Spreadsheet calculations of jets in crossflow: opposed rows of inline and staggered round holes

Holdeman, J. D.; Clisset, James R.; Moder, Jeffrey P.

doi:10.1007/s00231-011-0913-6

Cited by 10 publications

(5 citation statements)

References 6 publications

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“…The air injected through the orifice increases its cross-sectional area while penetrating the chamber because of the increased viscosity (laminar and turbulent). The main difference of this condition from the previous references is that J is more than ten times larger, H 0 /D is larger, and S/H 0 is slightly lower (0.077-0.333) than previous results (0.125-1) [13,14,16]. MR is equal to 0.24 and lies in the range of the published results [13].…”

Section: Experimental Methodssupporting

confidence: 58%

See 1 more Smart Citation

Penetration behavior of opposed rows of staggered secondary air jets depending on jet penetration coefficient and momentum flux ratio

Choi

et al. 2016

International Journal of Heat and Mass Transfer

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Section: Experimental Methodssupporting

confidence: 58%

“…Holdeman and Holdeman et al [13,14] summarized the nondimensional parameters that needed to be considered for designing the jet orifice at the gas turbine combustor, including the momentum flux ratio (J) and the optimum constant (C), subject to the following definitions:…”

Section: Introductionmentioning

confidence: 99%

Penetration behavior of opposed rows of staggered secondary air jets depending on jet penetration coefficient and momentum flux ratio

Choi

et al. 2016

International Journal of Heat and Mass Transfer

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“…Through the optimisation of jet hole pattern including the spacing, size and geometry: Numerous studies have been conducted to investigate the jet penetration, structure and flow field distribution resulting from jet mixing in jets in crossflow. Focused research has been conducted on single and multiple jets, bounded and unbounded [31][32][33][34][35][36][37]. Jet orifice geometries have been extensively studied and design methodology for cylindrical and rectangular configuration for a confined flow has been proposed by Cranfield to determine an optimum hole size with given momentum-flux ratio [38].…”

Section: Rich Burnmentioning

confidence: 99%

Review of modern low emissions combustion technologies for aero gas turbine engines

Liu

Sun

Sethi

et al. 2017

Progress in Aerospace Sciences

239

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Pollutant emissions from aircraft in the vicinity of airports and at altitude are of great public concern due to their impact on environment and human health. The legislations aimed at limiting aircraft emissions have become more stringent over the past few decades. This has resulted in an urgent need to develop low emissions combustors in order to meet legislative requirements and reduce the impact of civil aviation on the environment. This article provides a comprehensive review of low emissions combustion technologies for modern aero gas turbines. The review considers current high Technologies Readiness Level (TRL) technologies including Rich-Burn Quick-quench Lean-burn (RQL), Double Annular Combustor (DAC), Twin Annular Premixing Swirler combustors (TAPS), Lean Direct Injection (LDI). It further reviews some of the advanced technologies at lower TRL. These include NASA multi-point LDI, Lean Premixed Prevaporised (LPP), Axially Staged Combustors (ASC) and Variable Geometry Combustors (VGC). The focus of review is placed on working principles, a review of the key technologies (includes the key technology features, methods of realising the technology, associated technology advantages and design challenges, progress in development), technology application and emissions mitigation potential. The article concludes the technology review by providing a technology evaluation matrix based on a number of combustion performance criteria including altitude relight auto-ignition flashback, combustion stability, combustion efficiency, pressure loss, size and weight, liner life and exit temperature distribution.

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“…To address the conditions particular to applications of jets in crossflow (JIC), numerous studies have been conducted to yield insight on jet structure and penetration, jet entrainment of crossflow fluid, and the flow field distributions resulting from jet mixing [12][13][14][15][16][17][18][19][20]. These studies have investigated single unbounded jets, both bounded and unbounded multiple jets, asymmetrically bounded jets, heated jets, a heated mainflow, reacting flows, or the doping of either the jets or mainflow with a tracer to allow the measurement of scalars in the flow downstream of the jet orifices.…”

Section: Jet Mixingmentioning

confidence: 99%

“…density ratio, momentum-flux ratio, mass-flow ratio) with the goal to optimize the mixing in a gas turbine combustor. Later, the NASA JIC empirical model from [14] (without the curvature effects) was implemented in the Excel Ò spreadsheet reported in [15][16][17][18]. For rectangular, annular, or cylindrical ducts the jet spacing S/H was observed to be inversely proportion to the square root of the momentum-flux ratio J such that:…”

Section: Non-reacting Jic Mixingmentioning

confidence: 99%

Experimental and modeling investigation of the effect of air preheat on the formation of NOx in an RQL combustor

et al. 2012

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The Rich-burn/Quick-mix/Lean-burn (RQL) combustor concept has been proposed to minimize the formation of oxides of nitrogen (NO x ) in gas turbine systems. The success of this low-NO x combustor strategy is dependent upon the links between the formation of NO x , inlet air preheat temperature, and the mixing of the jet air and fuel-rich streams. Chemical equilibrium and kinetics modeling calculations and experiments were performed to further understand NO x emissions in an RQL combustor. The results indicate that as the temperature at the inlet to the mixing zone increases (due to preheating and/or operating conditions) the fuel-rich zone equivalence ratio must be increased to achieve minimum NO x formation in the primary zone of the combustor. The chemical kinetics model illustrates that there is sufficient residence time to produce NO x at concentrations that agree well with the NO x measurements. Air preheat was found to have very little effect on mixing, but preheating the air did increase NO x emissions significantly. By understanding the mechanisms governing NO x formation and the temperature dependence of key reactions in the RQL combustor, a strategy can be devised to further reduce NO x emissions using the RQL concept. List of symbolsNumber of round holes in quick-mix module R Radius of the quick-mix module r Radial distance from the module center S Orifice spacing U Axial velocity U M Unmixed mainstream velocity V J Jet exit velocity x Downstream distance; x = 0 at orifice leading edge q J Density of jet flow q M Density of mainstream flow / Equivalence ratio = (fuel/air) actual /(fuel/air) stoichiometric

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Spreadsheet calculations of jets in crossflow: opposed rows of inline and staggered round holes

Cited by 10 publications

References 6 publications

Penetration behavior of opposed rows of staggered secondary air jets depending on jet penetration coefficient and momentum flux ratio

Penetration behavior of opposed rows of staggered secondary air jets depending on jet penetration coefficient and momentum flux ratio

Review of modern low emissions combustion technologies for aero gas turbine engines

Experimental and modeling investigation of the effect of air preheat on the formation of NOx in an RQL combustor

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