• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2005.11a
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• pp.141-146
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• 2005

This paper presents a theoretical analysis of a ramjet and scramjet engine according to flight Mach numbers. The main objective of this study is to give physical understanding on the performance parameters and to provide a more unified treatment of the fundamentals of ramjet and scramjet propulsion, mainly based on analytical methods. The effects of flight Mach number, inlet characteristics, and combustion on the performance of ramjet and scramjet are analysed. The cycle analysis are conducted on both combustors with constant pressure and with constant cross-section area, on which comparisons are made. Also the optimal Mach number at the entry of the combustor is studied.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2005.11a
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• pp.479-483
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• 2005

BBU is the weapon system for the extension of range through the reduction of base drag in 155mm. It has been mass-produced since 2000. The purpose of this research is productivity increase through the reduction of process lead time. Development process is as follows. First, formulation tests about propellent and liner, Second, spin test and final firing test about end products.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.777-780
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• 2011

The supersonic wind tunnel is a common facility to studies the aerodynamic phenomenon around the high speed vehicle or weapon system whose operating speed is greater than sonic speed. In this study, a design procedure and selecting the components of a new supersonic wind tunnel whose nozzle exit is $125mm{\times}100mm$ is considered. An operating test of this wind tunnel is being conducted to compare the result with the design values, mach number, etc.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.756-762
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• 2011

A gas deflector cooling system plays an important role in the suppression of shock wave generated during the ignition of a launch vehicle engine. Also, this system decrease a large vibration of damaging the payload and structure of the launch vehicle. The gas deflector cooling system in the launch pad of NARO space center was constructed to directly inject water into the plume of the launch vehicle engine. The flight test result of NARO space launch vehicle showed that this method had a good performance on the viewpoint of cooling the gas deflector.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.139-142
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• 2011

A water-flow test for acceptance verification is carried out for a nonimpinging-type injector prior to the design-performance verification of hydrazine thruster under development. The injector used in the experiment is to be equipped on the hydrazine thruster producing 70 N of nominal thrust at an inlet pressure of 24.6 $kg_f/cm^2$. It is observed that there exist varying characteristics of atomization among the injector-nozzle orifices caused by a fabrication error which can be judged from a microscopic standpoint. On the other hand, all of the injector orifices are placed within the design criteria in an injection-angle performance.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.544-547
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• 2011

This paper describes on hardware simulation of passive power control of propulsion system for electric propulsion aircraft of KARI. The propulsion system uses hybrid power system that is composed of solar cell, fuel cell and battery. The fuel cell is replaces by simulator due to its difficulty in handling while the other components are the same as that will be used on board. As the result, reliable power supply for propulsion is confirmed and each power source is well operated showing its characteristics.

• Journal of Aerospace System Engineering
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• v.10 no.3
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• pp.39-43
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• 2016

In this paper, a wind-tunnel test is accomplished to investigate the roll characteristics of a variable-span wing flying inside a channel. The factors that affect the roll characteristics of the wing were identified by analyzing the measured data; accordingly, when the wing is flying without both the ground and sidewall effects, the asymmetric wing extension causes the roll moment. Both the ground and the sidewall can increase the roll moment, but when the wing is affected by both the ground and the sidewall, the roll moment does not increase as much as the case where the wing is only affected by the ground. Also, the aerodynamic characteristics of the flying wing inside a channel are the nonlinear function of the wing height and the gap between the wingtip and the sidewall, both of which should be considered in a study of the stability and the flight control of the wing-in-ground effect of the vehicle flying inside a channel.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.10
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• pp.1085-1093
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• 2010

This paper proposes a multiple filter for reduction of received signal fluctuation and enhancement of step altitude edge detection in FMCW radar altimeter. The proposed filter was composed of alpha-trimmed mean filter, frequency variation limiter, and 1/3 order static filter. Simulations by analysis of received signal show that the proposed filter provides better performance than moving average and standard median filters with error reduction. In particular, the proposed filter was improved in the ability of reducing fluctuation for ground hovering.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.5
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• pp.460-465
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• 2007

This paper deals with the Fine Digital Sun Sensor (FDSS) for Science & Technology Satellite 2(STSAT-2). The FDSS was firstly developed by using CMOS-Image sensor(CIS) in South Korea. This paper will describe the configuration of the FDSS, the design of the optical part, the analysis result of the optical characteristics of the sunlight, and the calibration result measured by solar simulator.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.4
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• pp.512-519
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• 2012

This paper proposes a 3-D pose (positions and orientations) estimation system based on the recognition of circular ring patterns. To deal with monocular vision-based pose estimation problem, we specially design a circular ring pattern that has a simplicity merit in view of object recognition. A pose estimation procedure is described in detail, which utilizes the geometric transformation of a circular ring pattern in 2-D perspective projection space. The proposed method is evaluated through the analysis of accuracy and precision with respect to 3-D pose estimation of a quadrotor-type vehicle in 3-D space.