Therefore, the nonlinear static and dynamic characteristics also need to be considered in their design. High-aspect-ratio wings display high flexibility that cannot be expressed by using linear analysis methods, as shown in Fig. Although each propeller is relatively small, the wake of many propellers covered a large area of the main wing, resulting in an aerodynamic propeller–wing interaction. Helios Prototypes HP01 and HP03 had 14 and 10 propellers, respectively. The Helios Prototypes are representative early examples of vehicle in this class. Common features include very-high-aspect-ratio wings and propeller-based thrust generation, as shown in Fig.
Value related to node i (is equal to A, B, P, Q )Į lectric aircraft with distributed propellers are now considered for a variety of applications.
Value related to internal constraint equation Value related to external constraint equation Terms obtained from the second-order differential of the constraint equation vectorĬirculation of propeller tangential vortexĪzimuthal angle of propeller cylinder coordinate system Pitch angle of propeller or angle of attackĬirculation distribution along propeller blade Local velocity due to wake panel, propeller, dynamic motion, and freestream Propeller-induced axial and tangential velocities Lift, drag, and propeller thrust coefficientsīase vectors of propeller cylinder coordinate system A nonlinear dynamic result shows that the propeller decreases the vibration amplitude by 6.7% because the propeller-induced axial velocity enhances the aerodynamic damping. A static aeroelastic analysis on a low-speed high-aspect-ratio wing demonstrates that the propeller-induced axial velocity causes the deflection change of 5.4%.
The developed framework is validated by comparison with other formulations. An efficient propeller cylinder coordinate generation method modeling the propeller-attached wing by absolute nodal coordinate formulation with a multibody dynamic theory is also proposed. The induced velocities are considered in the wing aerodynamic force calculation using an unsteady vortex lattice method. By leveraging the smallness of the propeller, an averaged vortex cylinder method is proposed that calculates the induced velocities of the propeller vortex cylinder efficiently without suffering from a numerical singularity and loss of accuracy. Consequently, the propeller wake is modeled as a straight vortex cylinder that does not require a computationally expensive wake updating process. The high computational cost required for modeling aerodynamic interaction between the wing and propeller wake is reduced by taking advantage of the relatively slow dynamics of the wing. A nonlinear aeroelastic analysis framework for high-aspect-ratio wings that includes the aerodynamic effects of propellers is described.
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