• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.3
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• pp.274-279
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• 2010

The present work is to analyze the longitudinal static stability and the drop trajectory of fighter aircraft's external fuel tank, of which horizontal fin is modified as the 20% scale down size compared with the original one. The analytical results to the pitching stability of external fuel tank using a thin airfoil's aerodynamic force data show the corresponding tendency to results of wind tunnel experiment. Results of trajectory simulation by the 6 degree of freedom equations of motion, comparing with drop trajectories of wind tunnel experiment, are shown that aircraft's attitude affects strongly on horizontal movement but not on the vertical movement. Those results give the reliability to aircraft safety when the external fuel tank with the 20% reduced horizontal fins is released from aircraft based on the flight manual.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.2
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• pp.15-22
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• 2011

Unlike most aerodynamic wind-tunnel, Scramjet Engine Test Facility(SETF) of Korea Aerospace Research Institute should simulate enthalpy condition at a flight condition. SETF is a blow-down type, high-enthalpy wind tunnel. To attain a flight condition, a highly stagnated air comes into the test cell through a supersonic nozzle. Also, an air ejector of the SETF is used for simulating altitude conditions of the engine, and facility starting. SETF has a free-jet type test cell and this free-jet type test cell can simulate a boundary layer effect between an airplane and engine using facility nozzle, but it is too difficult to predict the nature of the facility. Therefore it is required to understand the starting characteristics of the facility by experiments. In this paper, the starting characteristics of the SETF and modifications of the ejector are described.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.1
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• pp.1-9
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• 2007

Numerical simulation is conducted to investigate aerodynamic force generation mechanism for the "figure-of-eight" motion of Dipteran fly, Phormia-Regina. Wing trajectory is referred to experimental result, which was observed from the tethered flight under freestream condition. Numerical simulation shows that the lift is mainly generated during downstroke motion and the large amount of thrust is generated abruptly at the end of upstroke motion. In the present work, vortical structure in the wake and the pressure field around the airfoil are examined to understand the generation of lift and thrust. Consequently, the lift generation is related with the leading edge vortex which is developed by an effective angle of attack. And the thrust generation can be explained by vortex pairing in the flow field and by vortex staying in the pressure field.

• Aerospace Engineering and Technology
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• v.3 no.1
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• pp.170-178
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• 2004

This paper deals with six degree-of-freedom HILS(hardware-in-the-loop-simulation) of KSR-III rocket using a TAFMS(three axis flight motion simulator). This TAFMS HILS test is accomplished before main HILS tests in order to verify the control stability in the presence of TAFMS dynamic effects. The TAFMS HILS test includes initial attitude holding tests for INS initial alignment procedures, timer synchronization tests with an auxiliary lift-off signal, real-time calibration tests using an external thermal recorder, open-loop TAFMS operating tests, and final closed-loop TAFMS HILS tests using the TAFMS attitude measurements as inputs to the closed control loop. The HILS tests are accomplished for several flight conditions composed with nominal flight condition, TWD effect added condition, slosh modes and/or bending modes existing condition, and windy condition, etc.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.451-458
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• 2010

Unlike most aerodynamic wind-tunnel, Scramjet Engine Test Facility(SETF) of Korea Aerospace Research Institute should simulate enthalpy condition at a flight condition. SETF is a blow-down type, high-enthalpy wind tunnel. To attain a flight condition, a highly stagnated air comes into the test cell through a supersonic nozzle. Also, an air ejector of the SETF is used for simulating altitude conditions of the engine, and facility starting. SETF has a free-jet type test cell and this free-jet type test cell can simulate a boundary layer effect between an airplane and engine using facility nozzle, but it is too difficult to predict the nature of the facility. Therefore it is required to understand the starting characteristics of the facility by experiments. In this paper, the starting characteristics of the SETF and modifications of the ejector are described.

