Advanced nozzle concept trade-off and selection criteria based on launcher mission constraints
Creators: name:  F. WEBER 
name:   D. BIANCHI 
name:   F. NASUTI 
Publisher: name: Proceedings of  the 9th European Conference for Aerospace Sciences. Lille, France, 27 June - 1 July, 2022
Year: 2022
Subjects: PROPULSION PHYSICS
NOZZLE
TURBOPUMPS

description: In previous studies it has been shown that the operational effciency is one of the main demands of space transportation systems. In this context, performance losses caused by non-adaptation of the flow in the expansion process represent the largest loss source for conventional rocket nozzles, with losses up to 15%. The reason is that these nozzles can be adapted or optimally designed only for a single trajectory point along the entire ascent phase. In contrast, Advanced Nozzle Concepts (ANCs) such as, among others, expansion-deflection and plug/ aerospike nozzles are able to adapt to different altitudes. The latter concept adapts even theoretically up to its geometric expansion ratio. By increasing the engine performance through a reduction of the adaptation losses, the payload, for example, can be increased.2 Driven by this goal, ANCs have been explored for many years. However, the best ANC is very closely related to the architecture and mission constraints of the overall launcher system. These are, for example, the application such as main stage/ -upper stage operation, the launcher class covering for instance the number of stages, and the thrust range or the propellant combination that has to be used. The final paper is expected to provide an application-driven critical assessment and a detailed trade- off analysis and discussion of various ANCs and to analyze different selection criteria based on launcher architecture and mission constraints. These investigations will be largely based on the evaluation of literature studies that have already been carried out (both numerically and experimentally) and represent a first step towards more detailed analyses. For every space propulsion engineer this investigation will be helpful and necessary to select possible ANCs tailored on the specific system requirements. This preliminary assessment can then be followed by further analyses including for example CFD assessments of critical aspects of ANCs such as flow separation and heat fluxes in critical regions. After a verification and validation of the numerical simulations the design process can be finally completed by defining a system level integration methodology of the ANCs that will also include a novel upper-stage application. This work is framed within the ASCenSIon (Advancing Space Access Capabilities - Reusability and Multiple Satellite Injection) H2020 ITN consortium. The purpose of ASCenSIon project is to develop a program that focuses on several specific cutting-edge space research, particularly on launcher systems that are (partially) reusable and capable of injecting multiple payloads into multiple orbits.1 More than providing design concepts, the network aims to identify and advance critical technologies, such as for example the nozzle design, to prove a feasibility of these concepts. ASCenSIon is funded from the EUs Horizon 2020 research and innovation programme under Marie Sk?odowska-Curie grant agreement.