Multiple-Fidelity Modeling of Interactional Aerodynamics

Abstract

The interaction of trailing vortices with lifting surfaces is investigated using two levels of modeling fidelity. A RANS-based computational fluid dynamics solver is considered as the high-fidelity computational model and a vortex panel method with a propeller model is considered as the low-fidelity computational model. The high-fidelity model is first validated against available experimental data obtained from the interaction of a trailing vortex generated by an upstream wing with a downstream wing. The ability of the models to represent the development of the vortex wake and integrated loads is assessed for a number of parametric configurations, including a case in which the vortex core directly impacts the wing surface. Following this, configurations of an isolated propeller and a wingmounted propeller are studied. In all of these cases, the high-fidelity model is effective in predicting the details of the flow and integrated airloads. The low-fidelity model, while less accurate is shown to successfully represent integrated quantities well at orders of magnitude less cost than the high-fidelity model, justifying its role as a viable tool in design and trajectory planning applications.

Quad-Rotor Flight Simulation in Realistic Atmospheric Conditions

“…In this work, each rotor of a quad-copter is modeled individually using fundamental potential flow theory, while taking into account tools from helicopter rotor aerodynamic modeling. As a prototypical example, Mishra et al [38] utilized an adaptation of extended blade element momentum theory from [39] and validated their steady thrust predictions with CFD simulations. However, their method was primarily defined for propellers of fixed-wing aircraft for which the flight condition is essentially similar to vertical flight of rotary-wing aircraft.…”

Genetic Algorithm-Based Tuning of Backstepping Controller for a Quadrotor-Type Unmanned Aerial Vehicle

“…Equations (34)- (37) represent the control signals necessary for path tracking. On the other hand, Equations (38) and (39) are used to determine the warping and pitch angles necessary for tracking the reference. The only value that remains unknown is α, so tuning of the controller is required.…”

“…UAV systems have been studied as a whole or in subsystems (for example, tilt control). The challenge of these vehicles is that they are nonlinear, subacted, and multivariable systems, subject to unpredictable disturbances such as the interaction of the rotor flow with the quadrotor chassis or atmospheric turbulence [26][27][28][29][30][31][32][33][34][35][36][37][38][39], so that classic control (linear and invariant over time) has limited results where instabilities can occur when the system moves away from equilibrium.…”

Aerodynamic Modeling of a Flying Wing Featuring Ludwig Prandtl’s Bell Spanload

“…The main contribution of this paper is seen to be the prediction of the salient feature of the bell spanload, considered to be the proverse yaw, using variable fidelity methods. While a comparison of these and other methods in terms of fidelity has been shown in the past in general in References [14][15][16][17][18][19][20], limited resources are available for study of aircraft similar to this one, with some examples in References [21,22]. This manuscript aims to study the difference in predictions from the two methods utilized for this specific aerodynamic characteristic, described by the C N δa control derivative.…”