Combustor and Material Integration for high speed aircraft in the European research Program ATLLAS2

Abstract

Hypersonic airliner would be exposed to temperatures that are beyond the limits of classical aircraft materials. In order to handle this problem the latest developments of new materials and composite structures suitable for high temperature application need to be taken into account. The focus of the European Research program ATLLAS is on advanced lightweight , high-temperature material development strongly linked to a high-speed passenger aircraft design. ATLLAS stands for Aerodynamic and Thermal Load Interactions with Lightweight Advanced Materials for High Speed Flight. The 4 years program ATLLAS-II is a logical continuation project built upon the experience and technology development gained within ATLLAS-I. The corresponding work related to combustor structures and material integration deals with the opportunity to investigate at academic level, both in basic and relevant environment, different solutions possibly usable to ensure the long range cruise of a high speed airliner. Different materials (UTHC, CMC, metallic) and different cooling techniques (radiation, convective, transpiration) are studied. Available numerical or semi-empirical tools are used to prepare the test, to design the different architectures. A pin fin experiment allows to better know the pressure drop and the heat transfer for different channel patterns with thermal cristal techniques. The ERBURIG K long 2 duration test facility allow to characterize different ceramic matrix composite uncooled samples and will allow to realize, at small scale, a long duration (several hours) investigation of cooled ceramic structure in PTAH-SOCAR technology. A multifonctionnal metallic transpiration cooled HSS panel using Hollow Spheres Stacking as core material was designed and preliminary tested in cold conditions with GN2 and in hot conditions with infra red lamps under 1 MW/m² heat flux. CMC and UHTC materials are used to design, manufacture and test generic fin injectors usable in high speed combustors. Industrial hypersonic METHYLE test facility is used to test in relevant Mach 6 combustor environment HSS panel as well as advanced fin injectors. Hot and cold permeability of composites is documented with GN2 and GH2. Numerical models are used in accordance with the experiments, some examples are given in the present paper. Nomenclature C/C-SiC = carbon fibre reinforced silicon carbide CFD = computational fluid dynamics CMC = ceramic matrix composite ERBURIG K = Environmental Relevant Burner Rig-Kerosene HSS = Hollow Spheres Stacking (sandwich) GN 2 = gaseous nitrogen METHYLE= French acronym for long duration hypersonic technology test facility O 2 = oxygen SiC/SiCN = silicon carbide fibre reinforced silicon carbonitride TLC = Thermochromic Liquid Crystals UHTC = ultra high temperature ceramic USTUTT/ITLR = University of Stuttgart WHIPOX = wound highly porous oxide

Ultra-high temperature ceramics developments for hypersonic applications

“…UHTCs are compounds made of borides, carbides and nitrides such as ZrB 2 , HfB 2 , ZrC, HfC, TaC, HfN which are characterised by high melting points (Table 1), high hardness, chemical inertness and relatively good resistance to oxidation in severe environments. For a few years, the Materials and Structures Department of ONERA is involved in different projects concerning UHTC material developments from manufacturing to thermomechanical assessments of components in realistic environment and oxidation resistance understanding [6][7][8][9][10][11][12]. Most of our work on monolithic ceramics has been carried out on diborides of the group IVb (ZrB 2 and HfB 2 ) which possess very high melting points (>3200°C), excellent thermomechanical properties and a good resistance to oxidation when ~20%vol.…”

Development of Ultra-High Temperature Ceramics: From Monoliths to Composites

“…Moreover, oxidation resistance is ensured thanks to the formation of a multi-oxide scale composed of a MeO 2 skeleton and a glassy borosilicate layer at high temperatures [1][2][3][4][5]. Since a decade, Onera has carried out several activities on UHTC materials from manufacturing to thermomechanical assessments of components in realistic environment and oxidation resistance understanding [6][7][8][9]. This paper is an outline of the work which has been done on these materials in the Materials and Structures Department.…”