scholarly journals Experiment Study of Ignition Characteristics in An Axial-flow-injector Burner for Stirling Engine

2021 ◽  
Vol 313 ◽  
pp. 11002
Author(s):  
Liu Kun ◽  
Lu Tian ◽  
Lan Jian ◽  
Huang Xiaoyu ◽  
Yin Guofeng
Keyword(s):  
Combustion Chamber ◽  
Oxygen Supply ◽  
Ignition Time ◽  
Axial Flow ◽  
Stirling Engine ◽  
Oxygen Flow Rate ◽  
Chamber Pressure ◽  
Injection Burner ◽  
Ignition Characteristics ◽  
Supply Time

To investigate the ignition characteristics of an axial-flow injection burner for a Stirling engine, a combustion chamber was designed. Diesel was used as fuel and oxygen as oxidant. The experiments of ignition characteristics were carried out with an electric plug igniter. The ignition characteristics under different combustion chamber pressure, pre-oxygen supply time, oxygen supply flow and ignition position were studied. The experimental results show that, with the increase of the pressure, the ignition time of the burner increases gradually, and the ignition success rate decreases gradually. The oxygen flow rate is related to ignition time in a certain range, while the pre-oxygen supply time has little effect. With the ignition position moving downward, the ignition time decreases gradually.

Evaluation of Combustion Chamber Pressure of 1N-Class Green Monopropellant Thruster with Discharge Plasma System

2017 ◽  
Vol 65 (3) ◽  
pp. 117-122
Author(s):  
Asato WADA ◽  
Hiroshi MAEDA ◽  
Takahiro SHINDO ◽  
Hiroki WATANABE ◽  
Haruki TAKEGAHARA
Keyword(s):  
Combustion Chamber ◽  
Discharge Plasma ◽  
Chamber Pressure ◽  
Plasma System

Preliminary Studies on Non-Reactive Flow Vortex Cooling

2019 ◽  
Vol 12 (3) ◽  
pp. 262-271
Author(s):  
T.N. Rajesh ◽  
T.J.S. Jothi ◽  
T. Jayachandran
Keyword(s):  
Combustion Chamber ◽  
Inner Core ◽  
Rocket Engine ◽  
Injection Pressure ◽  
Chamber Pressure ◽  
Reactive Flow ◽  
Stoichiometric Ratio ◽  
Gaseous Oxygen ◽  
Mixture Ratio ◽  
Vortex Combustion

Background: The impulse for the propulsion of a rocket engine is obtained from the combustion of propellant mixture inside the combustion chamber and as the plume exhausts through a convergent- divergent nozzle. At stoichiometric ratio, the temperature inside the combustion chamber can be as high as 3500K. Thus, effective cooling of the thrust chamber becomes an essential criterion while designing a rocket engine. Objective: A new cooling method of thrust chambers was introduced by Chiaverni, which is termed as Vortex Combustion Cold-Wall Chamber (VCCW). The patent works on cyclone separators and confined vortex flow mechanism for providing high propellant mixing with improved degree of turbulence inside the combustion chamber, providing the required notion for studies on VCCW. The flow inside a VCCW has a complex structure characterised by axial pressure losses, swirl velocities, centrifugal force, flow reversal and strong turbulence. In order to study the flow phenomenon, both the experimental and numerical investigations are carried out. Methods: In this study, non-reactive flow analysis was conducted with real propellants like gaseous oxygen and hydrogen. The test was conducted to analyse the influence of mixture ratio and injection pressure of the propellants on the chamber pressure in a vortex combustion chamber. A vortex combustor was designed in which the oxidiser injected tangentially at the aft end near the nozzle spiraled up to the top plate and formed an inner core inside the chamber. The fuel was injected radially from injectors provided near the top plate and the propellants were mixed in the inner core. This resulted in enhanced mixing and increased residence time for the fuel. More information on the flow behaviour has been obtained by numerical analysis in Fluent. The test also investigated the sensitivity of the tangential injection pressure on the chamber pressure development. Results: All the test cases showed an increase in chamber pressure with the mixture ratio and injection pressure of the propellants. The maximum chamber pressure was found to be 3.8 bar at PC1 and 2.7 bar at PC2 when oxidiser to fuel ratio was 6.87. There was a reduction in chamber pressure of 1.1 bar and 0.7 bar at PC1 and PC2, respectively, in both the cases when hydrogen was injected. A small variation in the pressure of the propellant injected tangentially made a pronounced effect on the chamber pressure and hence vortex combustion chamber was found to be very sensitive to the tangential injection pressure. Conclusion: VCCW mechanism has been to be found to be very effective for keeping the chamber surface within the permissible limit and also reducing the payload of the space vehicle.

