Session: 04-18: Combustor design IV

Paper Number: 104092

104092 - Numerical Modeling of Multiple Reacting Liquid Jets in Non-Uniform Crossflow for Gas Turbine Combustion Applications 

One of the most used spray configurations for gas turbines and power combustors is liquid jet in crossflow. The process of breakup of liquid jet is very complex and understanding this mechanism is of paramount importance in engine design. This has led to the commencement of several studies from leading research groups. Several new modeling methods such as the Madabhushi breakup model or more detailed VOF and Level set methods have been used successfully to understand and describe these complex breakup processes. However, most of these studies have been restricted to liquid jet in uniform single stream crossflow. In reality, these jets could be subjected to several gaseous streams and the breakup mechanism may vary significantly.  Recently there have been some studies to understand the effect of non-uniformities on the crossflow velocity distribution and the droplet diameter [1-2]. In such studies, the Madabhushi breakup model has been used to model non-reacting jets subjected to non-uniform crossflow. Non-uniform crossflow is created by co-directional and parallel gas flow using several hollow tubes. The current paper extends this application to reacting liquid jets similar to Gas Turbine applications operating at liquid baseload conditions. A modified version of the Madabhushi model as proposed by Lambert et. al is used here to simulate the jet breakup in a non-reacting multiphase flow simulation to get the spray regime. Subsequently, reacting simulation with FGM model was turned on to calculate the flame shape and combustion products. Model tuning has been conducted using University of Cincinnati Research data specifically designed for this configuration in partnership with General Electric Company. For turbulence, realizable k-ε with scalable wall function is used. The droplets are tracked using Ansys Fluent Discrete Particle Model (DPM). A second modeling approach VOF-to-DPM is also used which uses VOF equation along with LES with Dynamic Kinetic Energy Subgrid-Scale Model. This model requires no fine tuning of parameters and is more accurate but comes with more computational expense.

Various steady RANS and unsteady LES simulations are performed with pure diesel and heated non-uniform cross flows of 665F inside a chamber at a pressure of 45psi with Momentum ratio of 12. Due to challenges in experiments, the momentum ratio was lowered (from original planned J of 15) to have a stable flame and prevent blow out. As a result, the flame is near the bottom wall. This does create a modeling challenges to account for the heat loss effects. Overall, in this effort, the flame shape and extent of the flame near the wall has been captured compared to experiments. The droplet characteristics such as axial velocity, Sauter mean diameter and volumetric flux are compared with experimental measurements (at equaivalent non-reacting condition) and shows reasonable agreement. Overall, the liquid penetration and flame shape and exhaust concentrations is within reasonable accuracy. 

[1] Feiz, H. et al., "Numerical Modeling of Liquid Jet in NON-UNIFORM crossflow using enhanced Madabhushi Model" Turbomachinery Technical Conference and Exposition GT2022-82766

[2] Feiz, H. et al., “Numerical Modeling of MULTIPLE Liquid Jets in Crossflow for Gas Turbine Spray Characterization”, SCI-Tech Forum, January 2023

Presenting Author: Homayoon Feiz GE Power

Presenting Author Biography: Homayoon Feiz is a Technical Leader at GE Power, gas turbine technology laboratory (GTTL) located in Greenville, South Carolina. Feiz works for combustion engineering organization and he is leading physics-based modeling activities related to high hydrogen and liquid combustor design. He has a PhD in Aerospace engineering from Georgia Institute of Technology with a focus on large eddy simulations. He holds a mechanical professional engineering (PE) license from the state of South Carolina.

Prior to joining GE, Feiz was a technical leader at Northrop Grumman company and contributed to the design of NASA’s next generation crew exploration vehicle by conducting wind tunnel testing and performing CFD simulations using high performance computing systems.

Authors:

Homayoon Feiz GE Power
Hasan Karim GE Power
Wei Zhao GE Power
Jinkwan Song GE Power
Dominik Kubicki Institute of Aviation
Marcin Frackowiak Institute of Aviation
Vivek Kumar ANSYS Inc
Harshrajsinh Jadeja ANSYS Inc
Pravin Nakod ANSYS Inc
Sravan Kumar Nallamothu ANSYS Inc
Sourabh Shrivastava ANSYS Inc
Markus Lambert ANSYS Inc
Jong Guen Lee University of Cincinnati Research Institute