The diverse hummingbird family (Trochilidae) has unique adaptations for nectarivory, among which is the ability to sustain hover-feeding. As hummingbirds mainly feed while hovering, it is crucial to maintain this ability throughout the annual cycle-especially during flight-feather moult, in which wing area is reduced. To quantify the aerodynamic characteristics and flow mechanisms of a hummingb...

Recent developments of the aerodynamics models for the comprehensive analysis CAMRAD II are described, particularly the unsteady aerodynamic models and dynamic stall models, and the free wake geometry calculation. Three models for the unsteady aerodynamic loads in attached flow are implemented: from incompressible thin-airfoil theory, from ONERA EDLIN, and from Leishman-Beddoes. Five dynamic st...

The integration of loads analysis models using so called aerodynamic influence coefficients (AICs) is described. These AICs relate a change of normal velocity at panel control points to a change in panel pressure distribution, allowing to consider aeroelastic effects in a straight forward manner. The aerodynamic method employed for aeroelastic applications is typically the Vortex or Doublet Lat...

The results presented in this paper apply to a generic vehicle that makes use of geometry changes to modulate the heat, drag, and acceleration loads while entering a planetary atmosphere. Two structural concepts for implementing the cone angle variation, namely a segmented shell and a corrugated shell, are presented. A structural analysis of the corrugated shell configuration shows that the str...

Variable-fidelity surrogate modeling offers an efficient way to generate aerodynamic data for aero-loads prediction based on a set of CFD methods with varying degree of fidelity and computational expense. In this paper, new algorithms, such as a Gradient-Enhanced Kriging method (direct GEK) and a generalized hybrid bridge function, have been developed to improve the efficiency and accuracy of t...

Direct numerical simulations of flow past cactus-shaped cylinders are performed at Reynolds numbers of 20, 100, and 300. The results are contrasted to those from smooth cylinders at the same Reynolds numbers. The cavities in the cactus-shaped cylinders are seen to reduce the forces acting on them. At Reynolds number of 20, the drag is reduced by 22% due to reduction in the viscous forces. At Re...

Computational Fluid Dynamic (CFD) surrogates are developed to efficiently compute the aerodynamic heating and unsteady pressure loads for a structurally and thermally compliant skin panel in hypersonic flow. In order to minimize the computational overhead, the surrogates are constructed using steady-state CFD flow analysis. Unsteady terms in the aerodynamic pressure are incorporated using pisto...

In this paper, the equation of motion of an elastic 2 DoF wing model has been derived using Lagranges method. The aerodynamic loads on the wing were calculated via the Strip-Theory and the effect of compressibility was included. Wing deflections due to bending and twist motions were determined using the Assume-Mode method. The aeroelastic equations were solved numerically using the V-g method. ...