scholarly journals Experimental Investigations of Superheated and Supercritical Injections of Liquid Fuels

2021 ◽  
Vol 143 (4) ◽  
Author(s):  
Zhiyao Yin ◽  
Peter Kutne ◽  
Jochen Eichhorn ◽  
Wolfgang Meier
Keyword(s):  
Pressure Drop ◽  
Thermal Effect ◽  
Elevated Temperatures ◽  
Liquid Fuels ◽  
Experimental Investigations ◽  
Fuel Vapor ◽  
Discernible Effect ◽  
The Difference ◽  
Swirl Atomizer ◽  
Pressure Swirl

Abstract Single- and multicomponent liquid fuels are injected in a jet-in-coflow configuration at elevated temperatures and pressures with both a custom plain orifice nozzle and a commercial pressure-swirl atomizer. The transitions in spray morphology from mechanical breakup to superheated/supercritical regimes are characterized qualitatively by laser shadowgraphy and evaluated based on quantitative measures of superheat. Although fuel preheating exhibits no discernible effect in the mechanical breakup regime, dramatic jet-to-plume transition as well as build-up of fuel vapor in the spray chamber is observed with increasing level of superheat. The difference between two different atomizers in terms of spray behavior diminishes at high levels of superheat, suggesting the predominant role of thermal effect on spray morphology in superheated/supercritical regimes. For a mutlicomponent fuel such as Jet A-1, the transition into a fully flashing spray occurs at temperatures lower than expected values, which are calculated by treating Jet A-1 as a single-component fuel. Additionally, pressure drop is shown as a sensitive indicator for the departure from mechanical breakup and the onset of thermal effect on the spray. Comparisons between measured and estimated pressure drop also reveal the differences in susceptibility to thermal effects between the plain orifice and the pressure-swirl atomizers.

scholarly journals Experimental Investigations of Superheated and Supercritical Injections of Liquid Fuels

2020 ◽  
Author(s):  
Zhiyao Yin ◽  
Peter Kutne ◽  
Jochen Eichhorn ◽  
Wolfgang Meier
Keyword(s):  
Pressure Drop ◽  
Thermal Effect ◽  
Elevated Temperatures ◽  
Liquid Fuels ◽  
Experimental Investigations ◽  
Fuel Vapor ◽  
Discernible Effect ◽  
The Difference ◽  
Swirl Atomizer ◽  
Pressure Swirl

Abstract Single- and multi-component liquid fuels are injected in a jet-in-coflow configuration at elevated temperatures and pressures with both a custom plain orifice nozzle and a commercial pressure-swirl atomizer. The transitions in spray morphology from mechanical breakup to superheated/supercritical regimes are characterized qualitatively by laser shadowgraphy and evaluated based on quantitative measures of superheat. Although fuel preheating exhibits no discernible effect in the mechanical breakup regime, dramatic jet-to-plume transition as well as build up of fuel vapor in the spray chamber are observed with increasing level of superheat. The difference between two different atomizers in terms of spray behavior diminishes at high levels of superheat, suggesting the predominant role of thermal effect on spray morphology in superheated/supercritical regimes. For a mutli-component fuel such as Jet A-1, the transition into a fully flashing spray occurs at temperatures lower than expected values, which are calculated by treating Jet A-1 as a single-component fuel. Additionally, pressure drop is shown as a sensitive indicator for the departure from mechanical breakup and the onset of thermal effect on the spray. Comparisons between measured and estimated pressure drop also reveal the differences in susceptibility to thermal effects between the plain orifice and the pressure-swirl atomizers.

Effects of Gravity on Rewetting of Capillary Groove Surface at Elevated Temperatures—Experimental and Theoretical Studies

1995 ◽  
Vol 117 (4) ◽  
pp. 1042-1047 ◽  
Author(s):  
S. H. Chan ◽  
J. D. Blake ◽  
T. R. Shen ◽  
Y. G. Zhao
Keyword(s):  
Elevated Temperatures ◽  
Liquid Films ◽  
Thin Liquid Films ◽  
Experimental Investigations ◽  
Plate Temperature ◽  
Groove Surface ◽  
Grooved Surface ◽  
The Difference ◽  
Experimental And Theoretical Studies ◽  
Good Agreement

Theoretical and experimental investigations of the rewetting characteristics of thin liquid films over heated and unheated capillary grooved plates were performed. To investigate the effect of gravity on rewetting, the grooved surface was placed in upward and downward-facing positions. Profound gravitational effects were observed as the rewetting velocity was found to be higher in the upward than in the downward-facing orientation. The difference was even greater with higher initial plate temperatures. With either orientation, it was found that the rewetting velocity increased with the initial plate temperature. But when the temperature was raised above a rewetting temperature, the rewetting velocity decreased with the initial plate temperature. Hydrodynamically controlled and heat conduction controlled rewetting models were then presented to explain and to predict the rewetting characteristics in these two distinct regions. The predicted rewetting velocities were found to be in good agreement with experimental data with elevated plate temperatures.

