• 항공우주시스템공학회지
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• 제1권4호
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• pp.7-12
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• 2007

From the beginning of aviation history, in-flight smoke/fire events have been a serious issue. As aircraft are getting larger and are becoming more auto-piloted and aircraft systems are getting more complex, it is an increasing risk of in-flight smoke/fire accidents accompanied with fire events. Therefore, we review the statistics of fire/smoke accidents in order to enhance an understanding for risk of in-flight smoke events, and present the certification requirements for smoke per KAS Part 25. In addition, we provide acceptable methods of complying with related requirements, such as smoke detection test, smoke penetration test and smoke evacuation test.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.384-388
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• 2007

Aerodynamic characteristics of Coleoptera species of Epilachna quadricollis and Allomyrina dichotoma are experimentally and numerically investigated. Using digital high speed camera and smoke wire technique, we visualized the continuous wing kinematics and the flight motion of free-flying coleoptera. The experimental visualization shows that the elytra flapped concurrently with the main wing both in the downstroke and upstroke motions. The wing motion of Epilachna quadricollis was captured and analyzed frame by frame to identify the kinematics of the wings and to implement it in the movement of a model wing (thin plate) in the simulation. The two-dimensional simulation of Epilachna quadricollis hovering flight was performed by assuming the wing cross section shape as a thin plate, even though most of insect's wings are made of curved corrugated membrane. The effect of Reynolds number are investigated by the simulation. Meanwhile, in order to investigate the role and effect of elytra, the flow visualization of Allomyrina dichotoma was carried on using smoke wire visualization technique. Here, we confirmed that the vortex generated by elytra due to its movement is strongly influence the vortex dynamic generated by hind wings.

• 대한조선학회논문집
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• 제59권4호
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• pp.225-234
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• 2022

The flow field measurement above whole area of the flight deck on 'Landing Platform Helicopter (LPH)' was performed by using PIV system in wind tunnel. In various heading angle conditions (0deg, -30deg, -45deg, -60deg, -75deg and ±90deg), the velocity fields such as U velocity & V velocity were measured at three different height above flight deck. Due to the geometrical characteristics of several bodies like deck, crane and super-structure, various vortex were generated. When the heading angle is 0deg, the deck edge vortex by flight deck and massive separation by super-structure were clearly observed by visualization with smoke and PIV, respectively. In other heading angles, the acceleration of flow in space between crane and super-structure were detected. And area with flow separation by super-structure is directly related to the heading angle of vessel.

• 한국가시화정보학회지
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• 제2권2호
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• pp.58-65
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• 2004

The purpose of this visualization study is to investigate the effect of reduced frequency qualitatively by examining wake patterns for dragonfly flight motion. Dragonflies have two pairs of wing (a forewing and hindwing) and flight is achieved by a pitching and plunging, so it makes a separation over the wings. The separation affects the wake pattern and changed wake pattern has an influence on lift, drag, and propulsion. This experiment was conducted by using a smoke wire technique and a camera fixed above the test section used to take a photograph of the wake. An electronic device is mounted below the test section to find the exact mean positional angle of the wing. The reduced frequency in the experiment is 0.15, 0.3 and 0.45. Results show that reduced frequency is closely related to the wake pattern that determines flight efficiency.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1566-1569
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• 2008

The flow visualization is conducted in order to investigate an unsteady flight characteristic of a model dragonfly. The flapping wings are analyzed using smoke-wire and high speed camera. The results of this experiment show that three mechanisms and high incidence angle of the wings are responsible for the lift. The leading edge vortex, which is induced by the rapid acceleration of the wing at the beginning of a stroke, causes the lift enhancement. The delayed stall during the stroke and the fast supination and pronation of the wing near the end of each stroke are also responsible for the lift generation.

• 한국추진공학회지
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• 제17권5호
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• pp.10-17
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• 2013

로켓의 노즐 외부에서 형성되는 플룸으로 인하여 발사 위치나 비행궤적이 노출 될 수 있는데, 본 논문에서는 플룸을 감소시킬 수 있는 고체 추진제의 후연소 반응 억제제에 대하여 연구 결과를 제시하였다. 후연소 방지제가 무연계 고체추진제의 내탄도 성능과 일차 연기에 미치는 영향을 분석하였으며, 후연소 반응 방지제로 $K_2SO_4$를 1.1% 적용하여 후연소 반응이 크게 감소하는 것을 알 수 있었다. 또한 $K_2SO_4$의 함량이 증가하면 압력지수가 미세하게 증가하며, 1차 연기의 발생량도 증가하므로 1.1% 이하를 사용해야 AGARD 기준으로 1차 연기 A등급에 부합되는 것으로 분석되었다.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2008년도 정기총회 및 학술발표대회
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• pp.625-628
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• 2008

The behavioral response of the individuals intimately involved with the initiation of the fire or those who aware of the initial fire cue, often appeared to be a determinant to the outcome of the fire incident, the nonadaptive flight or panic type behavioral response appears to be an infrequent, unusual or unique participant behavioral response in most fire incidents. Therefore, this study focused on the investigation of the individual behavioral responses depend on the distinction of sex and age.

• 한국항공우주학회지
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• 제32권9호
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• pp.130-135
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• 2004

본 논문은 국내 최초로 그레인의 형상을 조절하여 설계한 이중추력형 로켓 모터의 개발에 관하여 기술하였다. 저연소속도 저연 추친제의 조성 및 finocyl형 그레인을 이용한 로켓 모터의 설계와 연소시험 데이터의 분석/평가 결과를 상술하였다. 개발된 이중추력형 로켓 모터는 비행시험에 성공적으로 적용되어 유도탄의 성능향상에 크게 기여하였고, 개발 결과는 향후 유사한 로켓 모터의 개발에 유용하게 사용될 것이다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.1586-1591
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• 2004

Flow visualization experiments have been performed to investigate the effects of phase lag, reduced frequency qualitatively by examining wake pattern on a dragonfly type wing. The model was built with a scaled-up, flapping wings, composed of paired wings with fore- and hindwing in tandem, that mimicked the wing form of a dragonfly. The present study was conducted by using the smoke-wire technique, and an electronic device was mounted to find the exact positional angle of wing below the tandem wings, which amplitude is ranged from $-16.5^{\circ}$ to $+22.8^{\circ}$. Phase lag applied on the wings is $0^{\circ}$, $90^{\circ}$, $180^{\circ}$ and $270^{\circ}$. The reduced frequency is 0.15, 0.3 and 0.45 to investigate the effect of reduced frequency. It is inferred through observed wake pattern that the phase lag clearly plays an important role in the wake structures and in the flight efficiency as changing the interaction of wings. The reduced frequency also is closely related to wake pattern and determines flight efficiency.

• International Journal of Contents
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• 제2권2호
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• pp.1-5
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• 2006

The modeling and animation of natural phenomena have received much attention from the computer graphics community. Synthetic of natural phenomena are required for such diverse applications as flight simulators, special effects, video games and other virtual realty. In special effects industry there is a high demand to convincingly mimic the appearance and behavior of natural phenomena such as smoke, waterfall, rain, and fire. Particle systems are methods adequate for modeling fuzzy objects of natural phenomena. This paper presents particle system API(Application Program Interfaces) for generating special effects in virtual reality applications. The API are a set of functions that allow C++ programs to simulate the dynamics of particles for special effects in interactive and non-interactive graphics applications, not for scientific simulation.