Navier-Stokes calculations of multi-dimensional flows with complex chemical kinetics

Abstract

Multi-dimensional flows have been calculated with complex chemical kinetics for hydrocarbon fuels. The flows include both premixed and diffusion flames, and there is a wide variation of both thermodynamic and chemical reaction conditions. The numerical methods have included an implicit block solver of the ADI type for the transport equations, and the low Mach number limit has been taken for the calculation of the pressure field. The applications consisted of a steady premixed methane flame about a hot sphere, and the time-dependent ignition of a methanol droplet in air. The methane calculation has been compared to a detailed stagnation point calculation, and the results compare favorably. The methanol droplet flow includes the gas, liquid, and interface conditions, and the calculation has been performed under diesel engine thermodynamic conditions. The methane flame was calculated with only temperature change error control and this form of error control was tested first on zero and one-dimensional models with the same chemistry. With this type of error control the time dependent calculation was stable, and steady state was approached rapidly. These calculations of complex chemical kinetics required substantial computer time, but the computational times are not large when compared to the potential of massively parallel computers. The methods used in the paper can be extended to parallel machines in a straight forward manner.