• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2011년 춘계학술대회논문집
• /
• pp.465-468
• /
• 2011

Ice accretion on aircraft surface can greatly deteriorate the safety of aircraft. In particular, it can be a cause of impediment for aircraft performances such as aerodynamic characteristics, control, and engine. Numerical simulation of icing accretion based on the state-of-art CFD techniques can be alternative to expensive icing wind tunnel test or flight test. In this study, icing conditions are defined in order to predict the ice accretions around the air intake of aircraft. Then the range and amount of ice accretion on the intake in icing wind tunnel were investigated In addition, a study on the size effect of icing wind tunnel was conducted in order to check the compatibility with the real in-flight test environment.

• 한국항공운항학회지
• /
• 제19권4호
• /
• pp.1-5
• /
• 2011

The free-wing tilt-body aircraft is researched in the flight performance characteristics for center of gravity (CG) change. All of speed, body tilt angle and center of gravity change are simulated to determine the flight envelope by a non-linear 3-DOF mathematical model. In flight, this aircraft configuration changes by the tiltable empennage. Then, flight dynamics distinguishes from those of a conventional fixed-wing aircraft. Though flight performance and trimmability are studied by CG change, the flight model of free-wing tilt-body aircraft is to reduce the hidden risk and to achieve the successful flight test. It is analyzed the flight characteristics by CG change that distinguishes free-wing tilt-body aircraft from the conventional aircraft.

• Advances in aircraft and spacecraft science
• /
• 제1권1호
• /
• pp.43-67
• /
• 2014

This paper presents a new conceptual design model ACAD (Adaptable Conceptual Aircraft Design), which differs from the other models due to its considerable adaptability to the different classes of aircraft. Another significant feature is the simplicity of the process which leads to the preliminary design outputs and also allowing a substantial autonomy in design choices. The model performs the aircraft design in terms of total weight, weight of aircraft subsystems, airplane and engine performances, and basic aircraft configuration layout. Optimization processes were implemented to calculate the wing aspect ratio and to perform the design requirements fulfillment. In order to evaluate the model outcomes, different test cases are presented: a STOL ultralight airplane, a new commuter with open-rotor engines and a last generation fighter.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2007년도 춘계 학술대회논문집
• /
• pp.14-16
• /
• 2007

A critical problem in the integration of stores into new and existing aircraft is the safe separation of the stores from the aircraft at a variety of flight conditions representative of the aircraft flight regime. Typically, the certification of a particular store/aircraft/flight condition combination is accomplished by a flight test. Flight tests are very expensive and do expose the pilot and aircraft to a certain amount of risk. Wind tunnel testing, although less expensive than flight testing, is still expensive. Computational Fluid Dynamics(CFD) has held out the promise of alleviating expensive and risk by simulating weapons separation computationally. The forces and moments on a store at carriage and at various points in the flow field of te aircraft can be computed using CFD applied to the full aircraft and store geometry. This study needs full dynamic characteristics study and flow analysis for securing store separation safety. Present study performs dynamic simulation of store separation with flow analysis using Chimera grid scheme which is usually used for moving simulations.

• 한국소음진동공학회논문집
• /
• 제16권5호
• /
• pp.503-513
• /
• 2006

The duration time of aircraft noise event is also an important factor for the evaluation of civil aircraft noise, which is considered as a notable characteristic of military aircraft noise. SEL is proved as a suitable noise metric for the measuring military aircraft noise of various flight pattern considering the duration time of noise event. This study reviews whether SEL is a suitable for measuring civil aircraft noise and study shows SEL is fairly compensating the duration time of civil aircraft noise event for the evaluation of aircraft noise. Noise metric for the evaluation aircraft noise based on SEL is more appropriate than based on $L_{MAX}$ for compensating duration time of noise event either military aircraft or civil aircraft. In this reason, current formula of WECPNL based on energy average of measured $L_{MAX}$ for the evaluation of aircraft noise impact in 'Test Method of Noise and Vibration of Korea' is recommended to be amended to formula of WECPNL based on energy average of measured SEL considering compensation of noise event duration time, if WECPNL is not based on measured EPNL, a metric compensating duration time.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• 제18권2호
• /
• pp.145-153
• /
• 2007

