• Title/Summary/Keyword: 천음속 연소

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A Study of Transonic Premixed Combustion in a Diverging Channel Using Asymptotic Analysis (점근해석을 이용한 확대형 채널 내의 천음속 예혼합 연소에 관한 연구)

  • Lee, Jang-Chang
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.33 no.8
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    • pp.75-83
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    • 2005
  • A steady transonic dilute premixed combustion in a diverging channel is investigated by using asymptotic analysis. This model explores the nonlinear interactions between the near-sonic speed of the flow, the small changes in geometry from a straight channel, and the small heat release due to the one-step first-order Arrhenius chemical reaction. The reactive flow is described by a nonhomogeneous transonic small-disturbance (TSD) equation coupled with an ordinary differential equation for the calculation of the reactant mass fraction in the combustible gas. Also the asymptotic analysis reveals the similarity parameters that govern the reacting flow problem. The results show the complicated nonlinear interaction between the convection, reaction, and geometry effects and its effect on the flow behavior.

A Numerical Study of Channel Shape and Mach Number Effects on Transonic Combustion (채널형상과 마하수가 천음속 연소에 미치는 영향에 대한 수치해석적 연구)

  • Lee, Jang-Chang
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.33 no.11
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    • pp.65-73
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    • 2005
  • The compressible flow of reactive fluid is investigated by using the transonic small-disturbance (TSD) model and the one-step first-order Arrhenuis chemical reaction. The fluid flow is restricted to dilute premixed reactions with small heat release. The effects of channel shape and Mach number on transonic combustion are studied by numerical analysis. The results show that the channel divergence increases the chemical reaction within the given channel length whereas the channel convergence inhibits the chemical reaction near the outlet and that increasing the inlet flow Mach number at a fixed reaction rate causes the flow acceleration in a diverging channel and the appearance of weak shock waves which do not show in the inert flow case. It also helps to increase the pressure and temperature near the diverging channel outlet and to consume the reactant within the given channel length.

A Study of Transonic Combustion in a Diverging Channel Using Asymptotic Analysis (점근해석을 이용한 확대형 채널 내의 천음속 연소에 관한 연구)

  • Lee, Jang-Chang
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.1604-1610
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    • 2004
  • A steady dilute premixed combustion at transonic speeds in a diverging channel is investigated. The model explores the nonlinear interactions between the near-sonic speed of the flow, the small changes in geometry from a straight channel, and the small heat release due to the one-step first-order Arrhenius chemical reaction. The reactive flow can be described by a nonhomogeneous transonic small-disturbance (TSD) equation coupled with an ordinary differencial equation for the calculation of the reactant mass fraction in the combustible gas. The asymptotic analysis results in the similarity parameters that govern the reacting flow problem. The model is used to study transonic combustion at various amounts of incoming, reactant mass, reaction rates, and channel geometries.

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Effects of Underexpanded Plume in Transonic Region on Longitudinal Stability (천음속 영역에서 과소 팽창 화염이 종안정성에 미치는 영향에 관한 연구)

  • Jung, Suk-Young;Yoon, Sung-Joon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.32 no.8
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    • pp.118-128
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    • 2004
  • Exhaust plume effects on longitudinal aerodynamics of missile were investigated by wind tunnel tests using a solid plume simulator and CFD analyses with both the solid plume and air jet plumes. Approximate plume boundary prediction technique was used to produce the outer shape of the solid plumer and chamber conditions and nozzle shapes of the air jet plumes were determined through plume modeling technique to compensate the difference in thermodynamic properties between air and real plume. From comparisons among turbulence models in case of external flow interaction with the air jet plume, Spalart-Allmaras model turned out to give accurate result and to be less grid-dependent. Effects induced by the plume were evaluated through the computations with Spalart-Allmaras turbulence model and the air jet plume to account for various ratios of chamber and ambient pressure and Reynolds number under the flight test condition.

Prestudy on Expendable Turbine Engine for High-Speed Vehicle (초고속 비행체용 소모성 터빈엔진 사전연구)

  • Kim, You-Il;Hwang, Ki-Young
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2011.11a
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    • pp.629-634
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    • 2011
  • A prestudy on expendable turbine engine for high-speed vehicle was conducted. The two possible mission profiles were established to decide the engine requirements and Design Point, and Design Point analysis was performed with the values of design parameter which were obtained from similar class engines and technical references. The results showed that Specific Net Thrust is 2599.4 ft/s and Specific Fuel Consumption is 1.483 lb/($lb^*h$) at the flight condition of Sea Level, Mach 1.2. It was also found through the performance analysis on the two possible mission profiles that major design parameters for determining Net Thrust were Turbine Inlet Temperature for low supersonic flight speed and Compressor Exit Temperature for high supersonic flight speed. In addition, simple turbojet engine with axial compressor, straight annular combustor, axial turbine and fixed throat area converge-diverge exhaust nozzle was proposed as the configuration of simple low cost light engine.

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Prestudy on Expendable Turbine Engine for High-Speed Vehicle (초고속 비행체용 소모성 터빈엔진 사전연구)

  • Kim, YouIl;Hwang, KiYoung
    • Journal of the Korean Society of Propulsion Engineers
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    • v.17 no.1
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    • pp.97-102
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    • 2013
  • A prestudy on expendable turbine engine for high-speed vehicle was conducted. After two possible mission profiles were established to decide the engine requirements, design point analysis was performed with the values of design parameter which were obtained from similar class engines, references, etc. The results showed that specific net thrust and specific fuel consumption with turbine inlet temperature of 3,600 R are 2,599.4 ft/s and 1.483 lb/(lb*h) respectively at the flight condition of sea level, Mach 1.2. It was also found that major design parameters for determining maximum net thrust were turbine inlet temperature for low supersonic and transonic flight speed and compressor exit temperature for high supersonic flight speed from the results of performance analysis on the two possible mission profiles. In addition, simple turbojet engine with an axial compressor, a straight annular combustor, an one stage axial turbine and a fixed throat area converge-diverge exhaust nozzle was proposed as the configuration of simple low cost lightweight turbine engine.