Skeletal Mechanism of the Methane Oxidation for Space Propulsion Applications

Abstract

A skeletal chemical kinetic model for СН 4 /air combustion with 100 reactions and 24 chemical species was developed from the detailed mechanism, with 42 species and 298 reactions. The mechanism reduction was performed with the multi target reduction strategy realized in the in-house developed DLR RedMaster code. RedMaster is able to analyze the different chemical processes (ignition delay time and laminar flame speed) in the given time and height points. The obtained reduced model describes satisfactory experimental data for ignition delay and flame speed under conditions: p 5 = 1-50 bar, T 5 = 940K-210K, f = 0.5−2; p = 1-60 bar, T 0 = 300K, f = 0.6−1.4. Some problems related to reaction mechanism reduction are analyzed.

Numerical Investigation of Flow and Combustion in a Single Element GCH4/Gox Rocket Combustor

“…The impact of this assumption will be investigated further in the future. As chemical kinetic mechanism the scheme presented by Slavinskaya et al 8 was used. Turbulent Prandtl and Schmidt numbers were set to a constant value of 0.9 and 0.6 respectively.…”

“…Turbulence is modeled using a q-ω model, which allows the resolution of the wall up to y+ values below one. The combustion process is modeled using a laminar finite rate chemistry approach with the chemical kinetic scheme by Slavinskaya et al 8 Turbulent Prandtl and Schmidt numbers were set to 0.9 and 0.7 all throughout the domain. A study of the impact of these two parameters for TASCOM3D was presented in Keller.…”

“…The local flame structure is represented by a flamelet library that has been generated using the reduced methane mechanism of Slavinskaya containing 21 species and 97 reactions. 8 A power law is used for the molecular viscosity and the thermal conductivity is computed using the viscosity, specific heat capacity at constant pressure and a constant molecular Prandtl number. The coefficients have been fitted to the Chapman-Enskog theory.…”

“…As turbulence model a two-layer k-ε model was used resolving the wall to y+ values smaller than one. As combustion model a laminar finite rate chemistry employing the kinetic chemistry scheme described in Slavinskaya et al 8 was used. The turbulent Prandtl and Schmidt numbers were set to a constant values of 0.9 and 0.9.…”

“…A reduced chemical scheme by Lu 20 is used to capture combustion kinetics. CERFACS is the only group using a kinetic scheme other than the scheme by Slavinskaya et al 8 Rather than modeling turbulence chemistry interaction it is fully resolved on the mesh. Turbulent Prandtl and Schmidt numbers were set to 0.7 and 0.7 all throughout the domain on a subgrid level.…”