TARES2020: Technologies for Future Liquid Propellant Engines at ArianeGroup
Creators: name:  S. SOLLER 
Publisher: name: Proceedings of  the 9th European Conference for Aerospace Sciences. Lille, France, 27 June - 1 July, 2022
Year: 2022
Subjects: PROPULSION PHYSICS
LIQUID ROCKET ENGINE
SYSTEMS
NEW DEVELOPMENTS

description: While preparing the first launch of the new Ariane 6, ArianeGroup is performing several long-term research and technology projects to continuously prepare the implementation of innovative technologies for future liquid rocket engines. In this context, ArianeGroup has been performing the RT programme TARES 2020, which is dedicated to increase the technology readiness level of promising technologies to a level of TRL = 3-5 for later application on launcher engines. This activity has been supported by the German Space Agency DLR by a federal grant. Different fields of liquid propulsion subsystems have been addressed, covering cryogenic valves, ignition systems, gas generators and thrust chamber technologies. The publication highlights key results of this activity. In a cooperation with the institute for applied mechanics of the Rheinisch-Westfalische Technische Hochschule (RWTH) basic research and numerical model development have been performed to be able to predict material behaviour and mechanical properties of polymeric seal materials from room temperature down to cryogenic operating conditions. ArianeGroup performed a material characterisation program for various polymeric seal materials to characterise the elasto-plastic deformation behaviour from room temperature down to cryogenic temperatures. With the material data RWTH Aachen established a numerical model is being developed to describe the contact force and deformation of the seal during its operation cycle. The model can be used to optimise the design of the seal configuration for high robustness and tolerance against manufacturing deviation. Additionally, the model is a first step towards a predictive simulation of the leakage behaviour of the valve. In the field of additive manufacturing, a joint activity was performed together with the Chair of General Material Properties in order to investigate the effect of selective laser melting process parameters on the material properties and microstructure of Nickel-base super alloys and stainless steel 316L. Additionally, the effect of different heat treatment strategies on the evolution of the microstructure and the high-temperature properties of Nickel-base super alloys was studied, giving important insights into the correlation between process parameters, heat treatment and material properties. A significant amount of effort was spent on addressing key issues linked to the use of liquefied natural gas or methane as rocket fuel. For example, different ignition systems were benchmarked in a test campaign at representative transient start up conditions in a subscale test campaign. In a joint RT activity with CNES, a test campaign was performed to characterise the heat transfer characteristics of methane in sub- and transcritical operating conditions. Data were used to validate design tools in use at Arianegroup and scrutinised with respect to the effect of the so-called heat transfer deterioration, which is expected to occur if the coolant flow conditions inside the cooling channel approach the critical point of the fluid. In all of these fields, a regular exchange of results and alignment of future research activities has been performed with the research centres of DLR within the cooperation Propulsion 2025. Likewise the contribution to research networks like the French-German REST group or the German SFB Transregio 40 is to be mentioned. This fruitful exchange with universities and academia ensures the high level of research in combination with an orientation towards the application on future space engine systems. The full paper will present the results obtained in the different fields of research and technology in more detail.