• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.6
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• pp.31-38
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• 2002

This paper presents the analysis of the flight test data measured by the sensors installed on a four-seat canard aircraft. The inherent stall proof characteristics of canard aircraft was verified from the stall test. The dihedral effect, adverse yaw and roll control power were examined and the neutral point that determines the longitudinal stability of the aircraft was investigated. The dynamic characteristics such as dutch roll mode were also examined. Without relying on the parameter identification method, the aerodynamic derivatives or the relations between the aerodynamic derivatives were obtained by analyzing the steady state flight data.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.3
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• pp.220-228
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• 2008

In this study the aerodynamic characteristics of a canard-controlled missile with freely spinning tailfins were investigated by using a semi-empirical method and a CFD code. The mean aerodynamic coefficients for the rolling and roll damping moments were first calculated and then used to predict the roll-rate of freely spinning tailfins. The calculation of roll-rate in the CFD code was carried out by combining a Chimera overset grid system and 6-DOF analysis module. The predicted roll-rate was in good agreement with the experimental data for the roll and yaw canard control inputs. It was also shown that the results are in good agreement with the prediction by a CFD code. This indicates that the semi-empirical method can be used to predict the roll-rate of a canard-controlled missile with freely spinning tailfins.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.6
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• pp.45-51
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• 2003

This paper presents a method to improve lateral stability of a four-seat canard aircraft, Velocity-173. Longitudinal stability of Velocity-173 is rather good, but lateral stability is relatively poor. A small panel which increases the area of vertical tail is designed and manufactured. In a design process, AAA(Advanced Aircraft Analysis) is used to predict the change in stability. Flight test is performed to validate the effect of a small panel attached under the vertical panel. Maximum likelihood estimation method is used to extract lateral controllability / stability derivatives from flight test data. This work validates the effect of a small panel attached under the vertical tail.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.126-129
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• 2008

In this study the aerodynamic characteristics of a canard-controlled missile with freely spinning tailfins were investigated by using a CFD code. The aerodynamic coefficients and roll-rate of freely spinning tailfins were calculated by an analysis of 6-DOF and the Euler code. Results were in good agreement with experimental data, and the roll-rates of freely spinning tailfins were also in good agreement with the experimental data for the roll and yaw canard control inputs. This indicates that the CFD Euler code can be applied to predict the canard-controlled missile with freely spinning tailfins.

• Aerospace Engineering and Technology
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• v.2 no.1
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• pp.22-28
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• 2003

This paper presents a method for estimating static aerodynamic derivatives by analyzing data obtained from the flying quality evaluation test of a small canard aircraft. The aerodynamic derivatives extracted from maximum likelihood estimation method and from the proposed method in this paper are compared in the same polt. Reliable static aerodynamic derivatives were extracted from a limited number of the flight tests by the proposed method. The parameter data obtained from this method can be used as reference for the conventional parameter identification methods such as maximum likelihood estimation method.

• Journal of computational fluids engineering
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• v.14 no.4
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• pp.48-55
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• 2009

In this study, roll lock-in phenomena of freely spinning tailfins were investigated by a CFD code. To analyze a motion of freely spinning tailfins, this research use a Chimera method, an Euler code and a 6 degrees of freedom analysis. The numerical results of aerodynamic characteristics and roll rates of a canard-controlled missile with freely spinning tailfins show a good agreement with wind tunnel test results. Using the roll rates calculation result of freely spinning tailfins, roll lock-in phenomena is confirmed. Roll lock-in phenomena and Roll lock-in states can be predicted through effects of the induced vortex of the canards control and the analysis of the rolling moments of tailfins due to the bank angle.

• Journal of computational fluids engineering
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• v.8 no.4
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• pp.26-33
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• 2003

Smart UAV Development Program, one of the 21c Frontier R&D Program sponsored by MOST(Ministry of Science and Technology), was launched in 2002 As an air vehicle for the Smart UAV, CRW(Canard Rotor/wing) concept was one of the candidates compared in trade-off study. The CRW concept has not only been proven completely but its aerodynamic characteristics not known in detail yet. Two calculation methods were adopted in this study to obtain aerodynamic data for the CRW First method was the superpose DATCOM method which is capable of three lifting sufaces, and second one is the full Navier-Stokes computation around CRW configuration using overset grid method. Basic aerodynamic characteristics of the CRW configuration was analyzed and the minimum drag level with lift to drag ratio is presented. The peculiar flow characteristics around rotor/wing and hub were also examined and considered in the configuration design.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.9
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• pp.57-64
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• 2004

The Purpose of this paper is to obtain the lateral-directional controllability and stability derivatives of the Velocity-173 from the flight test data and to simulate motion of the aircraft by using In-flight Real-Time Parameter Estimation Techniques. In this paper, the results of the In-Flight Real-Time parameter Estimation Techniques are compared with the results of the Advanced Aircraft Analysis. As a result, Estimation by using In-Flight Real-Time Parameter Estimation Techniques can be done rapidly and their results are reliable.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.9
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• pp.849-855
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• 2010

This paper investigated the roll lock-in phenomena of a canard-controlled missile with freely spinning tailfins by applying Falanga's roll-rate equation. To confirm and validate the accuracy of the results of the roll-rate and roll lock-in prediction for freely spinning tailfins, the results were compared with Blair's wind tunnel test data. For calculation of the roll-rate of freely spinning tailfins, rolling moment coefficients of the tailfins were obtained from the wind tunnel test data and roll-damping coefficients were calculated by missile DATCOM. The roll-rate and roll lock-in of the freely spinning tailfins were calculated by applying these values to the roll-rate equation for freely spinning tailfins. The calculation results showed good agreement with the wind tunnel test data, and the roll lock-in could be anticipated as well.