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This thesis focuses on the use of Large Eddy Simulations (LES) to investigate non-reacting and reacting multiphase flows. In the first part, the study explores the impact of increasing Weber number on spray and flow characteristics in a jet in crossflow configuration. The results demonstrate that as the Weber number increases, finer droplets are formed, leading to increased droplet velocities and adjustments to the freestream more quickly. The analysis also reveals a linear decline in droplet size with increasing Weber number, shedding light on the influence of this parameter on spray characteristics.Moving on to the combustion simulation, the thesis examines the combustion of a liquid fuel jet injected into crossflowing air, utilizing a v-gutter bluff-body for flame stabilization. Surprisingly, the study finds that a majority of droplets impinging upon the surface of the v-gutter get deposited, forming a thin film that eventually breaks up downstream. This unexpected behavior results in the formation of a nearly stoichiometric fuel-air mixture, indicating the high efficiency of the current configuration for achieving clean combustion. Detailed analysis of mean profiles reveals asymmetric temperature distribution, with higher temperatures closer to the bottom wall of the test section due to concentrated dispersed droplets trapped in the wake of the v-gutter. However, the velocity profiles become nearly symmetric at the exit of the combustor, indicating sufficient residence time for velocity gradients to readjust.In the last part of the thesis, the focus shifts to the simulation of non-reacting flow in a full-scale FAA Nexgen burner. The study provides insights into the unsteady flowfield, identification of flow structures, and quantification of swirl generation and turbulence caused by the flow's unsteadiness within the turbulator. It reveals the transition from laminar to turbulent flow, with maximum turbulence production occurring within the pockets of the turbulator blades. Recirculation zones are identified within the combustor cone, and the detailed flowfield obtained from the simulations offers valuable information for understanding the influence of swirl, fluid turbulence, and flow structures on the combustion process and optimizing burner design.Overall, this thesis contributes significant insights into the characteristics of multiphase flows, combustion dynamics, and flow structures within different configurations. The findings provide a benchmark for future research and can aid in the design and optimization of similar systems.