Session: 04-21 Combustion Emissions I

Submission Number: 177144

Numerical Analysis of Flow Microstructure Around Cooling Jets in an Annular Combustor: Effects of Kerosene Droplet Size on Mixing, Emissions, Temperature Variance and Pattern Factor 

Gas dynamics and flow microstructure around primary and dilution liner cooling jets in an annular combustion chamber are investigated to quantify how kerosene droplet size governs mixing, NOx and CO formation, and temperature variance. A periodic 20-degree annular combustor sector is simulated using CFD RANS modeling with a combination of finite-rate chemistry and the eddy-dissipation model for combustion of gaseous kerosene, participating radiation P1 model, and thermal and prompt NOx formation. Four cases with hollow cone sprays with Sauter Mean Diameters (SMD) from 15 to 45 µm are assessed with the Rosin–Rammler droplet distribution. Diagnostics include temperature, temperature variance, NOx and CO formation, liquid fuel vapor, droplet-cluster tracks, and liner temperature on planes bracketing the primary and dilution jets and at the combustor outlet.

Smaller droplets (15–25 µm) evaporate within or just downstream of the primary zone, producing a compact hot core, thin jet-film layers, higher thermal NOx, and low CO localized to primary-jet shear. Larger droplets (35–45 µm) preferentially migrate toward the liners and reach the dilution row, forming near-wall vapor clusters co-located with elevated temperature variance and CO in jet/film shear layers, while suppressing NOx through cooling and reduced high-temperature residence. At the outlet, an intermediate droplet size yields the most uniform temperature field, whereas the largest droplets produce the strongest hot–cold contrast. Findings clarify the coupling between spray preparation and jet-in-crossflow gas dynamics and provide guidance on selecting droplet size and dilution-jet momentum to balance NOx and CO and exit temperature uniformity.

Presenting Author: Masoud Hajivand National Aerospace University "Kharkiv Aviation Institute",Ukraine

Presenting Author Biography: Masoud Hajivand is a Ph.D. candidate at the Department of Aeroengine Design, National Aerospace University “Kharkiv Aviation Institute” (KhAI), Ukraine. His research focuses on combustion processes in gas turbine engines, with particular emphasis on CFD simulation of combustion processes in gas turbine low-emission combustion chambers, emission reduction, and flame stabilization techniques, including deep research on the flow behavior around the cooling jets and their design. He has conducted several investigations on the influence of new generation swirler geometry, mixing, and fuel spray parameters on temperature distribution and emission formation. Masoud has more than ten years of experience teaching thermodynamics and combustion theory and is currently residing in Germany, continuing his research on low-emission combustion systems and advanced numerical modeling for aeroengine applications with several publications in this area.

Authors:

Masoud Hajivand National Aerospace University "Kharkiv Aviation Institute",Ukraine
Majid Asli Brandenburg University of Technology Cottbus-Senftenberg, Cottbus, Germany
Dmytro Dolmatov National Aerospace University "Kharkiv Aviation Institute",Ukraine
Sergiy Yepifanov National Aerospace University "Kharkiv Aviation Institute",Ukraine