Numerical Study of Lean-Direct Injection Combustor With Discrete-Jet Swirlers Using Reynolds Stress Model

2003 ◽  
Vol 125 (4) ◽  
pp. 1059-1065 ◽  
Author(s):  
S. L. Yang ◽  
Y. K. Siow ◽  
C. Y. Teo ◽  
R. R. Tacina ◽  
A. C. Iannetti ◽  
...  
Keyword(s):  
Reynolds Stress ◽  
Turbulence Model ◽  
Numerical Study ◽  
Direct Injection ◽  
Reynolds Stress Model ◽  
Lean Direct Injection ◽  
Velocity Gradients ◽  
Recirculation Zones ◽  
Computational Fluid Dynamics Cfd ◽  
Reynolds Averaging

The flowfield in a lean-direct injection (LDI) combustor with discrete-jet swirlers is described and analyzed using a computational fluid dynamics (CFD) code with a Reynolds stress turbulence model (RSTM). The results from the RSTM are compared to time-averaged laser-Doppler velocimetry (LDV) data, as well as results from the National Combustion Code (NCC) that has a cubic nonlinear κ-ε turbulence model, and from the KIVA code using the standard κ-ε model. The comparisons of results indicate that the RSTM accurately describes the flow details and resolves recirculation zones and high velocity gradients while the κ-ε models are unable to capture most flow structures. This confirms that, within the Reynolds averaging approach, the higher-order RSTM is preferred for simulating complex flowfields where separations, strong anisotropy, and high swirl are present.

Numerical Study of Nonreacting Gas Turbine Combustor Swirl Flow Using Reynolds Stress Model

2003 ◽  
Vol 125 (3) ◽  
pp. 804-811 ◽  
Author(s):  
S. L. Yang ◽  
Y. K. Siow ◽  
B. D. Peschke ◽  
R. R. Tacina
Keyword(s):  
Experimental Data ◽  
Gas Turbine ◽  
Reynolds Stress ◽  
Turbulence Model ◽  
Numerical Study ◽  
Three Dimensional ◽  
Flow Simulation ◽  
Reynolds Stress Model ◽  
Swirl Flow ◽  
High Degree

This paper presents recent research on the use of a Reynolds stress turbulence model (RSTM) for three-dimensional flowfield simulation inside gas turbine combustors. It intends to show the motivations for using the RSTM in engine flow simulation, to present a further validation of the RSTM implementation in the KIVA code using the available experimental data, and to provide comparisons between RSTM and k-ε turbulence model results for chemically nonreacting swirling flows. The results show that, for high-degree swirl flow, the RSTM can provide predictions in favorable agreement with the experimental data, and that the RSTM predicts recirculations and high velocity gradients better than does the k-ε turbulence model. The results also indicate that the choice of swirler has a significant influence on the structure of the combustor flowfield.

Multi-objective Numerical Investigation of a Generic Airblast Injector Design

2016 ◽  
Vol 138 (9) ◽  
Author(s):  
Adam L. Comer ◽  
Timoleon Kipouros ◽  
R. Stewart Cant
Keyword(s):  
Design Space ◽  
Direct Injection ◽  
Design Studies ◽  
Lean Direct Injection ◽  
Analytical Work ◽  
Computational Fluid Dynamics Cfd ◽  
Aero Engines ◽  
Semi Empirical ◽  
Injector Design ◽  
Low Order

In combustor design for aero-engines, engineers face multiple opposing objectives with strict constraints. The trend toward lean direct injection (LDI) combustors suggests a growing emphasis on injector design to balance these objectives. Decades of empirical and analytical work have produced low-order methods, including semi-empirical and semi-analytical correlations and models of combustors and their components, but detailed modeling of injector and combustor behavior requires computational fluid dynamics (CFD). In this study, an application of low-order methods and published guidelines yielded generic injector and combustor geometries, as well as CFD boundary conditions of parameterized injector designs. Moreover, semi-empirical correlations combined with a numerical spray combustion solver provided injector design evaluations in terms of pattern factor, thermoacoustic performance, and certain emissions. Automation and parallel coordinate visualization enabled exploration of the dual-swirler airblast injector design space, which is often neglected in published combustor design studies.

Large-Eddy Simulation of a Swirl-Stabilized, Lean Direct Injection Spray Combustor

2006 ◽  
Author(s):  
Mehmet Kırtas¸ ◽  
Nayan Patel ◽  
Vaidyanathan Sankaran ◽  
Suresh Menon
Keyword(s):  
Large Eddy Simulation ◽  
Vortex Breakdown ◽  
Direct Injection ◽  
Reacting Flow ◽  
Mean Velocity ◽  
Recirculation Bubble ◽  
Lean Direct Injection ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Recirculation Zones

Large-eddy simulation (LES) of a lean-direct injection (LDI) combustor is reported in this paper. The full combustor and all the six swirl vanes are resolved and both cold and reacting flow simulations are performed. Cold flow predictions with LES indicate the presence of a broad central recirculation zone due to vortex breakdown phenomenon near the dump plane and two corner recirculation zones at the top and bottom corner of the combustor. These predicted features compare well with the experimental non-reacting data. Reacting case simulated a liquid Jet-A fuel spray using a Lagrangian approach. A three-step kinetics model that included CO and NO is used for the chemistry. Comparison of mean velocity field predicted in the reacting LES with experiments shows reasonable agreement. Comparison with the non-reacting case shows that the centerline recirculation bubble is shorter but more intense in the reacting case.

