• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년 영문 학술대회
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• pp.671-679
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• 2008

The effect of Pre-cooled Turbojet Engine installation and nozzle exhaust jet on Hypersonic Turbojet EXperimental aircraft(HYTEX aircraft) were investigated by three-dimensional numerical analyses to obtain aerodynamic characteristics of the aircraft during its in-flight condition. First, simulations of wind tunnel experiment using small scale model of the aircraft with and without the rectangular duct reproducing engine was performed at M=5.1 condition in order to validate the calculation code. Here, good agreements with experimental data were obtained regarding centerline wall pressures on the aircraft and aerodynamic coefficients of forces and moments acting on the aircraft. Next, full scale integrated analysis of the aircraft and the engine were conducted for flight Mach numbers of M=5.0, 4.0, 3.5, 3.0, and 2.0. Increasing the angle of attack $\alpha$ of the aircraft in M=5.0 flight increased the mass flow rate of the air captured at the intake due to pre-compression effect of the nose shockwave, also increasing the thrust obtained at the engine plug nozzle. Sufficient thrust for acceleration were obtained at $\alpha=3$ and 5 degrees. Increase of flight Mach number at $\alpha=0$ degrees resulted in decrease of mass flow rate captured at the engine intake, and thus decrease in thrust at the nozzle. The thrust was sufficient for acceleration at M=3.5 and lower cases. Lift force on the aircraft was increased by the integration of engine on the aircraft for all varying angles of attack or flight Mach numbers. However, the slope of lift increase when increasing flight Mach number showed decrease as flight Mach number reach to M=5.0, due to the separation shockwave at the upper surface of the aircraft. Pitch moment of the aircraft was not affected by the installation of the engines for all angles of attack at M=5.0 condition. In low Mach number cases at $\alpha=0$ degrees, installation of the engines increased the pitch moment compared to no engine configuration. Installation of the engines increased the frictional drag on the aircraft, and its percentage to the total drag ranged between 30-50% for varying angle of attack in M=5.0 flight.

• 디지털융복합연구
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• 제19권4호
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• pp.251-257
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• 2021

뉴 미디어의 발전으로 인해 사람들의 정보 습득 방식에 커다란 변화가 생기고 있다. 글이나 사진보다 콘텐츠 내용을 더 입체적인 전달할 수 있는 영상콘텐츠 활용이 그 변화다. 2016년 이후 실시간 라이브 방송 콘텐츠는 제공자와 사용자 모두 증가하는 추세이다. 본 논문은 Youtube Live 또는 DouyuTV를 플렛폼으로 하는 개인의 실시간 라이브 방송 콘텐츠를 연구 대상으로 하였다. 개인의 실시간 라이브 방송 사례에 수록된 디지털화된 정보 내용의 특징 또는 필요성을 분석하였다. 2020년에 코로나19로 인한 온라인 생활의 변화는 실시간 라이브 방송을 더 다양한 분야로 확대될 수 있음을 보여주었다. 디지털 첨단기술을 용합한 실시간 라이브 방송은 내용적인 측면 뿐만 아니라 영상콘텐츠를 소비하는 대중들의 영상 소비 문화에도 다양성을 제공하여 더 많은 사회적 가치를 만들 것으로 예측된다. 그러므로 향후 실시간 라이브 방송콘텐츠의 사회적 책임에 관한 심도 있는 연구가 필요하다고 생각한다.