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General Statements
Published in Pylyp Volodin, Blade Element Rotor Theory, 2023
A rotor system is defined here as the combination of rotary wings (blades) that generate the aerodynamic lift forces in order to: support the weight of an aircraft in a flight; counteract the aerodynamic drag of the aircraft at forward flight; and control over the aircraft motion. A rotorcraft is defined here as a heavier-than-air aircraft which uses such a rotor system to perform a flight in an airspace. Generally, a rotor system transforms energy of a rotorcraft engine into energy required for a rotorcraft flight in an airspace. It is assumed hereafter that a rotor system has defined upper and below sides; an engine of a rotorcraft is usually located below the rotor system.
Economics
Published in Thomas Corke, Robert Nelson, Wind Energy Design, 2018
The rotor hub is the structure on which the rotor blades mount. Since the rotor hub has to support the weight of the rotor, its mass is expected to scale approximately linearly with the mass of the rotor. This is in fact the case as given by the following relation[6]. Hub Mass = 0.954Single Blade Mass+5680.3 $$ {\text{Hub Mass = 0}}{\text{.954}}\left( {{\text{Single Blade Mass}}} \right) + 5680.3 $$
Emergency procedures
Published in Henry H. Perritt, Eliot O. Sprague, Domesticating Drones, 2016
Henry H. Perritt, Eliot O. Sprague
Autorotation is an aerodynamic phenomenon in which the upward flow of air through rotor blades causes the blades to spin and to generate lift despite the absence of torque from the propulsion system. Without power the aircraft descends rapidly, making autorotation possible. The phenomenon was first analyzed in the nineteenth century by the Scottish physicist James Clerk Maxwell, most famous for first formulating a theory of electromagnetic radiation. Maxwell developed the aerodynamic theory of autorotation based on longstanding observations by others who watched maple seeds falling from a tree spin as they fall to the ground.
Real-Time Performance Analysis of FOI-PD Controller for Twin Rotor MIMO System
Published in IETE Technical Review, 2019
Debdoot Sain, Subrat Kumar Swain, Ayan Saha, Sudhansu Kumar Mishra, Sarbani Chakraborty
The TRMS kit from Feedback Instruments (Model no. 33–220) is a highly non-linear MIMO system. The voltages supplied to the rotors are the two inputs and the horizontal and vertical angles are the two outputs of the system. Aerodynamically, the TRMS consists of two types of rotors: one is the main rotor, and the other is the tail rotor. Both the rotors are fixed at the two ends of a beam and are driven by two dc motors. It is counter balanced by another pivoted beam with a weight attached at its end. A lifting force is produced by the main rotor to elevate the beam vertically and make a rotation around the pitch axis. The function of the tail rotor is to turn the beam left or right around the yaw axis. The system has 2 degrees of freedom (2 DOF), i.e. it can move freely in the vertical and horizontal directions. Though the TRMS bears a strong resemblance to an actual helicopter, some significant modifications have been made [24]. The TRMS kit is also equipped with an electrical unit to interface the kit to a computer with a PCL-812 I/O board. Software tools like MATLAB, Simulink are installed in the computer to perform the control experiments and implement the controllers in real-time. The mechanical and electrical units provide a complete control system setup for the TRMS kit and are presented in Figure 1.