• Journal of the Korean Society of Safety
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• 제8권3호
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• pp.19-25
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• 1993

This paper deals with the experimental study of the turbulent characteristics in the swirling coaxial Jets. In this research, the experimental study has been carried out to investigate the effects of swirl number and equivalence ratio on the flow characteristics in nonreacting flow field of the model combustor which symplifys the continuous type combustor for the practical use. Author particularly Intends to find out the fuel-air mixing In the recirculation zone In order to make sure the effects of swirl number and equivalence ratio on the stabilization of flame.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 한국추진공학회 2008년 영문 학술대회
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• pp.63-65
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• 2008

CFD cold-flow analysis results of the air-blast swirl nozzle for the small aircraft engine combustor are shown. Two major recirculation zones are observed near the nozzle. The centerline recirculation zone velocity profile of CFD is compared with the experimental results.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 한국추진공학회 2005년도 제25회 추계학술대회논문집
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• pp.335-340
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• 2005

A study on the variation of combustion characteristics by injector geometries was conducted. Coaxial swirl injectors were used. Existence of swirl chamber and variation of a nozzle length become key parameters. Injectors were identified as open, closed and mixed type by existence of swirl chamber. Variation of nozzle length was made extruding the both nozzle along the axis while other design parameters remain the same. A uni-element combustor with ablative material liner and a water cooled nozzle made by oxygen free copper with outer stainless steel casing were used.

• Transactions of the Korean Society of Mechanical Engineers B
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• 제22권6호
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• pp.840-848
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• 1998

The preliminary design and performance test were carried out for determining dimensions of gas turbine combustor. The combustor design program was developed and applied to design our combustor, and the specific dimensions for swirler, dome and liner holes were determined by the semiempirical manner. Based on the first performance test data, the swirl angle governing the combustion characteristics of primary combustor zone was determined as 40 deg.. Using the second performance test data, the swirler dimensions were readjusted by 24 mm i.d., 34 mm o.d., and swirl angle of 45 deg.. The geometry of liner holes were determined by considering the flame stability and recirculation zone size. It was found that flame can be more easily stabilized by adjusting the swirler dimensions rather than liner holes. The geometry of swirler and liner holes were readjusted by using the final performance test data with dilution holes. Also, the combustor performance and emission characteristics were evaluated by analysis of exhaust gases.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 한국추진공학회 2009년도 춘계학술대회 논문집
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• pp.263-266
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• 2009

The mainly objectives of this study was a combustion dynamics and instability characteristics in a model gas turbine dump combustor which is the scale down of GE 7FA+e DLN 2.6 gas turbine combustor. Model gas turbine injector has 2-stage swirl vane and it’s reduced 1/3 size of the original one. The shape of plenum and combustor were designed for similar acoustic characteristics. Inlet air was preheated to $200{\sim}400^{\circ}C$. The flow velocity at mixing nozzle was 30 to 75 m/s and equivalent ratio was 0.4 to 1.2. The combustor length was varied for different acoustic characteristics to $375{\sim}700\;mm$. As the result, this research have been show the combustion instability was observed at lower equivalence ratios ($\Phi$ < $0.5{\sim}0.6$) and higher equivalent ratios ($\Phi$ > $1.1{\sim}1.2$).

• Journal of the Korean Society of Safety
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• 제2권3호
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• pp.37-43
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• 1987

The combustion process in gas turbine combustor mainly influenced by flow pattern in combustor, and especially the flow pattern near the nozzle and the shape of recirculation zone affect strongly on the flame stabilization, temperature distribution and combustion efficiency in combustor. In this paper, the author has designed and manufactured transparent simplified model combustors on the basis of K. Suzuki's combustor design method to investigate the effects of swirl number and secondary air hold arrays in axial position on the flow characteristics by adopting the tuft method and 5 hole pitot tube.

• Journal of ILASS-Korea
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• 제3권2호
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• pp.42-50
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• 1998

The effect of swirl flows un the fuel spray characteristics were investigated for various swillers in a model combustor. The interaction between the flow field and fuel spray in the main combustion tone made by frontal devices including fuel injection nozzles and swirlers. which were characterized by flow velocities, fuel droplet sizes and their distributions which were measured by APV(Adaptive Phase/Doppler Velocimetry) under atmospheric condition at 320cc/min kerosine fuel flow and 0.04kg/sec air supply. A dual swirler with circumferential two-stage swirl vanes of $40^{\circ}\;and\;45^{\circ}$ vanes in different directions and two single-stage swillers of $40^{\circ}$ vanes with 12 and 16 vanes were tested. It was found that the dual swirler has the largest recirculating zone with highest reverse flow velocity. The strongest swirl flow was found at the boundary of recirculation zone. Small fuel droplets were observed in the main axial stream and inside the recirculation zone when swirling flow field were generated by the frontal devices. These findings could give the tips on the optimal design of frontal devices to realize low emissions in gas turbine combustion.

• Aerospace Engineering and Technology
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• 제4권2호
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• pp.135-141
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• 2005

The procedure of conceptual and detailed design of sub-scale combustor using bipropellant swirl or impinging injector with external or internal mixing for a liquid rocket engine are described in this paper. The sub-scale combustor uses liquid oxygen(LOx) and kerosene as propellants and has a injector head, an ablative material combustor wall and a water cooled nozzle. The injector head has LOx manifold, fuel manifold, fire face plate, one center swirl or impinging injector and 18 main swirl or impinging injectors.

• Journal of Mechanical Science and Technology
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• 제20권12호
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• pp.2284-2291
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• 2006

The present study investigates gas residence time and mixing characteristics for various swirl numbers generated by injection of secondary air into a lab-scale cylindrical combustor. Fine dust particles and butane gas were injected into the test chamber to study the gas residence time and mixing characteristics, respectively. The mixing characteristics were evaluated by standard deviation value of trace gas concentration at different measurement points. The measurement points were located 25 mm above the secondary air injection position. The trace gas concentration was detected by a gas analyzer. The gas residence time was estimated by measuring the temporal pressure difference across a filter media where the particles were captured. The swirl number of 20 for secondary air injection angle of 5$^{\circ}$ gave the best condition: long gas residence time and good mixing performance. Numerical calculations were also carried out to study the physical meanings of the experimental results, which showed good agreement with numerical results.

• Transactions of the Korean Society of Mechanical Engineers B
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• 제27권1호
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• pp.95-104
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• 2003

The objective of this work is to investigate the turbulent reacting flow in a three dimensional combustor with emphasis on thermal NO emission through a numerical simulation. Flow field is analyzed using the SIMPLE method which is known as stable as well as accurate in the combustion modeling, and the finite volume method is adopted in solving the radiative transfer equation. In this work, the thermal characteristics and NO emission in a three dimensional combustor by changing parameters such as equivalence ratio and inlet swirl angle have investigated. As the equivalence ratio increases, which means that more fuel is supplied due to a larger inlet fuel velocity, the flame temperature increases and the location of maximum temperature and thermal NO has moved towards downstream. In the mean while, the existence of inlet swirl velocity makes the fuel and combustion air more completely mixed and burnt in short distance. Therefore, the locations of the maximum reaction rate, temperature and thermal NO were shifted to forward direction compared with the case of no swirl.