The flame behaviour of liquefied petroleum gas spray impinging on a flat plate in a constant volume combustion chamber

2005 ◽  
Vol 219 (5) ◽  
pp. 655-663 ◽  
Author(s):  
Kweonha Park
Keyword(s):  
Combustion Chamber ◽  
Ambient Pressure ◽  
Constant Volume ◽  
Chamber Pressure ◽  
Cylinder Wall ◽  
Liquefied Petroleum Gas ◽  
Wide Range ◽  
Constant Volume Combustion ◽  
Constant Volume Combustion Chamber ◽  
Ignition Site

Liquefied petroleum gas (LPG) sprays and diffusion flames are investigated in a constant volume combustion chamber having an impingement plate. The spray and flame images are visualized and compared with diesel and gasoline images over a wide range of ambient pressure. The high-speed digital camera is used to take the flame images. The injection pressure is generated by a Haskel air-driven pump, and the initial chamber pressure is adjusted by the amount of pumping air. The LPG spray and flame photographs are compared with those of gasoline and diesel fuel at the same conditions, and then the spray and flame development behaviour is analysed. The spray photographs show that the dispersion characteristics of LPG spray are sensitive to the ambient pressure. In a low initial chamber pressure LPG fuel in the liquid phase evaporates quickly and does not reach down easily to the impinging plate having a hot coil for ignition. That makes the temperature and equivalence ratio low near the ignition coil, thus making ignition diffcult. On the other hand, in a high initial chamber pressure the spray leaving the nozzle gathers around the ignition site after impinging on the plate, which makes an intense flame near the plate. If applied to small-sized direct injection engines that are not able to avoid spray impinging on a cylinder wall, LPG will have faster and cleaner combustion than diesel or gasoline fuels. However, the chamber geometry should be carefully designed to enable a sufficient amount of vaporized fuel to get to the ignition site

scholarly journals Flow field and species concentration measurements in the primary zone of an aero-engine combustion chamber

2018 ◽  
Vol 10 (1) ◽  
pp. 168781401774805
Author(s):  
Yinli Xiao ◽  
Zupeng Wang ◽  
Zhengxin Lai ◽  
Kefei Chen ◽  
Wenyan Song
Keyword(s):  
Flow Field ◽  
Combustion Chamber ◽  
Operating Conditions ◽  
Chamber Pressure ◽  
Species Concentration ◽  
Primary Zone ◽  
Major Species ◽  
Engine Combustion ◽  
Aero Engine ◽  
Concentration Measurements

The principal features of primary zone determine the performance parameters of the whole combustion chamber, such as the pollutant emissions and combustion efficiency. In this work, flow field and major species concentration measurements are conducted in the primary zone of an aero-engine combustion chamber. The operating conditions such as air inlet temperature, chamber pressure, and air-to-fuel ratio are chosen to replicate the realistic operating conditions. The velocity field and streamlines are obtained by particle imaging velocimetry technology. The concentrations of major species are acquired by a spontaneous Raman scattering system. This article validates the feasibility of two laser diagnostic measurement techniques and presents the initial results under realistic aero-engine conditions.

