scholarly journals Wavelet analysis of flame blowout of a liquid-fueled swirl burner with quarls

2019 ◽  
Vol 67 (5) ◽  
pp. 394-403
Author(s):  
Viktor Józsa ◽  
Gergely Novotni
Keyword(s):  
Wavelet Transformation ◽  
Acoustic Noise ◽  
Operating Regime ◽  
Pollutant Emissions ◽  
Swirl Number ◽  
Axial Thrust ◽  
Lean Blowout ◽  
Swirl Combustion ◽  
Thrust Control ◽  
Flame Shape

Lean swirl combustion is the leading burner concept today, used in several steadyoperating applications to ensure awide operating range and low pollutant emissions. Approaching lean blowout is highly desired by design to achieve the lowest possible NOX emission. It was shown earlier that quarls could significantly extend the operating regime of liquid-fueled swirl burners. In the present study, the accompanying acoustic noise is evaluated by continuous wavelet transformation to show the effect of various quarl geometries on lean flame blowout. However, the desired flame shape of swirl burners is V, first, and a straight flame, and then a transitory regime can be observed before the developed V-shaped flame through increasing the swirl number. If the axial thrust is excessive, blowout might occur in earlier stages. Presently, the characteristic bands before blowout were analyzed and evaluated at various quarl geometries, swirl numbers, and atomizing pressures. The latter parameter also acts as an axial thrust control to adjust the swirl number. firstly, a straight flame, then a transitory regime can be observed before the developed V-shaped flame through increasing the swirl number. If the axial thrust is excessive, blowout might occur in earlier stages. Presently, the characteristic bands before blowout were analyzed and evaluated at various quarl geometries, swirl numbers, and atomizing pressures. The latter parameter also acts as an axial thrust control to adjust the swirl number.

scholarly journals Swirler geometry effects (dh/do ratio) on synthetic gas flames: Part 1: Combustion and emission characteristics

Energetika ◽  
2021 ◽  
Vol 67 (1) ◽  
Author(s):  
Harun Yilmaz ◽  
Omer Cam ◽  
Ilker Yilmaz
Keyword(s):  
Room Temperature ◽  
Swirling Flow ◽  
Pollutant Emissions ◽  
Emission Characteristics ◽  
Atmospheric Conditions ◽  
Data Logger ◽  
Swirl Number ◽  
Synthetic Gas ◽  
Performance Results ◽  
The City

Swirling flows increase combustion performance via favouring flame stability, pollutant emissions, and combustion intensity. The strength of a swirling flow is characterized by a parameter known as swirl number, which is highly related to the dh/do ratio. In this study, effects of the swirler dh/do ratio on combustion and emission characteristics of the synthetic gas flames of premixed 20%CNG/30%H2/30%CO/20%CO2 mixture were experimentally investigated in a laboratory-scale swirl stabilized combustor. For this purpose, twelve different swirl generators were designed and manufactured. dh/do ratios of these swirlers were set as 0.30 and 0.50, and the geometric swirl number was varied between the values of 0.4 and 1.4 (at 0.2 intervals). All experiments were conducted at a fuel-lean equivalence ratio (ϕ = 0.6), room temperature, and local atmospheric conditions of the city of Kayseri, Turkey. A data logger was utilized to plot axial and radial temperatures and NOx, CO, and CO2 profiles, which were exploited to assess combustion and emission performance. Results showed that the dh/do ratio had a non-monotonic effect on the behaviour of combustion and emission of the tested synthetic gas mixture. Depending on the swirl number, increments and decrements were observed in temperature and emission values.

scholarly journals Experimental Investigation of Cycle Properties, Noise, and Air Pollutant Emissions of an APS3200 Auxiliary Power Unit

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Teresa Siebel ◽  
Jan Zanger ◽  
Andreas Huber ◽  
Manfred Aigner ◽  
Karsten Knobloch ◽  
...  
Keyword(s):  
Power Unit ◽  
Acoustic Noise ◽  
Air Pollutant ◽  
Pollutant Emissions ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Noise Emission ◽  
Auxiliary Power Unit ◽  
Auxiliary Power ◽  
Power Load

Auxiliary power unit (APU) operators face increasingly stricter airport requirements concerning exhaust gas and noise emission levels. To simultaneously reduce exhaust gas and noise emissions and to satisfy the increasing demand of electric power on board, optimization of the current technology is necessary. Prior to any possible demonstration of optimization potential, detailed data of thermodynamic properties and emissions have to be determined. Therefore, the investigations presented in this paper were conducted at a full-scale APU of an operational aircraft. A Pratt & Whitney (East Hartford, CT) APS3200, commonly installed in the Airbus A320 aircraft family, was used for measurements of the reference data. In order to describe the APS3200, the full spectrum of feasible power load and bleed air mass flow combinations were adjusted during the study. Their effect on different thermodynamic and performance properties, such as exhaust gas temperature, pressure as well as electric and overall efficiency is described. Furthermore, the mass flows of the inlet air, exhaust gas, and fuel input were determined. Additionally, the work reports the exhaust gas emissions regarding the species CO2, CO, and NOx as a function of load point. Moreover, the acoustic noise emissions are presented and discussed. With the provided data, the paper serves as a database for validating numerical simulations and provides a baseline for current APU technology.