Experimental Investigation on Ignition Performance of LESS Combustor

2011 ◽  
Author(s):  
Zhenbo Fu ◽  
Yuzhen Lin ◽  
Jibao Li ◽  
Chih-Jen Sung
Keyword(s):  
Pressure Drop ◽  
Flow Field ◽  
Civil Aviation ◽  
Inlet Temperature ◽  
Reacting Flow ◽  
Main Stage ◽  
Minor Effect ◽  
Swirl Atomizer ◽  
Pressure Swirl ◽  
Pressure Swirl Atomizer

In the design of next-generation civil aviation gas turbine combustors, there is high demand to improve the efficiency of combustion technology to decrease the amount of fuel consumed and to reduce the emissions in an effort to lessen the environmental impacts. This paper introduces a novel, ultra-low emissions combustor, namely Low Emission Stirred Swirl (LESS) combustor, employing the lean premixed prevaporized (LPP) approach. The LESS combustor is a single annular layout. Its dome is comprised of two stages — the pilot stage and the main stage. The pilot stage is a typical swirl cup design which uses a pressure swirl atomizer with dual counter-rotating radial swirlers to atomize the fuel and form a diffusion flame, and is located in the centerline of the combustion chamber. The main stage surrounding coaxially the pilot stage includes one annulus as premixer and 14 plain orifice atomizers with 14 small dual counter-rotating radial swirlers arranged uniformly on the dome of the annulus, which lead to the main premixed flame. Five different igniter locations are chosen according to the CFX-simulated non-reacting flow field of a simplified mainstage combustor. Only the pilot pressure swirl atomizer is operated in the present ignition performance tests. The model combustor is a single module rectangular combustor with normal inlet temperature and normal inlet pressure. Under the test conditions of air pressure drop of 0.5%–9%, the ignition performance of the model LESS combustor is analyzed. The lean lightoff fuel/air ratio (LLO FAR), characterizing the ignition performance of a combustor, is investigated herein. In addition, the effects of igniter locations and pilot fuel nozzles on LLO FAR are studied. Specific to the LESS combustor, the igniter location has minor effect on the LLO FAR values. However, as expected, the combustor dome pressure drop and attendant reference velocity along with spray SMD impact LLO FAR. Furthermore, CFX-simulated results of the flow field, spray characteristics, and gas-liquid interactions under the typical condition of combustor operation are presented and discussed to provide insight into the ignition processes and performance.

Pressure-Scaling of Pressure-Swirl Atomizer Cone Angles

2006 ◽  
Author(s):  
D. R. Guildenbecher ◽  
R. R. Rachedi ◽  
P. E. Sojka
Keyword(s):  
Pressure Drop ◽  
Ambient Pressure ◽  
Cone Angle ◽  
Subsequent Increase ◽  
Gas Entrainment ◽  
A Value ◽  
Swirl Atomizer ◽  
Pressure Swirl ◽  
Pressure Swirl Atomizer ◽  
Measure Cone

An experimental investigation was conducted to study the effects of increased ambient pressure (up to 6.89 MPa) and increased nozzle pressure drop (up to 2.8 MPa) on the cone angles for sprays produced by pressure-swirl atomizers having varying amounts of initial swirl. This study extends the classical results of DeCorso and Kemeny [1]. Shadow photography was used to measure cone angles at x/D0=10, 20, 40, and 60. Our lower pressure results for atomizer swirl numbers of 0.50 and 0.25 are consistent with those of DeCorso and Kemeny [1], who observed a decrease in cone angle with an increase in a pressure drop-ambient density product until a minimum cone angle was reached at ΔPρair1.6~200. Results for atomizers having higher swirl numbers do not match the DeCorso and Kemeny [1] results as well, suggesting that their correlation be used with caution. Another key finding is that an increase in ΔPρair1.6 to a value of 1000 leads to continued decreases in cone angle, but that a subsequent increase to 4000 has little effect on cone angle. Finally, there was little influence of atomizer pressure drop on cone angle, in contrast to findings of previous workers. These effects are hypothesized to be due to gas entrainment.

