Using the temperature profiles of the outer wall for all combustor types presented in the current study, the radiative heat transfer is estimated by the following expression:equation(12)Q?Rad=σ·2πro∑i=1nΔxi(Ti4-Ts4)Here ‘i’ is the number of intervals on which the outer wall temperature is evaluated.
The efficiency of a TPV array (ηTPV)(ηTPV) is a strong property of combustor’s material (emitter) and maximum power of the PV cell. To estimate this 3-Methyladenine efficiency, the current study assumes a thermally excited Co/Ni-doped MgO emitter for a GaSb TPV cell. For such an emitter and TPV type, the efficiency is reported to be 15.4% .
2.4. Turbulence models
2.5. Boundary conditions
•Inlet: Hydrogen–air mixture velocity, species concentration, temperature and turbulence intensity are all specified at the inlet. The numerical values for these parameters are taken from the experimental study by Li et al. .•Outlet: The pressure boundary condition is specified. Furthermore, the species and temperature gradients are taken to be 0.•Walls: Walls of the combustor at the inlet and exit planes are insulated.-kdTdxi=0.