자동차 보강재 경량화을 위한 충격 실험장치 개발

김익태(Kim, Ick-Tae),강형선(Kang, Hyung-Seon) 한국산학기술학회 2014 한국산학기술학회논문지 Vol.15 No.10

본 자동차 충돌사고는 인간이 자동차 문명을 발전시킨 이래 누려온 편의성의 대가이기 때문에 많은 사람들이 충돌 사고 시 승객의 사망과 상해를 기술적으로 감소시키기 위해 여러 가지 노력을 기울여 왔다. 도로교통공단 통계자료에 따르면 승용차 충돌사고로 인한 사망자 충 측면충돌사고에 의한 사망자가 정면충돌사고의 사망자보다 많다. 자동차 설계자들은 이 에 대응하기 위해 도어 내부에 임팩트 빔(Impact Beam)과 임팩트 프레임(Impact Frame)이라는 보강재를 추가시켜 왔다. 이러한 보강재 개발을 위해 충돌실험은 필수적이다. 충돌실험의 경우 많은 비용과 시간이 소모되게 된다. 본 연구는 임팩터를 떨어뜨려 충격량과 변형량을 얻을 수 있는 실험장치 개발이 목적이다. 경제적 비용을 줄일 수 있는 이상적인 실험장치 구성 을 제시하고, 수치해석 값과 실험결과 값을 비교 분석한 결과 충돌 시작 후 3.5E-3sec에서 각각 3.49E-3, 3.99E-3의 변형량을 나타냈다. Reducing the impact of collisions of cars is a major issue for reducing the injury and death of passengers. According to the statistical data of the Road Traffic Authority, the deaths from side collision accidents caused by the collision of passenger cars is greater than the deaths from head-on collision accidents. To accommodate this, vehicle designers have added a reinforcing material called the impact frame and impact beam on the inside of the door. Many experiments are needed to develop the door impact beam. These reinforcements to develop a collision experiment is essential. Collision experiments are costly and time consuming. This study used a drop Impactor to obtain the impulse and a strain experimental device was developed for this purpose. The economic costs were reduced and the ideal experiment device configuration was determined. A comparison of the experimental results with numerical value analysis revealed 3.5 × 10-3sec strain ranging from 3.49 × 10-3 to 3.99 × 10-3

축소 헬기 지상시험을 위한 헬리콥터 섀시다이나모미터 개발

김익태(Ick-Tae Kim),김재수(Jae-Soo Kim) 한국항공우주연구원 2012 항공우주기술 Vol.11 No.1

본 논문에서는 축소 로터의 성능시험과 축소 헬기 Flight Test Bed 개발이 가능한 헬리콥터 섀시다이나모미터(HCDS)를 개발하여 지상시험을 수행하였다. 축소 헬기는 엔진 출력에 따른 컬렉티브 피치각의 상호 관계로부터 로터의 일정 회전속도에 대한 추력과 동력의 변화를 확인하고, 그 결과로 OGE에서의 정지비행효율(F.M.)이 0.76으로 비행시험 가능성을 점검하였다. 본 헬리콥터 섀시다이나모미터(HCDS) 시험 결과는 축소 헬기 개발과 로터 블레이드의 성능 평가에 활용할 것이다. This paper developed Helicopter Chassis Dynamometer System(HCDS) to perform the bench test of the scaled rotor blade and to design a scaled model helicopter flight test bed and accomplished the scaled helicopter ground test. The scaled helicopter should be checked the relation of thrust and power input to maintain regular RPM by collective pitch angle versus throttle input. It showed hovering performance results of IGE with OGE, the max. F.M. was 0.76 without ground effect. The results of the chassis dynamometer test of scaled helicopter will usefully apply to design the scaled helicopter and evaluate the rotor blade performance.