Experimental investigations of spray generated by a pressure swirl atomizer

2019 ◽  
Vol 92 (2) ◽  
pp. 210-221 ◽  
Author(s):  
Cunxi Liu ◽  
Fuqiang Liu ◽  
Jinhu Yang ◽  
Yong Mu ◽  
Chunyan Hu ◽  
...  
Keyword(s):  
Experimental Investigations ◽  
Swirl Atomizer ◽  
Pressure Swirl ◽  
Pressure Swirl Atomizer

Experimental Investigations of Performance Parameters of Pressure Swirl Atomizer for Kerosene Type Fuel

2009 ◽  
Author(s):  
Saurabh Dikshit ◽  
Salim Channiwala ◽  
Digvijay Kulshreshtha ◽  
Kamlesh Chaudhari
Keyword(s):  
Drop Size ◽  
Mechanical Energy ◽  
Cone Angle ◽  
Experimental Investigations ◽  
Performance Parameters ◽  
Spray Cone ◽  
Spray Penetration ◽  
Swirl Atomizer ◽  
Pressure Swirl ◽  
Pressure Swirl Atomizer

The process of atomization is one in which a liquid jet or sheet is disintegrated by the kinetic energy of the liquid itself, or by exposure to high velocity air or gas, or as a result of mechanical energy applied externally. Combustion of liquid fuels in engines and industrial furnaces is dependent on effective atomization to increase the specific surface area of the fuel and thereby achieve high rate of mixing and evaporation. The pressure swirl atomizer is most common type atomizer used for combustion in gas turbine engines and industrial furnaces. The spray penetration is of prime importance for combustion designs. Over penetration of the spray leads to impingement of the fuel on walls of furnaces and combustors. On the other hand, if spray penetration is inadequate, fuel–air mixing is unsatisfactory. Optimum engine performance is obtained when the spray penetration is matched to the size and geometry of combustors. Methods for calculating penetration are therefore essential to sound engine design. Equally important are the spray cone angles and the drop size distribution in the sprays. An attempt is being made to experimentally investigate pressure swirl atomizer performance parameters such as spray cone angle, penetration length and drop size at different injection pressures ranging from 6 bar to 18 bar.

Pressure-Scaling of Pressure-Swirl Atomizer Cone Angles

2008 ◽  
Vol 130 (6) ◽  
Author(s):  
D. R. Guildenbecher ◽  
R. R. Rachedi ◽  
P. E. Sojka
Keyword(s):  
Pressure Drop ◽  
Ambient Pressure ◽  
Cone Angle ◽  
Spray Angle ◽  
Subsequent Increase ◽  
A Value ◽  
Nozzle Pressure ◽  
Swirl Atomizer ◽  
Pressure Swirl ◽  
Pressure Swirl Atomizer

An experimental investigation was conducted to study the effects of increased ambient pressure (up to 6.89MPa) and increased nozzle pressure drop (up to 2.8MPa) on the cone angles for sprays produced by pressure-swirl atomizers having varying amounts of initial swirl. This study extends the classical results of DeCorso and Kemeny, (1957, “Effect of Ambient and Fuel Pressure on Nozzle Spray Angle,” ASME Transactions, 79(3), pp. 607–615). Shadow photography was used to measure cone angles at x∕D0=10, 20, 40, and 60. Our lower pressure results for atomizer swirl numbers of 0.50 and 0.25 are consistent with those of DeCorso and Kemeny, who observed a decrease in cone angle with an increase in nozzle pressure drop, ΔP, and ambient density, ρair, until a minimum cone angle was reached when ΔPρair1.6∼100MPa(kg∕m3)1.6 (equivalent to 200psi(lbm∕ft3)1.6). Results for atomizers having higher initial swirl do not match the DeCorso and Kemeny results as well, suggesting that their correlation be used with caution. Another key finding is that an increase in ΔPρair1.6 to a value of 600MPa(kg∕m3)1.6 leads to continued decrease in cone angle, but that a subsequent increase to 2000MPa(kg∕m3)1.6 has little effect on cone angle. Finally, there was little effect of nozzle pressure drop on cone angle, in contrast to findings of previous workers. These effects are hypothesized to be due to gas entrainment.

INTERNAL AND NEAR-NOZZLE FLOW OF A PRESSURE-SWIRL ATOMIZER UNDER VARIED FUEL TEMPERATURE

2007 ◽  
Vol 17 (6) ◽  
pp. 529-550 ◽  
Author(s):  
Seoksu Moon ◽  
Choongsik Bae ◽  
Essam F. Abo-Serie ◽  
Jaejoon Choi
Keyword(s):  
Nozzle Flow ◽  
Fuel Temperature ◽  
Swirl Atomizer ◽  
Pressure Swirl ◽  
Pressure Swirl Atomizer

Study of pressure swirl atomizer with tangential input at design point and outside of design point

2020 ◽  
Vol 32 (12) ◽  
pp. 127113
Author(s):  
Kiumars Khani Aminjan ◽  
Balaram Kundu ◽  
D. D. Ganji
Keyword(s):  
Design Point ◽  
Swirl Atomizer ◽  
Pressure Swirl ◽  
Pressure Swirl Atomizer
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