The Effect of Dilution Air Jets on Aero-Engine Combustor Performance

Xiao, Yinli; Cao, Zhibo; Wang, Changwu

doi:10.1515/tjj-2018-0045

Cited by 6 publications

(3 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This study shows that a nonuniform velocity profile due to a high-momentum dilution jet can have a more significant effect on the turbine than previously thought. Xiao 18 analyzed the effect of adjusting the dilution holes on the flow field and performance of the combustor by numerical simulation. The results show that the change in dilution air jet distribution has a large effect on the combustion efficiency and pattern profile.…”

Section: Introductionmentioning

confidence: 99%

Cooling characteristics of dilution holes in can-type combustor of micro gas turbine

Wang

Liu

Wang

et al. 2023

Proceedings of the Institution of Mechanical Engineers, Part A:

View full text Add to dashboard Cite

For the purpose of studying the effect of structural changes in the dilution zone on the main performance evaluation parameters of the combustor, a can-type combustor of a micro gas turbine containing 16 dilution holes was used as the original structure. Seven optimization cases were designed by adjusting the number of dilution holes and the area of single hole in the range of hole numbers from 8 to 28 while keeping the total area of dilution holes. The main conclusions obtained by the numerical simulation study are as follows. The total flow of the dilution zone decreases with the number of holes reduce but due to the increase of single hole flow with the area, the airflow rigidity is significantly enhanced, so the entire airflow is disturbed more strongly and the dilution effect is strengthened. In general, the total pressure loss of the combustor presented an increasing trend with the decrease in the number of holes, and the pressure loss reaches a minimum value of 3400 Pa when the number of holes is 14. The combustion efficiency decreased as the number of holes increased, when the hole numbers increased to 20, the combustion efficiency dropped abruptly below 95%. The variation tendency of outlet temperature distribution factor (OTDF) is generally consistent with the combustion efficiency, and the minimum OTDF is 0.29 for the number of holes of 28. In summary, compared with the original structure with 16 holes, the OTDF decreases by 7.69%, the NOx concentration decreases by 16.67%, and the combustion efficiency increases by 3.1% when the number of holes is 8. Although the total pressure loss is increased by 8%, it is still within a reasonable range. Therefore the combustor with 8 holes can be considered a better optimized case.

show abstract

Section: Introductionmentioning

confidence: 99%

Cooling characteristics of dilution holes in can-type combustor of micro gas turbine

Wang

Liu

Wang

et al. 2023

Proceedings of the Institution of Mechanical Engineers, Part A:

View full text Add to dashboard Cite

show abstract

“…Practical gas turbines featuring swirl stabilised flame burners further include dilution (side) jets to affect downstream reactant mixing with cooler dilution air thereby helping to control combustion temperature and limit pollutant emissions (particularly oxides of nitrogen). [6][7][8][9] Whilst earlier works have looked into either BB jets [10][11][12] or dilution jets in crossflow regimes, 8,[13][14][15][16] no attempt has been made to study the influence of side dilution jets on the flow field and turbulent mixing of non-swirling and swirling BB stabilised jets in geometries similar to those in industrial combustors. With the above in mind, the present study numerically investigates the impact of side dilution jets on the flow features, turbulence field, and mixing of BB jets, both non-swirling and swirling confined flows.…”

Section: Introductionmentioning

confidence: 99%

“…Whilst Prenter et al 16 conducted 3D, steady RANS simulations with different turbulence models on an annular combustor test rig, and found that all models under predicted lateral mixing and spreading with the exception of the k-ε RNG (Re-normalization group) and RSM (Reynolds Stress Model) that slightly over predicted jet penetration, the velocity field and flow features arising from introducing side dilution jets were not discussed. In terms of flow field, Xiao et al 9 applied RANS modelling to investigate the influence of dilution jets (primary and secondary) on the flow features of aero-engine combustor. It was established that shifting the axial location of secondary dilution jets upstream and downstream resulted in shrinkage and expansion of central recirculation zone respectively.…”

Section: Introductionmentioning

confidence: 99%

Effect of side dilution jets on the velocity field and mixing in swirl and bluff-body stabilised annular confined flows

Gillani

Al-Abdeli

Tian

2022

Proceedings of the Institution of Mechanical Engineers, Part A:

View full text Add to dashboard Cite

Stationary and mobile power generation systems, as well as those for aero propulsion, continue to rely heavily on gas turbines. Operational envelopes which critically depends on (flame) jet stabilisation mechanisms, such as swirl, are also affected by considerations for emissions control. In this context, the evolving swirling flow domains feature injection of side (peripheral) dilution air. Despite this, the role of side dilution jets on modifying the flow, turbulence, and mixing fields of turbulent bluff-body (BB) stabilised (swirling) annular flows has not been investigated. This study uses three-dimensional simulations, supported with experimental data to establish boundary conditions, to investigate the interaction of side dilution jets (Red = 18,000) with both non-swirling (S = 0) and swirling (S = 0.3) turbulent BB stabilised annular flows (Res = 35,500). Constant Temperature Anemometry (CTA) measurements are conducted to resolve inlet boundary conditions. The Reynolds Stress Model (RSM) and species transport model (isothermal) are used with validations against benchmark datasets. Results show that the introduction of side dilution jets into a confined domain, whether swirling or not, induces (asymmetrical) Peripheral Recirculation Zones (PRZ). However, the strength, length, and location of PRZ varies with swirl and the downstream positioning of side dilution jets (H = 2.6D, 6.6D). Additionally, side dilution jets increase centreline velocity decay for both, non-swirling and swirling BB flows. In terms of turbulence characteristics, addition of side dilution jets leads to significant gains in shear layer turbulence with an increase of 72% and 35% in turbulent kinetic energy for non-swirling and swirling BB flows, respectively. Analysis of the mixing characteristics shows negligible impact of side dilution jets in the upstream region, however, from x/D > 3 considerable improvement in central jet (fuel) mixing is observed.

show abstract

Influence of air distribution on combustion characteristics of a micro gas turbine fuelled by hydrogen-doped methane

Liu

et al. 2022

Energy Reports

View full text Add to dashboard Cite

The Effect of Dilution Air Jets on Aero-Engine Combustor Performance

Cited by 6 publications

References 1 publication

Cooling characteristics of dilution holes in can-type combustor of micro gas turbine

Cooling characteristics of dilution holes in can-type combustor of micro gas turbine

Effect of side dilution jets on the velocity field and mixing in swirl and bluff-body stabilised annular confined flows

Influence of air distribution on combustion characteristics of a micro gas turbine fuelled by hydrogen-doped methane

Contact Info

Product

Resources

About