Development of a Combustor Liner Composed of Ceramic Matrix Composite (CMC)

The Research Institute of Advanced Materials Gas-Generator (AMG), which is a joint effort by the Japan Key Technology Center and 14 firms in Japan, has, since fiscal year 1992, been conducting technological studies on an innovative gas generator that will use 20 percent less fuel, weigh 50 percent less, and emit 70 percent less NO_x than the conventional gas generator through the use of advanced materials. Within this project, there is an R&D program for applying ceramic matrix composite (CMC) liners to the combustor, which is a major component of the gas generator. In the course of R&D, continuous SiC fiber-reinforced SiC composite (SiC^F/SiC) was selected as the most suitable CMC for the combustor liner because of its thermal stability and formability. An evaluation of the applicability of the SiC^F/SiC composite to the combustor liner on the basis of an evaluation of its mechanical properties and stress analysis of a SiC^F/SiC combustor liner was carried out, and trial SiC^F/SiC combustor liners, the largest of which was 500-mm in diameter, were fabricated by the filament winding and PIP (polymer impregnation and pyrolysis) method. Using a SiC^F/SiC liner built to the actual dimensions, a noncooling combustion test was carried out and even when the gas temperature was raised to 1873K at outlet of the liner, no damage was observed after the test. Through our studies we have confirmed the applicability of the selected SiC^F/SiC composite as a combustor liner. In this paper, we describe the present state of the R&D of a CMC combustor liner.