Numerical study of turbulent round jet in a uniform counterflow using a second order Reynolds Stress Model

2015 ◽  
Vol 9 (4) ◽  
pp. 482-495 ◽  
Author(s):  
Amani Amamou ◽  
Sabra Habli ◽  
Nejla Mahjoub Saïd ◽  
Philippe Bournot ◽  
Georges Le Palec
Keyword(s):  
Reynolds Stress ◽  
Numerical Study ◽  
Reynolds Stress Model ◽  
Second Order ◽  
Stress Model ◽  
Round Jet

A Numerical Study of Vortex Breakdown in Turbulent Swirling Flows

1999 ◽  
Vol 122 (1) ◽  
pp. 179-183 ◽  
Author(s):  
Robert E. Spall ◽  
Blake M. Ashby
Keyword(s):  
Reynolds Stress ◽  
Stokes Equations ◽  
Vortex Breakdown ◽  
Numerical Study ◽  
Reynolds Stress Model ◽  
Navier Stokes ◽  
Stress Model ◽  
Mean Flow ◽  
Navier Stokes Equations ◽  
The Mean

Solutions to the incompressible Reynolds-averaged Navier–Stokes equations have been obtained for turbulent vortex breakdown within a slightly diverging tube. Inlet boundary conditions were derived from available experimental data for the mean flow and turbulence kinetic energy. The performance of both two-equation and full differential Reynolds stress models was evaluated. Axisymmetric results revealed that the initiation of vortex breakdown was reasonably well predicted by the differential Reynolds stress model. However, the standard K-ε model failed to predict the occurrence of breakdown. The differential Reynolds stress model also predicted satisfactorily the mean azimuthal and axial velocity profiles downstream of the breakdown, whereas results using the K-ε model were unsatisfactory. [S0098-2202(00)01601-1]

Swirl and Combustion Effects on Flow Dynamics in Lean Direct Injection Gas Turbine Combustion

2003 ◽  
Author(s):  
S. Archer ◽  
A. K. Gupta
Keyword(s):  
Gas Turbine ◽  
Direct Injection ◽  
Model Development ◽  
Flow Characteristics ◽  
Flow Dynamics ◽  
Outer Flow ◽  
Lean Direct Injection ◽  
Image Velocimetry ◽  
Recirculation Zones ◽  
Gas Turbine Combustion

The effect of swirl and combustion are presented for a Lean Direct Injection (LDI) configuration in gas turbine combustion. Specifically, the effect of radial distribution of combustion air and swirl in a burner are examined under nonburning and burning conditions using propane as the fuel. The present study explores single swirler interaction with the use of an experimental double concentric swirl burner that simulates one swirler of a practical gas turbine combustor. Flowfield data has been obtained using Particle Image Velocimetry (PIV) for varying swirl distributions. The flow characteristics of the resulting flowfields have been examined under lean direct injection (LDI) conditions. The affects of coand counter-swirl have also been carried out. Results showed that both swirl and combustion has significant effect on the characteristics of the internal and external recirculation zones. Combustion provides greater axial velocities than their counter non-combustion conditions. The counter-swirl combination resulted in smaller and more well defined internal recirculation regions. The results provide the role of swirl and combustion on the mean and turbulence characteristics of flows over a range of swirl and shear conditions between the inner and outer flow of the burner. This data provides important insights on the flow dynamics in addition to providing data for model validation and model development.

Development and Application of a Two-Scale Non-Linear Reynolds Stress Turbulence Model

2007 ◽  
Author(s):  
S. Y. Jaw ◽  
R. R. Hwang
Keyword(s):  
Turbulent Flows ◽  
Reynolds Stress ◽  
Turbulence Model ◽  
Dissipation Rate ◽  
Reynolds Stress Model ◽  
Stress Model ◽  
Turbulence Scale ◽  
Non Linear ◽  
Algebraic Reynolds Stress Model ◽  
Near Wall

To improve the prediction of turbulent flows, a two-scale, non-linear Reynolds stress turbulence model is proposed in this study. It is known that for the near-wall low-Reynolds number turbulent flows, the Kolmogorov turbulence scale, based on the fluid kinematic viscosity and dissipation rate of turbulent kinetic energy (ν,ε), is the dominant turbulence scale, hence it is adopted to address the viscous effects and the rapid increase of dissipation rate in the near wall region. As a wall is approached, the turbulence scale transits smoothly from turbulent kinetic energy based (k, ε) scale to (ν,ε) scale. The damping functions of the low-Reynolds number models can thus be simplified and the near-wall turbulence characteristics, such as the ε distribution, are correctly reproduced. Furthermore, to improve the prediction of the anisotropic Reynolds stresses for complex flows, a nonlinear algebraic Reynolds stress model is incorporated. The same turbulence scales are adopted in the nonlinear algebraic Reynolds stress model. The developed two-scale non-linear Reynolds stress model is first calibrated with the DNS budgets of two-dimensional channel flows, and then applied to predict the separation flow behind a backward facing step. It is found that the proposed two-scale nonlinear Reynolds stress turbulence model is capable of providing satisfactory results without increasing much computation efforts or causing numerical stability problems.

Numerical Study on the Characteristics of Lean Direct Injection Combustor With Elevated Fuel Temperatures

2021 ◽  
Author(s):  
Jinghe Lu ◽  
Xiao Liu ◽  
Shuying Li ◽  
Enhui Liu ◽  
Zhihao Zhang ◽  
...  
Keyword(s):  
Numerical Study ◽  
Direct Injection ◽  
Lean Direct Injection
Sign in / Sign up

Export Citation Format

Share Document