Session: 34-07 Centrifugal, combustor, and bearing methods

Paper Number: 121786

121786 - Combustor Design From a Turbine Perspective to Minimize the Effect of Turbulence 

During the gas turbine design process, control and optimization of turbulence characteristics at the combustor-turbine interface can lead to improved specific fuel consumption. Here, we use computational large-eddy simulations to explore the turbulent flow characteristics at the exit plane of two combustor designs: a baseline design corresponding to an idealized combustor simulator and a design that has been optimized to minimize turbulence intensity at the combustor exit while maintaining good mixing uniformity and low pressure drop. By comparing the two designs, we demonstrate that the size, orientation, and positioning of the primary zone and dilution jets are the primary drivers determining the structure of the turbulence exiting the combustor. We show that by exploiting physical parameters in the combustor we can shift the energy-containing eddies to larger scales, affecting both the turbulence decay rate and the interaction of the turbulence with the turbine boundary layers. In the optimized design, turbulence decays at a faster rate towards isotropic flow and we observe that Reynolds stresses are substantially decreased. Finally, we introduce a flat plate downstream of the combustor exit to quantify the boundary layer profile, skin friction, and boundary layer dissipation for each design. This work illustrates how understanding the mechanisms responsible for decreased turbulence at the combustor exit can aid designers in maximizing performance of the gas turbine, as well as demonstrating the potential of computational optimization for combustor design.

Presenting Author: Jennifer Miklaszewski University of Colorado Boulder

Presenting Author Biography: Jennifer Miklaszewski is a fourth-year PhD student at the University of Colorado Boulder Paul M. Rady Department of Mechanical Engineering. She received a bachelor's degree in mechanical engineering with a minor in global engineering studies and a master's degree in mechanical engineering from Purdue University. Her current field placement is with the Turbulence and Energy Systems Laboratory. She is interested in optimization methods for combustor design, turbulent modeling, and the interaction between gas turbine components.

Authors:

Jennifer Miklaszewski University of Colorado Boulder
Masha Folk Rolls-Royce North America
Peter Hamlington University of Colorado Boulder