• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.5
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• pp.511-517
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• 2009

A servo type angle of attack sensor using the null-seeking method is designed and its characteristics are analyzed in this study. Angle-of-attack in the null-seeking method is given by the probe rotation angle with respect to the body reference line when pressure difference measured in two holes on the probe becomes zero. This method provides highly accurate and uniform angle-of-attack measurements over all range. Hence, this kind of angle-of-attack sensor is adequate for unmanned aerial vehicles(UAVs). In this paper, we first analyze the requirements for developing angle-of-attack sensors. And the servo type angle-of-attack sensor is then designed and fabricated. The on-board angle-of-attack calculation algorithm is also developed. Finally, the characteristics of the developed angle-of-attack sensor are identified through MATLAB Simulink and wind tunnel tests.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.5
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• pp.60-65
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• 2011

The development of an air data acquisition algorithm has been described in the supersonic flow at the preliminary design stage with pressure data acquisition device composed of major three total pressure sensors and two static pressure sensors which are installed on the surface of a cone type supersonic inlet. Through this algorithm, Mach number, angle of attack and sideslip angle can be very easily derived with simple interpolation algorithm and predefined data tables. The available range of Mach number is 1.6 to 4.0, angle of attack, $-12^{\circ}$ to $12^{\circ}$ and sideslip angle, $-12^{\circ}$ to $12^{\circ}$. In preliminary design stage, the data tables applied to the developed algorithm are constructed with data driven by Taylor Maccoll equation. The present algorithm would be useful to get supersonic flow air data for the various aerial vehicles and their flight tests.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.04a
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• pp.215-218
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• 2011

An air data acquisition algorithm has been developed for the supersonic flow at the preliminary design stage with pressure data acquisition device composed of major three total pressure sensors and two static pressure sensors. Through this algorithm, Mach number, angle of attack and sideslip angle can be very easily derived with simple interpolation algorithm and predefined data tables. In this preliminary design stage, to verify the developed algorithm, the data tables are constructed with data driven by Taylor Maccoll equation. Furthermore, these data are compared and modified with computational results based on CFD analysis. The present algorithm would be useful to get supersonic air data for the various aerial vehicles and their flight tests.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.2 s.245
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• pp.117-125
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• 2006

In the present study the unsteady forces acting on the pitching foils such as a flat plate, NACA0010, NACA0020, NACA65-0910 and BTE have been measured by using a six-axis sensor in a circulating water tunnel at a low Reynolds number region. The unsteady characteristics of the dynamic drag and lift have been compared to the quasi-steady ones which are measured under the stationary condition. The pitching motion is available for keeping the lift higher after the separation occurs. Especially, the characteristics of the dynamic lift are quite different from the quasi-steady one at high pitching frequency regions. As the pitching frequency deceases, the amplitude of the dynamic lift becomes closer to the quasi-steady one. However, the phase remains different between the steady and unsteady conditions even at low pitching frequencies. On the other hand, the dynamic drag is governed strongly by the angle of attack.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.406-410
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• 2010

Current paper represents the air data acquisition and processing algorithm which can acquire the air data such as velocity and angle of attack by measuring the static pressure on the specific locations of a high speed aerial vehicle. Unlike the previous air data acquisition system, current system applied several pre-determined data obtained from computational fluid dynamic approach having enough sensor redundancy and fault detection ability. The verification of current algorithm was done by commercial software Matlab and Simulink.

• Journal of Aerospace System Engineering
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• v.15 no.5
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• pp.33-42
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• 2021

Modern aircraft fighters improve the maneuverability and performance with the RSS (Relaxed Static Stability) concept and therefore these aircrafts are susceptible to abrupt pitch-up in the transonic and moderate Angle-of-Attack (AoA) flight region where the shock wave is formed and the mean aerodynamic center is moved forward during deceleration. Also, the modeling of the aircraft flying in this flight region is very difficult due to complex flow filed and unpredictable dynamic characteristics and the model-based control design technique does not fully cover this problem. In this paper, we analyzed the performance of the TPMC (Transonic Pitching Moment Compensation) control based on the model-based IDI (Incremental Dynamic Inversion) and the Hybrid IDI based on the model and sensor based IDI during the SDT (Slow Down Turn) in transonic region. As the result, the Hybrid IDI had quicker response and the same maximum g suppression performance and provided the predictable flying qualities compared to the TPMC control. The Hybrid IDI improved the performance of the Over-G protection controller in the transonic and moderate AoA region