Objectives: This study was focused on the influence of chronic aircraft noise exposure on children's continuous performance, intelligence and reading skill. Methods: We enrolled 586 children in 4-6th grade of 7 primary schools near air base in Korea. Continuous performance was measured using the computerized ADS program. We analyzed 477-512 children on the visual continuous performance test, auditory continuous performance test, intelligence test, and reading and the vocabulary test. Intelligence was measured using vocabulary, digit span, block design, and digit symbol tests of K-WISC-III. Results: The commission error and variability deviation of auditory continuous performance test and reading test were significantly higher among children in schools with the helicopter noise and the fighting plane noise compared to children in the low noised schools. Conclusion: There was a possibility that chronic aircraft noise exposure was associated with impairment of the school performance. The result of our study also shows chronic aircraft noise was associated with reading ability.

• 대한기계학회논문집A
• /
• 제40권8호
• /
• pp.759-765
• /
• 2016

항공기 등에 사용되는 Flexible PTO(Power Take-Off) 샤프트는 스프링 특성을 좋게 하기 위해 여러장의 얇은 멤브레인을 용접한 형태로 1950년대에 이미 개발됐으며, AMAD(Aircraft Mounted Accessory Drive) 기어박스와 EMAD(Engine Mounted Accessary Drive) 기어박스 사이에서 회전동력을 전달한다. 이런 종류의 샤프트는 가볍고 특히 스프링 특성이 좋기 때문에 축 정렬이 틀어진 고속회전 상태에서도 안정적으로 회전동력을 전달할 수 있어 대부분의 전투기에 사용된다. 이번 연구에서 티타늄 합금으로 개발된 Flexible PTO 샤프트의 구조해석을 통해 제품의 안전성을 확인하였고, 실제 실험실에서 진행된 고속회전 시험에서 굽힘과 비틀림 부하를 동시에 인가하여 샤프트의 고주기 피로에 대한 내성을 실증하였다. 또한, 고주기 피로 시험 조건에서 항공기용 볼 조인트의 마모 특성 분석을 통해 수명을 예측하였다.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2002년도 ICCAS
• /
• pp.57.2-57
• /
• 2002

1. Introduction 2. Dynamics of Aircraft Landing 3. ABS Control Unit 4. Test 5. Conclusions

• 한국군사과학기술학회지
• /
• 제24권3호
• /
• pp.302-308
• /
• 2021

Developers generally use test standards suggested by military standards such as MIL-STD-810G when performing vibration tests in the materiel development. However, according to MIL-STD-810G, it is recommended to test by tailoring the test standard suitable for the developed materiel, and it is specified to apply the suggested test standard only when there is difficulty in tailoring. In addition, the test standards presented by MIL-STD-810G are standards created under operating conditions different from the actual operating environment of each developed materiel, so the test according to this standard may be excessive or understated. Therefore, the developer must create an appropriate vibration test standard for the developed materiel as similar to the operating conditions as possible. In this paper, the procedure for creating the functional test standard and durability test standard suitable for the operating environment of the equipment to be mounted on the propeller aircraft under development is described, and the created standard is introduced.

• 항공우주시스템공학회지
• /
• 제13권6호
• /
• pp.36-42
• /
• 2019

본 논문은 유/무인 항공기 복합운용체계 검증을 위한 시뮬레이션 환경 구축 및 통합 시험에 대하여 다룬다. 유/무인 항공기 지상 시뮬레이션 환경 구축을 위해서 유인기용 시뮬레이터인 X-Plane과 무인기용 시뮬레이터 HILS를 연동하여 상호 복합운영이 가능한지 시뮬레이션으로 검증하였다. 실제 비행시험 전 유/무인 항공기 및 지상통제실 간 C Band 및 UHF 채널을 이용한 통신 가능성을 확인하기 위하여 통신장비를 제작하고 유인 항공기를 이용한 검증을 수행하였다.