Design, Evaluation and Performance Analysis of Staged Low Emission Combustors

2012 ◽  
Author(s):  
Gajanana B. Hegde ◽  
Bhupendra Khandelwal ◽  
Vishal Sethi ◽  
Riti Singh
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Design Methodology ◽  
Reverse Flow ◽  
Axial Flow ◽  
Design Procedure ◽  
Extensive Study ◽  
Theoretical Design ◽  
Low Emission ◽  
And Performance

The most uncertain and challenging part in the design of a gas turbine has long been the combustion chamber. There has been large number of experimentations in industries and universities alike to better understand the dynamic and complex processes that occur inside a combustion chamber. This study concentrates on gas turbine combustors as a whole, and formulates a theoretical design procedure for staged combustors in particular. Not much of literatures available currently in public domain provide intensive study on designing staged combustors. The work covers an extensive study of design methods applied in conventional combustor designs, which includes the reverse flow combustor and the axial flow annular combustors. The knowledge acquired from this study is then applied to develop a theoretical design methodology for double staged (radial and axial) low emission annular combustors. Additionally a model combustor is designed for each type; radial and axial staging using the developed methodology. A prediction of the performance for the model combustors is executed. The main conclusion is that the dimensions of model combustors obtained from the developed design methodology are within the feasibility limits. The comparison between the radially staged and the axially staged combustor has yielded the predicted results such as lower NOx prediction for the latter and shorter combustor length for the former. The NOx emission result of the new combustor models are found to be in the range of 50–60ppm. However the predicted NOx results are only very crude and need further detailed study.

The Development of an Axial Flow Gas Turbine for Jet Propulsion

1947 ◽  
Vol 157 (1) ◽  
pp. 471-482 ◽  
Author(s):  
D. M. Smith
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Axial Flow ◽  
Bench Test ◽  
Jet Propulsion ◽  
Flow Type ◽  
Company Limited ◽  
Flow Compressor ◽  
Main Component

The paper reviews the technical development of the F2 jet propulsion engine, an axial flow gas turbine designed and manufactured by the Metropolitan-Vickers Electrical Company, Limited, under contract from the Ministry of Aircraft Production. An account is given of the preliminary work in 1938–9, in collaboration with the Royal Aircraft Establishment, on gas turbines for aircraft propulsion. The development of a simple jet engine of the axial flow type was started in July 1940. The first engine ran on bench test in December 1941. The first flights took place in June 1943 on a flying testbed, and in November 1943 on a jet-propelled aircraft. The evolution of engines of this type, leading up to the current F2/4 jet propulsion engine, is described. Each main component of the engine—the axial flow compressor, the annular combustion chamber and the high temperature turbine—necessitated extensive development work in fields previously unexplored; the methods used in the development of these and other components are explained. The F2 engine was the first British jet propulsion engine of axial flow type, and it is also unique amongst British engines in the straight-through design and annular combustion chamber that gives an exceptionally low frontal area.

scholarly journals Experimental Study on Diesel Spray Characteristics and Autoignition Process

2011 ◽  
Vol 2011 ◽  
pp. 1-20 ◽  
Author(s):  
Özgür Oğuz Taşkiran ◽  
Metin Ergeneman
Keyword(s):  
High Speed ◽  
Ignition Time ◽  
Cetane Number ◽  
Ccd Camera ◽  
Nozzle Geometry ◽  
Diesel Spray ◽  
Macroscopic Properties ◽  
Constant Volume Combustion Chamber ◽  
Nozzle Geometries ◽  
Ignition Characteristics

The main goal of this study is to get the temporal and spatial spray evolution under diesel-like conditions and to investigate autoignition process of sprays which are injected from different nozzle geometries. A constant volume combustion chamber was manufactured and heated internally up to 825 K at 3.5 MPa for experiments. Macroscopic properties of diesel spray were recorded via a high-speed CCD camera by using shadowgraphy technique, and the images were analyzed by using a digital image processing program. To investigate the influence of nozzle geometry, 4 different types of divergent, straight, straight-rounded, convergent-rounded nozzles, were manufactured and used in both spray evolution and autoignition experiments. The internal geometry of the injector nozzles were obtained by using silicone mold method. The macroscopic properties of the nozzles are presented in the study. Ignition behaviour of different nozzle types was observed in terms of ignition delay time and ignition location. A commercial Diesel fuel,n-heptane, and a mixture of hexadecane-heptamethylnonane (CN65—cetane number 65) were used as fuels at ignition experiments. The similar macroscopic properties of different nozzles were searched for observing ignition time and ignition location differences. Though spray and ignition characteristics revealed very similar results, the dissimilarities are presented in the study.

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