• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.2
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• pp.165-170
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• 2007

During the conceptual design phase of a wing-body-canard type fighter class aircraft, as a method of maneuverability enhancement for an aircraft, effects of canard-leading edge flap scheduling have been studied. In this study, corrected supersonic panel method has been used to predict the drag polar characteristics due to canard-leading edge flap deflections in the high speed regime. Utilizing the predicted drag polar curves, the canard-leading edge flap scheduling laws have been established. These scheduling laws are the relation of canard-leading edge flap deflections and the flight conditions to maximize the lift-drag ratio. Based on the results obtained from the canard-leading edge flap scheduling, the present method has shown to be useful to enhance the maneuverability of wing-body-canard type fighter class aircraft.

• Journal of the Korea Institute of Military Science and Technology
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• v.2 no.2
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• pp.70-82
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• 1999

During the aircraft conceptual design stage, rapid aerodynamic analyses over various configurations are required. Hence, empirical and analytical methods play important roles in predicting the aero-dynamic characteristics. In this study, total drag estimation method based on empirical and analytical approaches is developed. By comparing with the results of the wind tunnel experiment and existing prediction methods, it is demonstrated that the developed method is accurate and useful in predicting total drag for the whole Mach number range.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.4
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• pp.308-315
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• 2007

This study is performed to find out the climb performance of light airplane, Chang Gong-91, as a part of flight test to acquire the certification. Chang Gong-91 is a 5-passenger light aircraft of normal category with single reciprocating engine, and the first officially certified by Korean Ministry of Construction and Transportation in 1993. These flight test procedure and data for climb performance are used to get type certification. We have got maximum climb rate for operating altitude, best angle of climb speed, best rate of climb speed, and absolute ceiling of Chang Gong-91 using drag polar data reduction method from sawtooth climb flight data. Also we compare the form drag coefficient from the results of climb performance and Oswald's effectiveness coefficient to design values using lift-drag curve of light airplane.

• International Journal of Aeronautical and Space Sciences
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• v.4 no.1
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• pp.19-25
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• 2003

A low speed wind tunnel test for the canard airplane model was conducted in KARI LSWT. To measure the required level of accuracy, the image system was applied for all elevator deflection and different canard incidence conditions. By doing so, the difference in aerodynamic characteristics between the forward swept and straight canards can be precisely evaluated, and the pros and cons of both canards arrangements can be discussed. Compared with both canard configurations at the same incidence angle setting, the straight canard has benefits in lift and drag, and the slope of pitching moment increases more moderately than the forward swept canard. The listed data and discussion would be useful to whom wants to design a canard airplane.

• Ocean and Polar Research
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• v.26 no.3
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• pp.481-486
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• 2004

A portable apparatus mounting Acoustic Doppler Current Profilers (ADCP) to any small boat was developed to effectively measure currents in shallow and narrow coastal seas like the west coasts of Korea. Characteristics of the apparatus is that an underwater fish-shaped body protecting an ADCP is designed to reduce the drag during the cruise, which can be freely mounted and detached from a boat with a clamp. Several cruise outputs prove themselves that the apparatus is properly designed for the intended purpose, to minimize air bubbles and to control the submerged depth of the sensor.

• Journal of Astronomy and Space Sciences
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• v.22 no.4
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• pp.463-472
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• 2005

In this paper, the dynamic model development for interplanetary navigation has been discussed. The Cowell method for special perturbation theories was employed to develop an interplanetary trajectory propagator including the perturbations due to geopotential, the Earth's dynamic polar motion, the gravity of the Sun, the Moon and the other planets in the solar system, the relativistic effect of the Sun, solar radiation pressure, and atmospheric drag. The equations of motion in dynamic model were numerically integrated using Adams-Cowell 11th order predictor-corrector method. To compare the influences of each perturbation, trajectory propagation was performed using initial transfer orbit elements of the Mars Express mission launched in 2003, because it can be the criterion to choose proper perturbation models for navigation upon required accuracy. To investigate the performance of dynamic model developed, it was tested whether the spacecraft can reach the Mars. The interplanetary navigation tool developed in this study demonstrated the spacecraft entering the Mars SOI(Sphere of Influence) and its velocity .elative to the Mars was less than the escape velocity of the Mars, hence, the spacecraft can arrive at the target planet. The obtained results were also verified by using the AGI Satellite Tool Kit. It is concluded that the developed program is suitable for supporting interplanetary spacecraft mission for a future Korean Mars mission.