Toward the Impact of Fuel Evaporation-Combustion Interaction on Spray Combustion in Gas Turbine Combustion Chambers. Part I: Effect of Partial Fuel Vaporization on Spray Combustion

Abstract

This work aims at investigating the impact of the interaction between evaporation process and combustion on spray combustion characteristics in gas turbine combustion chambers. It is subdivided into two parts. The first part studies how the evaporation process affects the behavior of partially pre-vaporized spray combustion. The second part attempts to answer the question how the fuel evaporation process behaves under premixed combustion conditions.For this purpose an Eulerian-Lagrangian RANS based procedure under a full two-way coupling was used. To describe the 3D-evaporation, two different (equilibrium and non-equilibrium) evaporation models based on the uniform temperature assumption were applied. For the combustion, the conditioned progress variable approach based on the Bray-Moss-Libby model has been adapted and used to account for both premixed and partially premixed combustion. To assess the numerical approach and to analyze the ongoing processes in the first part of this work, a model gas turbine combustor fired by kerosene fuel was considered. It features a partially premixed flame. Among others, the influence of both parameters, the mixing air temperature and the vaporization tube length, on the degree of vaporization and subsequently on spray flame characteristics has been pointed out. An overall agreement with available experimental data was achieved especially using the non-equilibrium evaporation model. With this confidence in place, further parameter studies could be consistently performed and additional information could be extracted to gain insights relevant to understanding the effects under study.