• Journal of Korean Society of Forest Science
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• v.90 no.1
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• pp.139-145
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• 2001

Behavior of Matsucoccus thunbergianae Miller and Park males immediately after emergence from their cocooning site, and meteorological factors affecting the responsiveness of the flying males to synthetic pheromone were studied. On Pinus thunbergii saplings, newly emerged males walked around to locate females. The males lanuched themselves into flight after up to three times of copulation. Without the presence of females, the males took off within five minutes whereas when the females were placed nearby but copulation was artifically prohibited the males did not take off. In a wind tunnel, the presence of female pheromone discouraged male take off. More males were flying in sunny area than in shade, but light intensity had no effect on the responsiveness of males toward the pheromone source. Wind speed was the main meteorological factor that affected the male responsiveness. Most males, after hitting the substrate near pheromone source with various posture, stood on their feet and approached the source.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.7
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• pp.479-487
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• 2022

This paper presents the control and guidance algorithm of a KAU-SPUAV(Korea Aerospace University - Solar Powered Unmanned Aerial Vehicle) which is designed and developed in Korea Aerospace University. Aerodynamic coefficients are calculated using the vortex-lattice method and applied to the aircraft's six degrees of freedom equation. In addition, the thrust and torque coefficients of the propeller are calculated using the blade element theory. An altitude controller using thrust was used for longitudinal control of KAU-SPUAV to glide efficiently when it comes across the upwind. Also describes wind estimation technic for considering wind effect during flight. Finally, introduce some guidance laws for endurance, mission and coping with strong headwinds and autonomous landing.

• The Korean Journal of Air & Space Law and Policy
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• v.32 no.1
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• pp.201-224
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• 2017

The main subject of this article focused on the legal status of the military aircraft in the high seas. For this the legal status of the military aircraft, the freedom of overflight, the right of hot pursuit, the right of visit and Air Defense Identification Zone (ADIZ) were dealt. The 1944 Chicago Convention neither explicitly nor implicitly negated the customary norms affecting the legal status of military aircraft as initially codified within the 1919 Paris Convention. So the status of military aircraft was not redefined with the Chicago Convention and remains, as stated in the 1919 Paris Convention, as a norm of customary international law. The analyses on the legal status of the military aircraft in the high seas are found as follows; According to the Article 95 of the 1982 United Nations Convention on the Law of the Sea (UNCLOS) warships on the high seas have complete immunity from the jurisdiction of any State other than the flag State. We can suppose that the military aircraft in the high seas have also complete immunity from the jurisdiction of any State other than the flag State. According to the Article 111 (5) of the UNCLOS the right of hot pursuit may be exercised only by warships or military aircraft, or other ships or aircraft clearly marked and identifiable as being on government service and authorized to that effect. We can conclude that the right of hot pursuit may be exercised by military aircraft. According to the Article 110 of the UNCLOS a warship which encounters on the high seas a foreign ship, is not justified in boarding it unless there is reasonable ground for suspecting that: (a) the ship is engaged in piracy, (b) the ship is engaged in the slave trade, (c) the ship is engaged in an unauthorized broadcasting and the flag State of the warship has jurisdiction under article 109, (d) the ship is without nationality, or (e) though flying a foreign flag or refusing to show its flag, the ship is, in reality, of the same nationality as the warship. These provisions apply mutatis mutandis to military aircraft. As for Air Defence Identification Zone (ADIZ) it is established and declared unilaterally by the air force of a state for the national security. However, there are no articles dealing with it in the 1944 Chicago Convention and there are no international standards to recognize or prohibit the establishment of ADIZs. ADIZ is not interpreted as the expansion of territorial airspace.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.3
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• pp.225-236
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• 2017

In this paper, a simulation test bed is presented which operates to provide full-scale simulation of airborne multi-function phased array radars. This simulation test bed provides a capability to evaluate the target tracking performance. To realize aircraft operation scenario, we developed 6DOF aircraft dynamics model which can generate trajectories and attitude of an aircraft. This procedure includes steady state flight trim search, autopilot design, and aircraft guidance command design. Also, the radar-environment integrated simulator includes target detection/measurement model and tracking filter. Developed simulator is validated by creating an air-to-air scenario.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.47 no.2
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• pp.55-59
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• 2010

Recently it is tried to use load control model for maneuver moving object. MIN design method proposed to solve control problem of nonlinear system using load concept. The Min design method shows direct method for finding control value on the load control model. In this paper, is shown realization free falling model using nonlinear load control model and analysis of load values acting falling object according to disturbance. And made a trajectory according to acting load values due to disturbance. This paper's result is able to be applied to design algorithm for improvement accuracy of MLRS, GPS air-to-surface missile(ASM) and returning spacecraft with nonlinear model predictive control.