http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
비정상 용출 및 중첩 패널 기법을 이용한 비행체의 피치 동안정 미계수 예측
태명식(M.S. Tai),강선오(S.O. Kang),오세종(S.J. Oh),박동훈(D.H. Park) 한국전산유체공학회 2019 한국전산유체공학회지 Vol.24 No.1
In general, it takes large time and cost to obtain dynamic stability derivatives of flight vehicles experimentally or numerically. In this study, the pitching dynamic derivatives of aircrafts are predicted by using source-doublet panel method and evaluate its practicality. A free-wake panel method is used for unsteady aerodynamic analysis of an aircraft in forced harmonic pitch oscillation. A treatment for wake-body interaction is applied to take into account the effect of wake from a main wing on a fuselage or tail wing. Calculations are carried out for a single rectangular wing, standard dynamic model(SDM), and DLR-F12 geometries. The dynamic derivatives are predicted based on the time history of the normal force and pitching moment. The unsteady panel method is validated by using numerical and experimental data in literatures and the results of Euler computation using commercial CFD code. For both the time history and predicted dynamic derivatives, the results show reasonable agreement with available experimental data and CFD results. The effect of Mach number and reduced frequency is examined for the SDM case. Within the Mach number range studied, the dynamic derivatives increase with Mach number which is consistent with the tendency observed in the previous studies. The dynamic derivatives are found to be relatively insensitive to the reduced frequency. The results show that the method of the present study provides reasonable accuracy and good efficiency for estimating the dynamic derivatives.
로터 공력 해석을 위한 Actuator Surface Method 개선 연구
박재영(J.Y. Park),강선오(S.O. Kang),태명식(M.S. Tai),오세종(S.J. Oh),박동훈(D.H. Park) 한국전산유체공학회 2019 한국전산유체공학회지 Vol.24 No.2
In this study, improvements on up-to-date actuator surface method are proposed to enhance the prediction capability and universality for rotor aerodynamic analysis. In order to improve accuracy for analysis of high-solidity rotor, the correction equation for reference line velocity was newly derived to take into account influences of neighboring blades. To describe more realistic flow field and wake around blades, source-doublet panel method was adopted to calculate the momentum source distribution along chord-wise direction which reflects the characteristics of sectional airfoil and flow condition. The validity of proposed methods is evaluated by carrying out the analyses for rectangular wing and open rotor, and comparing with available experimental and computational results. It is confirmed that suggested methods can provide improvement on prediction of velocity field and wake trajectory, as well as aerodynamic performance.