Large eddy simulations of reacting and non-reacting transcritical fuel sprays using multiphase thermodynamics
arXiv:2205.07504 · doi:10.1063/5.0099154
Abstract
Accurate simulations of high-pressure transcritical fuel sprays are essential for the design and optimization of next-generation gas turbines, internal combustion engines, and liquid propellant rocket engines. Most important and challenging is the accurate modelling of complex real-gas effects in high-pressure environments, especially the hybrid subcritical-to-supercritical mode of evaporation during the mixing of fuel and oxidizer. In this paper, we present a novel modeling framework for high-fidelity simulations of reacting and non-reacting transcritical fuel sprays. In this method, the high-pressure jet disintegration is modeled using a diffuse interface method with multiphase thermodynamics, which combines multi-component real-fluid kinetic and caloric state equations with vapor-liquid equilibrium calculations in order to compute thermodynamic properties of the mixture at transcritical pressures. All multiphase thermodynamic formulations are presented for general cubic state equations coupled with a rapid phase-equilibrium calculation method. The proposed method represents multiphase turbulent fluid flows at transcritical pressures without relying on any semi-empirical break-up and evaporation models. Combustion source terms are evaluated using a finite-rate chemistry model, including real-gas effects based on the fugacity of the species in the mixture. The adaptive local deconvolution method (ALDM) is used as a physically consistent turbulence model for large-eddy simulation (LES). LES results show a very good agreement with available experimental data for the reacting and non-reacting ECN Spray A at transcritical operating conditions.
This paper is part of the Physics of Fluids themed issue Development and Validation of Models for Turbulent Reacting Flows in honor of Professor Michael Pfitzner on the occasion of his retirement