• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.12
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• pp.848-855
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• 2019

Eco-friendly gas turbine combustors are getting attention due to emission regulations. Swirler is important design factor for flame stability and flashback inside the combustor. Design methods of the axial swirler and the radial swirler were discussed and the suitability of the swirl number calculation considering the geometric design variables and the flow loss was examined in the radial swirl for gas turbine combustor. The swirl number of flow was calculated by computational fluid dynamics and compared with swirl number according to each design method.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.05a
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• pp.77-81
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• 2008

The local regression rate behavior of solid fuel in swirl injection hybrid rocket were studied. In generally, axial injection regression rate was tending to be decrease with axial distance, beyond which increased with increasing axial distance from the leading edge. On the other hand, swirl injection regression rate was high at the leading edge of the fuel and comparatively uniform regression rate at the downstream. Overall regression rate of swirl injection was increased about 54% for the overall regression rate of axial injection. Through this study, it was found that using swirl injector was useful in applying to the small sounding rocket.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.445-450
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• 2011

Swirling flows inside a swirl mixing chamber are investigated for simple configuration where swirl is produced by a tangential entry type swirl generator. The flow downstream of the swirl generator has been quantified by measurements two velocity components and their corresponding mean values along axial and radial direction using Particle Image Velocimetry(PIV). The mass flow rate of the tangential entry is increased in order to study their effect on the flow field. From the measurement profile of velocity and vorticity, flow mixing characteristics in a swirl mixing chamber are evaluated.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.4
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• pp.70-76
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• 2002

Characteristics of kerosine spray combustion were investigated at various swirl condition. PDPA(Phase Doppler Particle Analysis) was used to measure the droplet sizes and velocities. R-type(Platinum vs. Platinum-13%rhodium) thermocouple was used to measure the temperature of combustion flow field inside model combustor. A visualization of spray and flame was performed with still camera. As swirl number increases due to increase of swirl vane angle, the spray and the flame were developed to radial direction rapidly. When swirl number is small, the configuration of flame is cone type, but swirl number is large, the configuration of flame is cylindrical type due to enhanced mixing by the transport of swirl momentum.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.1 no.4
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• pp.265-275
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• 1989

An experimental study of decaying swirl air flow has been obtained by tangential inlet in a straight tube with Reynolds number range 20,000~40,000. The friction factor, swirl angle, velocity profiles and turbulent intensity are measured by using micro-manometer and hot-wire anemometer. It is found that the swirl flow behaviors depend on the swirl intensity along the test tube.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.74-77
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• 2011

A mixing characteristics on recess length change of Gas-centered swirl coaxial injector using high-performance staged combustion rocket engine carry out study through CFD(Computational fluid dynamics). propellant phase that combined gas-liquid simulate gas-gas. In order to measure spreading angle, velocity distribution to injector exit and spray structure of propellant analyzed. Axial velocity increase by increasing recess length, but tangential velocity decrease. The result confirmed qualitative characteristics that the spreading angle decreases.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.05a
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• pp.67-70
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• 2008

Production and dissipation of turbulent structure in a swirl stabilized combustor was investigated using three-dimensional Large Eddy Simulation analysis. The combustor of concern is the LM6000, lean premixed dry low-NOx annular combustor, developed by GEAE. Inlet condition was based on experimental data. Strong vortex breakdown in main stream, vortex ring proceeding downstream, and the turbulent structure periodically oscillating have been observed. Reasonable agreement was obtained by comparison of the results with experiments and previous LES studies.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.7
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• pp.97-104
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• 2006

The spray and breakup characteristics of swirling liquid sheet were investigated by measuring the spray angle and breakup length as the axial Weber number Wel was increased up to 1554 and the ambient gas pressure up to 4.0MPa. As Wel and ambient gas density increased, the disturbances on the annular liquid sheet surface were amplified by the increase of the aerodynamic forces, and thus the liquid sheet disintegrated near from the injector exit. The measured spray angles according to the ambient gas density were different before and after the sheet breaks. Before the liquid sheet breaks, the spray angle was almost constant, but once the liquid sheet started to breakup, the spray angle decreased. And the breakup length decreased because of the increase of the aerodynamic force as the ambient gas density and Wel increased. Lastly, the measured breakup length according to the ambient gas density and Wel was compared with the result by the linear instability theory. We found that the corrected linear instability theory considering the attenuation of sheet thickness agrees well with our experimental results.

• Journal of Power System Engineering
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• v.6 no.4
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• pp.23-29
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• 2002

This paper is studied to investigate the effect of slits and swirl vanes on the main flow fields of a gun-type gas burner through X-Y plane and Y-Z plane respectively by using X-probe from hot-wire anemometer system. This experiment was carried out with flow rate $450{\ell}/min$ in respective burner models installed in the test section of a subsonic wind tunnel. The burner models with only slits and only swirl vanes respectively were made by modifying original gun-type gas burner. The fast jet flow spurted from slits played a role such as an air-curtain because it encircled rotational flow by swirl vanes and drives mixed main flow to axial direction. As a result, the gun-type gas burner had a wider flow range up to about Y/R=1.5 deviated from slits and maintains a comparatively large velocity in the central part of burner within the range of about X/R=2.5. Therefore, it was very desirable that swirl vanes were installed within slits in gun-type gas burner in order to control the main flow fields effectively.

• Journal of Power System Engineering
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• v.5 no.2
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• pp.22-29
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• 2001

This paper represents axial mean velocity, turbulent kinetic energy and swirl number based on momentum flux measured in the X-Y plane and Y-Z plane respectively of a cone type gas swirl burner by using X-probe from the hot-wire anemometer system. This experiment is carried out at flow rates 350 and $450{\ell}/min$ respectively, which are equivalent to the combustion air flow rate necessary for heat release 15,000 kcal/hr in gas furnace, in the test section of a subsonic wind tunnel. Axial mean velocities and turbulent kinetic energies show that their maximum values exist centering around narrow slits situated radially on the edge of and in the forefront of a burner until $X/R{\fallingdotseq}1.5$, but they have a peculiar shape like a starfish diffusing and developing into inward and outward of a burner by means of the mixing between flows ejected from narrow slits, an inclination baffle plate and swirl vanes respectively according to downstream regions. Moreover, they show a relatively large value in the inner region of 0.5$S_m$ obtained by integration of velocity profiles shows a characteristic that has an inflection point composing of the maximum and minimum value until X/R<3, but shows close agreement with the geometric swirl number after a distance of X/R=3.