Open AccessDetailed Analysis of the Thermal Wall Heat Load in Annular Combustors
Author(s) -
Werner Krebs,
Günther Walz,
Stefan Hoffmann,
Hans Judith
Publication year - 1999
Publication title -
volume 2: coal, biomass and alternative fuels; combustion and fuels; oil and gas applications; cycle innovations
Language(s) - English
Resource type - Conference proceedings
DOI - 10.1115/99-gt-134
Subject(s) - combustor , materials science , heat flux , combustion chamber , thermal conductivity , combustion , mechanics , thermal radiation , convection , convective heat transfer , nuclear engineering , thermal , power density , heat transfer , thermodynamics , composite material , power (physics) , chemistry , physics , engineering , organic chemistry
A detailed thermal analysis involving both measurements and calculations has been carried out in order to determine the wall heal load and to optimize the amount of cooling air for an annular combustor. In calculations, the convective wall heat flux has been detemined by application of a 3D Navier-Stokes Code. Furthermore, the radiation exchange between the hot combustion gases and the liner has been calculated using a multidimensional spectral approach. Although a quite high thermal power density is found within the combustion chamber the wall heat load is at a low level. Values are well below 80 kW/m2, due to the application of ceramic tiles which have a low thermal conductivity. The wall heat load is dominated by radiation emitted in the lower gas radiation bands (λ < 2.9 μm). The convective wall heat flux is nearly balanced out by the sealing air which is discharged through gaps between the ceramic tiles. The cooling effect of the sealing air, however, is strongly influenced by the 3D near wall flow field in the combustion chamber.