• Aerospace Engineering and Technology
• /
• v.13 no.2
• /
• pp.177-184
• /
• 2014

Flight safety analyses concerned with Launch Vehicle are performed to measure the risk to the people, ship and aircraft using impact point and impact dispersion area of debris generated by on-trajectory failures and malfunction turns. Predictions of impact point and impact dispersion area are essential for launch vehicle's flight safety analysis. Usually, impact dispersion area can be estimated in using Monte-Carlo simulation. However, Monte-Carlo method requires more several hundreds of iterative calculations which requires quite some time to produce impact dispersion area. Herein, we check the possibility of applying JU(Julier Uhlmann) transformation and Taguchi method instead of Monte-Carlo method and we propose a best method in terms of compuational time to produce impact dispersion area by comparing the results of the three methods.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.38 no.3
• /
• pp.280-287
• /
• 2010

The first Korean satellite launch vehicle, KSLV-I(Korea Space Launch Vehicle-I), was launched for its first flight test on Aug. 25, 2009 from Naro Space Center located in south Jolla province. Because launch vehicles usually fly long range with large amount of propellants aboard, preparation of countermeasures against potential malfunctions during flight is essential in launch operation. In this paper, the flight safety operation, prepared to guarantee flight safety during launch operation of KSLV-I, is presented. Prior to flight test, flight safety analysis is performed to estimate associated risk levels quantitatively, and during flight, flight safety systems are operated to cope with any risky situations. Real-time flight monitoring including computation of instantaneous impact point using tracking data is executed normally and the flight test is completed without activation of flight termination system.

• Journal of Advanced Navigation Technology
• /
• v.28 no.4
• /
• pp.408-419
• /
• 2024

Currently, the airport is expected to improve flight punctuality and operational efficiency after establishing A-CDM, which provides a foundation for mutual cooperation based on an information sharing system among stakeholders. An important element of the A-CDM is to share time information generated by each stakeholder from the arrival of an aircraft to ground operations and departure of the aircraft, thereby supporting timely arrival and departure of aircraft and improving the efficiency and punctuality of airport operations. In the UAM system, a vertiport that plays a role similar to an airport also needs to establish a system to share time information generated by each stakeholder for efficient operation of limited resources. In this regard, a method is needed to identify time information that needs to be shared by each stakeholder and apply technology to share it. In this paper, we propose an application method for system technology that classifies and mutually shares time information generated by stakeholders related to Vertiport operation according to data characteristics.

• Aerospace Engineering and Technology
• /
• v.2 no.2
• /
• pp.25-32
• /
• 2003

In the present paper, a computational study on the hydrodynamic behavior of the inducer are presented including the effect of the mass flow rate. The adopted inducer showed very low head rise with high volume flow rates, which may be caused by the small passage area near the trailing edge. The static pressure distributions at the shroud surface are compared with experimental results showing very good agreements. The overall performance of the inducer such as, efficiency, head rise is also compared with experiments. The computational results are generally in good agreements with experimental ones near the design point, but at the high flow rate, the two results shows discrepancy.

• Aerospace Engineering and Technology
• /
• v.2 no.2
• /
• pp.142-150
• /
• 2003

Turbulent flows and related heat transfer in a square heated duct is investigated by a turbulence model and a large eddy simulation. The cooling channel of calorimeter is modeled to the square duct. The nonlinear k-ε-fμ model of Park et al. [3] is slightly modified and their explicit heat flux model is employed. The Reynolds number is varied in the range 4000≤Reｂ≤20000. The heat transfer is closely linked to the secondary flows which driven by the turbulent motion. Its magnitude is 1~3% of the mean streamwise velocity. The relation of Nu~Re0.8Pr0.34 is validated by comparing with the predicted Nu of k-ε-fμ model. Finally, the coherent structures and thermal fluctuations are scrutinized.

