Study on CerAMfacturing of Novel Alumina Aerospike Nozzles by Lithography-Based Ceramic Vat Photopolymerization (CerAM VPP)

Abstract

Advanced ceramics are recognized as key enabling materials possessing combinations of properties not achievable in other material classes. They provide very high thermal, chemical and mechanical resistance and typically exhibit lower densities than metals. These properties predestine ceramics for many different applications, especially those in space. Aerospike nozzles promise an increased performance compared to classic bell nozzles but are also inherently more complex to manufacture due to their shape. Additive manufacturing (AM) drastically simplifies or even enables the fabrication of very complex structures while minimizing the number of individual parts. The applicability of ceramic AM (“CerAMfacturing”) on rocket engines and especially nozzles is consequently investigated in the frame of the “MACARONIS” project, a cooperation of the Institute of Aerospace Engineering at Technische Universität Dresden and the Fraunhofer Institute for Ceramic Technologies and Systems (IKTS) in Dresden. The goal is to develop novel filigree aerospike nozzles with 2.5 N and 10 N thrust. For this purpose, CerAM VPP (ceramic AM via Vat Photopolymerization) using photoreactive and highly particle-filled suspensions was utilized. This contribution gives an overview of the component development starting from CAD modeling, suspension development based on alumina AES-11C, heat treatment and investigation of the microstructure of the sintered components. It could be shown that modifying the suspension composition significantly reduced the formation of cracks during processing, resulting in defect-free filigree aerospike nozzles for application in space.

Vat Photopolymerization of Synthetic Isoprene Rubber Latexes

“…The EnvisionOne 3D printer from EnvisionTec is equipped with an oxygen-permeable substrate, creating a dead zone layer that inhibited typical radical polymerization and prevented printed objects from adhering to the vat. This feature minimized adhesion and pealing force between each photocured layer and the bottom substrate, providing a particular advantage for printing soft materials, e.g., SIR latex ( G n 0 of photocured SIR was lower than 20k Pa); otherwise, the detachment process of each photocured layer from the bottom substrate will risk the fidelity of the printed green body . SIR_16.7S, SIR containing 16.7 wt % scaffold, was experimentally determined to exemplify printing, utilizing 2.5 s of irradiation for each layer with a 100 μm thickness after optimization.…”

Theoretical Analysis and Verification on Plastic Deformation Behavior of Rocket Nozzle Using a Novel Tube Upsetting-Bulging Method

“…It converts the chemical energy generated by a propellant into kinetic energy, which can provide the driving force for the rocket. Therefore, the rocket nozzle is extremely important to the safe flight of the rocket [ 2 , 3 , 4 ]. The rocket nozzle is subjected to 6–10 Mpa pressure and high temperature (2800–3400 K) gas erosion when working [ 5 , 6 , 7 ].…”

Validation of a numerical strategy to simulate the expansion around a plug nozzle

“…The Beijing University of Aeronautics and Astronautics has developed an optimization method to design aerospike contours that maximize total impulse from sea level to the design altitude [1]. Technische Universität Dresden has studied thrust vectoring control systems and ceramic additive manufacturing techniques [2,3]. Accurate thrust prediction in aerospike engines requires considering the interaction between the plume and external flow, posing a significant simulation challenge.…”