Nam Song Pak,
Sol Song Pak,
Won Hak Kim,
- Faculty, Department of Mechanics, Kim Il Sung University, Pyongyang, Korea
- Faculty, Department of Mechanics, Kim Il Sung University, Pyongyang, Korea
- Faculty, Department of Mechanics, Kim Il Sung University, Pyongyang, India
Abstract
The aerodynamic derivatives can be calculated from the unsteady hydrodynamic forces experienced by the harmonic-oscillating vehicle. Until now, unsteady flow field analysis in aerodynamic derivative calculations has been applied mainly to thin bodies based on potential theory MSC. Nastran is a typical application based on potential theory MSC. Natran can calculate the aerodynamic derivatives of the vehicle relatively well in the subsonic region, but in the supersonic region, the fuselage element is not available, so the calculation is done by converting the fuselage to panel elements projected onto a flat plate. But the airfoil profile cannot be reflected in all velocity regions, and the exact calculation cannot be carried out in the transonic region, limiting the perturbation velocity potential method. Analyzing unsteady flow fields by numerical solution of Euler’s equations using CFD methods can overcome the limitations of potential theory, but the computational effort is too expensive to apply to practical problems. On the other hand, in the calculation of aerodynamic derivatives, the harmonic vibration amplitude of the considered vehicle and the perturbations of the fluid resulting from it can be calculated by considering the infinitesimal quantities. Hence, in this study, the time-linearized unsteady Euler equations are numerically solved in the frequency domain by the finite volume method to perform unsteady flow field analysis. This can overcome the limitations of potential theory and can be applied to practical problems by reducing the computational effort significantly, since the transient problem is considered as a stationary problem in the frequency domain. Nastran can perform aerodynamic derivative calculations of aircraft in the aeroelastic analysis module. The aeroelastic phenomena are composed of the interaction of the inertial forces of the aircraft, the elastic forces of deformable bodies and the aerodynamic forces. Therefore, structural analysis and aerodynamic calculations must be combined. Here, we consider MSC. The aerodynamic theories based on Nastran and the interpolation methods that interconnect structural deformation and aerodynamic forces are described in detail.
Keywords: Vibration, airfoil, fluid analysis, angle of attack, non-linear
[This article belongs to Journal of Experimental & Applied Mechanics ]
Nam Song Pak, Sol Song Pak, Won Hak Kim. Study on the Method of Constructing a System of Linear Equations for Calculating Aerodynamic Derivatives. Journal of Experimental & Applied Mechanics. 2025; 16(03):14-24.
Nam Song Pak, Sol Song Pak, Won Hak Kim. Study on the Method of Constructing a System of Linear Equations for Calculating Aerodynamic Derivatives. Journal of Experimental & Applied Mechanics. 2025; 16(03):14-24. Available from: https://journals.stmjournals.com/joeam/article=2025/view=233314
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| Volume | 16 |
| Issue | 03 |
| Received | 17/07/2025 |
| Accepted | 13/08/2025 |
| Published | 26/09/2025 |
| Publication Time | 71 Days |
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