슬롯 분사가 있는 후향계단 유동장 분석을 위한 초음속풍동 설계

김익태(Ick-Tae Kim) 한국산학기술학회 2016 한국산학기술학회논문지 Vol.17 No.11

본 연구는 마하수 2.5의 초음속 영역에서 마하수 1.0의 슬롯 분사가 있는 후향계단 형상에 대한 유동장 특성을 분석하기 위하여 초음속풍동 시험부를 설계, 제작하였다. 비행체가 고속으로 움직일 때 공동 주위의 유동은 매우 복잡하여 수치해석 결과를 검증할 초음속풍동 시험 자료가 필요하기 때문에 기존의 2차원 대칭형 노즐을 아랫면이 평판인 비대칭형 노즐로 수정하였다. 특성곡선해법을 이용한 비점성 노즐을 설계하고, 시험을 통해 얻은 경계층 두께를 노즐에 반영하여 보정한 기법을 C 언어로 프로그래밍하여 얻은 결과를 수치해석 결과와 비교하여 검증하였다. 슬롯 분사 시 지속적인 유동장 변화 분석을 위한 초음속 유지시간 확보를 위해 저장탱크의 압력 변화에 따른 PID 제어프로그램 수정으로 초음속 유동 유지시간을 약 5초에서 약 6초로 1초 정도 연장하여 제어 효율을 향상하였고, 슬롯 분사가 있는 후향계단에서의 유동장 변화를 슐리렌장치로 가시화하여 복잡한 유동장 특성을 확인하였다. 향후 슬롯 분사의 속도와 유량, 유동장의 온도를 변화하여 공동에서의 막냉각 효과 분석을 위한 장비로 사용할 계획이다. A test section of a supersonic wind tunnel was designed for the analysis of flow characteristics over a backward-facing step with Mach 1.0 slot injection in a supersonic flow of Mach 2.5. The cavity flow of a high-speed vehicle is very complex at supersonic speed, so it is necessary to do experiments using supersonic wind tunnels to verify numerical analysis methods. The previous 2D symmetrical nozzle was replaced with an asymmetrical nozzle. The inviscid nozzle contour was designed using Method of Characteristics (MOC), and the boundary layer thickness correction was reflected by experimental data from the wind tunnel. The results were compared with a CFD analysis. The PID control system was changed to be based on the change of tank pressure. This improved the control efficiency, and the run times of supersonic flow increased by about 1 second. The flow characteristics over a backward facing step with slot injection were visualized by a Schlieren device. This equipment will be used for an experimental study of the film cooling effectiveness over a cavity with various velocities, mass flows, and temperatures.

Al 평판의 표면 온도에 따른 열화상 카메라의 성능 분석

김익태(Ick-Tae Kim),오평안(Pyeong-An Oh),양승호(Seung-Ho Yang),김송주(Song-Ju Kim) 한국정보기술학회 2023 Proceedings of KIIT Conference Vol.2023 No.6

성형작약 제트를 이용한 Ammonium DiNitramide (ADN) 단일추진제 추력기 성능 분석

엄태호 ( Tae Ho Eom ),김익태 ( Ick Tae Kim ),이창열 ( Chang Yull Lee ) 조선대학교 공학기술연구원 2020 공학기술논문지 Vol.13 No.3

A performance analysis using CFD (Computational Fluid Dynamics) simulation was carried out for the solid propellant engine based on shaped charge jet. The purpose of this study is to find the optimal thrust efficiency geometry according to the change of propellants and nozzle shapes. In order to improve the thrust efficiency in relation to weight, the shape and weight of the engine were modified with the shaped charge principle. The thrusters of various shapes were modeled, and thrust performance was analyzed through CFD simulations. The results show that the shape of the propellants and nozzles using the shaped charge jet was the efficient thruster modeling relative to weight.

기능성 소화불량증에 사용된 침구치료방법에 대한 체계적 문헌고찰

김보영 ( Bo-young Kim ),서복남 ( Bok-nam Seo ),박지은 ( Ji-eun Park ),양창섭 ( Chang-sop Yang ),김익태 ( Ick-tae Kim ),임지원 ( Ji-won Im ),김영은 ( Young-eun Kim ) 대한경락경혈학회 2017 Korean Journal of Acupuncture Vol.34 No.1

The aim of this study is to review the methodology of clinical trials conducted with the acupuncture and moxibustion treatment on functional dyspepsia. Methods : We searched four international databases and three Korean databases including English, Korean and Chinese, through March 2016 for randomized controlled trials(RCT) and non-randomized case-control trials(CCT) that evaluated the effects of the acupuncture and moxibustion on functional dyspepsia. We abstracted the designs of the trials and the method of acupuncture and moxibustion treatment according to the Standards for Reporting Interventions in Clinical Trials of Acupuncture. Results : A total 117 papers were reviewed. The 106 studies were conducted in China. There were 111 RCTs(95%), and 6 CCTs(5%). Sixty eight studies(59%) were conducted with the manual acupuncture, 29 studies of electro- acupuncture(25%), 11 studies of moxibustion(9%), 5 studies of acupoints embedding therapy(4%), 4 studies of acupoint injection therapy(3%) were conducted. ST36, CV12, ST25 were most frequently used for acupoints to treat functional dyspepsia. In 59 studies(50%), western medication was used in the control group, and the effects of acupuncture and moxibustion were evaluated with the symptoms in most studies. Conclusions : These results suggest that it is necessary to develop more detailed reporting standards about acupuncture and moxibustion treatment method as the method of acupuncture and moxibustion is getting more diverse, and more objective tools are needed in evaluating functional dyspepsia.

수치해석을 이용한 수평축 소형 다운윈드 풍력터빈의 출력에 관한 연구

김성환(Seong-Hwan Kim),김익태(Ick-Tae Kim) 한국정보기술학회 2020 한국정보기술학회논문지 Vol.18 No.5

This study is a preliminary process for commercialization of a 300W class horizontal axis small downwind wind turbine. Numerical analysis is used to predict the power generation performance of a turbine according to the flow conditions for a 3D shape. A basic design using a 3D CAD was performed, and aerodynamic performance by computational fluid analysis was calculated based on the design data to verify the mechanical output that could occur in a wind turbine. Wind speeds were calculated every 1㎧ from 6㎧ to 12㎧ for analysis of wind turbine performance. The torque results were calculated by changing the RPM according to each wind speed condition. The mechanical power was calculated with torque and rotational speed. The results of this study will be used to ensure the stability of the wind turbine development process.