Axial Thrust Control of High-speed Centrifugal Pump with Cavity Vanes

2012 ◽  
Vol 15 (6) ◽  
pp. 46-50 ◽  
Author(s):  
Dae-Jin Kim ◽  
Chang-Ho Choi ◽  
Jun-Gu Noh ◽  
Jinhan Kim
Keyword(s):  
Centrifugal Pump ◽  
High Speed ◽  
Axial Thrust ◽  
Thrust Control

Experimental Investigation of Cycle Properties, Noise and Air Pollutant Emissions of an APS3200 Auxiliary Power Unit

2017 ◽  
Author(s):  
Teresa Siebel ◽  
Jan Zanger ◽  
Andreas Huber ◽  
Manfred Aigner ◽  
Karsten Knobloch ◽  
...  
Keyword(s):  
Power Unit ◽  
Acoustic Noise ◽  
Air Pollutant ◽  
Pollutant Emissions ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Noise Emission ◽  
Auxiliary Power Unit ◽  
Auxiliary Power ◽  
Power Load

Auxiliary power unit (APU) operators face increasingly stricter airport requirements concerning exhaust gas and noise emission levels. To simultaneously reduce exhaust gas and noise emissions and to satisfy the increasing demand of electric power on board, optimization of the current technology is necessary. Prior to any possible demonstration of optimization potential, detailed data of thermodynamic properties and emissions have to be determined. Therefore, the investigations presented in this paper were conducted at a full-scale APU of an operational aircraft. A Pratt & Whitney APS3200, commonly installed in the Airbus A320 aircraft family, was used for measurements of the reference data. In order to describe the APS3200, the full spectrum of feasible power load and bleed air mass flow combinations were adjusted during the study. Their effect on different thermodynamic and performance properties, such as exhaust gas temperature, pressure as well as electric and overall efficiency is described. Furthermore, the mass flows of the inlet air, exhaust gas and fuel input were determined. Additionally, the work reports the exhaust gas emissions regarding the species CO2, CO and NOx as a function of load point. Moreover the acoustic noise emissions are presented and discussed. With the provided data the paper serves as a database for validating numerical simulations and provides a baseline for current APU technology.

Predicting Lean Blowout and Emissions of Aircraft Engine Combustion Chamber Based on CRN

2019 ◽  
Vol 36 (2) ◽  
pp. 147-156 ◽  
Author(s):  
Yinli Xiao ◽  
Zhengxin Lai ◽  
Zupeng Wang ◽  
Kefei Chen
Keyword(s):  
Combustion Chamber ◽  
Initial Conditions ◽  
Aircraft Engine ◽  
Chemical Reactor ◽  
Pollutant Emissions ◽  
Chemical Mechanism ◽  
Lean Blowout ◽  
Operating Modes ◽  
Engine Combustion ◽  
Set Up

Abstract To predict the pollutant emissions and lean blowout, chemical reactor network (CRN) model is applied to the modern aircraft engine combustion chamber. In this study, the CRN which represent the major features of aerodynamics and combustion in the combustion chamber is set up based on the OpenFOAM simulation results. The boundary and the initial conditions used for the CRN derive from the operating modes of typical aircraft engine cycle. A 21 species 30 steps chemical mechanism of kerosene is employed in the CRN method. The levels of pollutant emissions are obtained under four ICAO engine power settings of idle, approach climb and take off. The lean blowout equivalent ratio is evaluated at the idle power setting. The results will be helpful to predict the aircraft engine exhaust emissions and lean blowout (LBO).

scholarly journals Conceptual Studies of a Fuel-Flexible Low-Swirl Combustion System for the Gas Turbine in Clean Coal Power Plants

2010 ◽  
Author(s):  
Kenneth O. Smith ◽  
Peter L. Therkelsen ◽  
David Littlejohn ◽  
Sy Ali ◽  
Robert K. Cheng
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Fuel Injection ◽  
Pollutant Emissions ◽  
Injection System ◽  
Combustion System ◽  
High Hydrogen ◽  
Swirl Combustion ◽  
Auto Ignition

This paper reports the results of preliminary analyses that show the feasibility of developing a fuel flexible (natural gas, syngas and high-hydrogen fuel) combustion system for IGCC gas turbines. Of particular interest is the use of Lawrence Berkeley National Laboratory’s DLN low swirl combustion technology as the basis for the IGCC turbine combustor. Conceptual designs of the combustion system and the requirements for the fuel handling and delivery circuits are discussed. The analyses show the feasibility of a multi-fuel, utility-sized, LSI-based, gas turbine engine. A conceptual design of the fuel injection system shows that dual parallel fuel circuits can provide range of gas turbine operation in a configuration consistent with low pollutant emissions. Additionally, several issues and challenges associated with the development of such a system, such as flashback and auto-ignition of the high-hydrogen fuels, are outlined.

