• Title/Summary/Keyword: Jet Shear Layer

Search Result 73, Processing Time 0.017 seconds

Characteristic Study on Effect of the Vent Mixer to Supersonic Fuel-Air Mixing with Stereoscopic-PIV Method (3차원 PIV 기법을 사용한 벤트혼합기가 초음속 연료-공기 혼합에 미치는 특성 연구)

  • Kim, Chae-Hyoung;Jeung, In-Seuck;Choi, Byung-Il;Kouchi, Toshinori;Masuya, Goro
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2012.05a
    • /
    • pp.378-385
    • /
    • 2012
  • Vent mixer can provide main flow directly into a recirculation region downstream of the mixer to enhance fuel-air mixing efficiency. Based on experimental results of three-dimensional velocity, vorticity and turbulent kinetic energy obtained by a stereoscopic PIV method, the performance of the vent mixer was compared with that of the step mixer which was used as a basic model. Thick shear layers of the vent mixer induced the increase of the penetration height. The turbulent kinetic energy mainly distributed along a boundary layer between the main flow and the jet plume. This turbulent field activates mass transfer in a mixing region, leading to the mixing enhancement.

  • PDF

Characteristic Study on Effect of the Vent Mixer to Supersonic Fuel-Air Mixing with Stereoscopic-PIV Method (3차원 PIV 기법을 사용한 벤트혼합기가 초음속 연료-공기 혼합에 미치는 특성 연구)

  • Kim, Chae-Hyoung;Jeung, In-Seuck;Choi, Byung-Il;Kouchi, Toshinori;Masuya, Goro
    • Journal of the Korean Society of Propulsion Engineers
    • /
    • v.16 no.4
    • /
    • pp.50-56
    • /
    • 2012
  • Vent mixer can provide main flow directly into a recirculation region downstream of the mixer to enhance fuel-air mixing efficiency. Based on experimental results of three-dimensional velocity, vorticity and turbulent kinetic energy obtained by a stereoscopic PIV method, the performance of the vent mixer was compared with that of the step mixer which was used as a basic model. Thick shear layers of the vent mixer induced the increase of the penetration height. The turbulent kinetic energy mainly distributed along a boundary layer between the main flow and the jet plume. This turbulent field activates mass transfer in a mixing region, leading to the mixing enhancement.

Ground Test & Evaluation of Conformal Load-bearing Antenna Structure for Communication and Navigation (통신 항법용 다중대역 안테나 내장 스킨구조의 지상시험평가)

  • Kim, Min-Sung;Park, Chan-Yik;Cho, Chang-Min;Jun, Seung-Moon
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.41 no.11
    • /
    • pp.891-899
    • /
    • 2013
  • This paper suggests a test and evaluation procedure of conformal load-bearing antenna structure(CLAS) for high speed military jet application. A log periodic patch type antenna was designed for multi-band communication and navigation antenna. Carbon/Glass fiber reinforced polymer was used as a structure supporting aerodynamic loads and honeycomb layer was used to improve antenna performance. Multi-layers were stacked and cured in a hot temperature oven. Gain, VSWR and polarization pattern of CLAS were measured using anechoic chamber within 0.15~2.0 GHz frequency range. Tension, shear, fatigue and impact load test were performed to evaluate structural strength of CLAS. Antenna performance test after every structural strength test was conducted to check the effect of structural test to antenna performance. After the application of new test and evaluation procedure to validate a new CLAS, a design improvement was found.