How Big is a Lock Number?
Here, the traditional Lock number for lifting rotors is recast in terms of a different set of parameters. This new formulation, while not changing the basic definition of the Lock number, gives additional physical insight into the design variables that influence this number. The new formulation enables one to better understand why Lock numbers fall into the range they do.
Effects of Cyclic Pitch on Time Delayed Dynamics in Coaxial Rotor Systems
Finite-state inflow methods are used to study the effect of the time-delay and adjoint dynamics of a coaxial rotor system in the presence of cyclic pitch. Finite-state inflow methods for coaxial rotors involve the use of co-states and time-delayed variables that are subject to change based on rotor spacing. Moreover, aggregate and individual blade dynamics are driven by these effects –– as well as by the cyclic pitch used in distributing loads across the rotor disk. The work presented here focuses on how variations in cyclic pitch impact the on-disk velocity and blade flapping dynamics in a coaxial rotor system at different rotor spacings.
Evaluation of Intermediate Values for Coaxial Rotor Helicopter Data Using Gradient Boosted Trees
Finite-state inflow models are one of the predominant methods used for developing flight dynamics in rotorcraft, especially for applications in flight simulators and real-time feedback systems. Finite state methods have recently been expanded to include applications for multi-rotor systems through the use of adjoint variables and time delays. However, at this point, these systems require higher computing power and more computing time, thus limiting the ability of real-time analysis. This paper investigates the feasibility of using gradient boosted trees regression modeling in XGBoostTM as a potential solution to real-time analysis.
