性参数，研究了反推进流与测试设备之间的相互作用，并分析了这些流中的冷凝水。为此，进行了计算流体动力学模拟。随后，在德国航空航天中心DLR的超音速和超音速技术部的高音速风洞Cologne H2K中，对具有单个中央喷嘴的通用反推进发射器配置进行了冷气实验。基于这些数据，提出了一种改进的与发动机排气流出口状况相关的相似性参数，并推导并验证了超音速逆向推进风洞模型的通用定标律。介绍了用于进行的实验的各种缩合缓解技术，并突出了它们的不同有效性。提出了一种改进的与发动机排气出口状态相关的相似性参数，并推导并验证了超声速推进风洞模型的通用定标律。介绍了用于进行的实验的各种缩合缓解技术，并突出了它们的不同有效性。提出了一种改进的与发动机排气出口状态相关的相似性参数，推导并验证了超声速反风洞模型的通用定标律。介绍了用于进行的实验的各种缩合缓解技术，并突出了它们的不同有效性。