Scaling Thermo-Acoustic Characteristics of LP and LPP Swirl Flames

2007 ◽  
Author(s):  
Michael Russ ◽  
Axel Meyer ◽  
Horst Bu¨chner
Keyword(s):  
Gas Turbine ◽  
Transfer Functions ◽  
Burning Velocity ◽  
Pollutant Emissions ◽  
Operating Pressure ◽  
Swirl Number ◽  
Frequency Dependent ◽  
Lean Premixed ◽  
Operation Parameters ◽  
Main Operation

One of the main objectives of combustion research in field of gas turbine application during the last decades was and still is the reduction of pollutant emissions. The most promising technology to reduce these pollutants turned out to be Lean Premixed (LP) and Lean Premixed Pre-Vaporized (LPP) combustion. However, serious problems concerning combustion-driven instabilities occurred with the implementation of the LP/LPP-concept. Today, prediction and systematic suppression of self-sustained combustion instabilities is an issue still unsolved, due to incomplete understanding of the physical feedback mechanism and the lack of models for dynamic flame response, i.e. frequency dependent characteristics of LP/LPP swirl flames. In that context, the purpose of the current paper is the establishment of a physical model to describe frequency dependent flame dynamics concerning burning velocity of steady-state premixed flames. Derived from that basic understanding, scaling laws for the prediction of unstable operation conditions will be established in dependence on main operation parameters such as thermal load, mixture temperature, air equivalence ratio and especially of fuel and operating pressure. Therefore, a new swirl-burner has been designed, offering the feasibility to choose the type of fuel, to adjust the swirl number for main and pilot burner and the burner exit geometry steplessly and to vary preheating temperatures, air equivalence ratios and thermal loads in a range of industrial relevance for gas turbine applications. To establish a periodical modulation of the mixture mass flow of the main L(P)P flame at the burner outlet sinusoidally in-time with well-defined frequencies and amplitudes, a pulsating unit was used. Using a mixing/ pre-vaporizing unit to create a time-independent and spatial homogeneous mixture of natural gas/ kerosene vapor and combustion air at the burner outlet, flame transfer functions of LP- and LPP swirl flames depending on main operating parameters were determined. The discussed results then lead to stability map for a given combustion system depending on the main operation parameters based on the knowledge of only one fully-described parameter combination leading to an instable condition. Based on this scaling procedure and confirmed by further experimental work the prediction of stability limits depending especially on the type of fuel, the swirl number and the operating pressure will be possible.

scholarly journals An Investigation on Flame Shape and Size for a High-Pressure Turbulent Non-Premixed Swirl Combustion

Energies ◽  
2018 ◽  
Vol 11 (4) ◽  
pp. 930 ◽  
Author(s):  
Zhongya Xi ◽  
Zhongguang Fu ◽  
Xiaotian Hu ◽  
Syed Sabir ◽  
Yibo Jiang
Keyword(s):  
High Pressure ◽  
Swirl Combustion ◽  
Flame Shape ◽  
Shape And Size

Side Thrust Control by Secondary Gas Injection into Rocket Nozzles

1968 ◽  
Vol 10 (3) ◽  
pp. 239-251 ◽  
Author(s):  
J. H. Neilson ◽  
A. Gilchrist ◽  
C. K. Lee
Keyword(s):  
Secondary Flows ◽  
Axial Thrust ◽  
Side Force ◽  
Axial Location ◽  
Force Transducers ◽  
Directional Control ◽  
Constant Diameter ◽  
Supersonic Region ◽  
Thrust Control ◽  
Secondary Port

Directional control of rockets can be achieved by using secondary gas jets for providing side forces. The present investigation is concerned with the fact that a greater side force can be achieved by expanding the secondary gas into the supersonic region of the main nozzle than by expanding it directly to atmosphere. A laboratory test rig using ambient temperature air for the primary and secondary flows is described. Axial thrust and side force were measured using strain gauge force transducers. The experiments were performed on a small axisymmetric main nozzle with a 10° semi-angle of divergence and with sonic injection through circular ports placed normal to the main nozzle axis. The investigations centred principally on the effects of (1) varying the secondary port size at a given axial location in the nozzle and of (2) varying the axial location of a port of constant diameter. Side force and axial thrust augmentation characteristics were obtained for a range of primary and secondary flow inlet pressures. The results show the relative importance of the parameters on which side force depends, the maximum side force that may be produced and the interdependence of axial thrust augmentation and side force.

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