• The Bulletin of The Korean Astronomical Society
• /
• v.40 no.2
• /
• pp.59.4-60
• /
• 2015

"과학관의 설립 운영 및 육성에 관한 법률"에 의거하여 정식으로 등록된 전국의 국 공 사립 과학관은 2012년을 기점으로 100개를 넘었고 현재는 170여개 기관이 이른다. 해당 법률에서 규정하는 과학관은 국민들의 과학기술에 대한 이해증진 및 어린이와 청소년들의 과학에 대한 탐구심 함양, 과학문화의 대중화 등 과학문화 확산의 한 축으로 활용이 되고 있다. 과학관은 등록 요건에 따라 '종합과학관'과 '전문과학관'으로 분류를 하며 특히 전문과학관의 경우 과학의 여러 분야 중 한가지의 주제를 선정하여 그 주제에 맞는 전시물과 프로그램들을 운영하고 있다. 특히 천문과 우주를 테마로 한 과학관은 2009년 세계 천문의해를 기점으로 건립이 가속화 되었고 그 비중은 전체 과학관 중에 상당 부분을 차지하고 있다. 하지만 이에 대한 정확한 통계와 분류가 미흡하고 해당 기관들 상호간에 제대로 된 협력체계가 미비한 현실이다. 이와 유사한 박물관, 미술관, 도서관의 경우 과학관과 마찬가지로 해당 학문에 대한 홍보와 대중화를 위해 관련 법률이 마련되어 있는데 이들의 경우 관련분야에 종사하는 전공자들에 대한 별도의 자격제도와 해당 기관에서의 지위를 부여받은 것과는 상당한 차이를 보이고 있어 이들 법률의 비교를 통하여 각 기관들의 설립목적과 운영취지, 자격제도 등을 알아보고 천문우주 과학전공자들에 대한 객관적인 검증제도 도입 및 과학관 건립시 그들을 채용할 수 있는 객관적인 근거를 마련해 보고자 한다.

• Journal of Aerospace System Engineering
• /
• v.14 no.1
• /
• pp.8-15
• /
• 2020

In this paper, we propose a container wall and its boundary layer insulation design method that can maintain the temperature inside the spacecraft shipping container constantly under the condition that the heat or the external temperature changes severely to safely transport the satellite to the launch site. We will examine if the temperature inside the satellite shipping container is kept constant through the heat flow analysis and the satellite heat transfer analysis for the external environment of the satellite shipping container. Through the flow analysis inside the container, the flow distribution around the satellite in the container is analyzed, and the auxiliary fan, air conditioning system and special grill guide structure design for improving and optimizing heat flow performance are proposed.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.40 no.5
• /
• pp.454-460
• /
• 2012

DTC(Data Terminal Controller) for UAV has been developed using FPGA. It provides the functions of Error Correction and Time-division Mux/Demux for stable data-link. RTOS VxWorks also has been used for real-time control of data-link. FPGA Design of DTC facilitates the modification and extension of various I/O device, and VxWorks ensures real-time availability of data-link control and provides flexibilities of changes of S/W design. The DTC is expected to be deployed easily for various UAV systems.

• Aerospace Engineering and Technology
• /
• v.1 no.1
• /
• pp.28-41
• /
• 2002

The purpose of this paper is to show and define the performance, the system mechanization and the algorithm of the Strapdown Inertial Navigation System(SDINS). First, navigation equations are derived in the Earth Fixed mechanization and this mechanization apply to the two kinds of inertial measurement units which consist of same fiber optic gyros and different accelerometers(SDINS-1 and SDINS-2). Those two accelerometers have the different bias. To evaluate its performance, two kinds of tests have been performed - static motionless test, and rectangle-route moving test. The results of the moving test are compared with the results of Differential GPS which has an accuracy with ±2.0mm. and are presented in this paper.

• Aerospace Engineering and Technology
• /
• v.12 no.1
• /
• pp.10-21
• /
• 2013

As helicopter technology has been upgraded, today its oceanic operation is considered to be usual. In oceanic operation of helicopter, the effect of severe wind, wave, and corrosion must be investigated and the operation procedures for safety as well as the motion of shipboard arising from maneuvers of ship must also be considered. In this paper, it describes the result of trade-off study for shipboard landing and its operation procedure including dynamic interface between ship and aircraft in ship operation and gives a simulation results to implement the oceanic operation of tilt rotor aircraft.