Open Access
Rotorcraft Aerodynamics Models for a Comprehensive Analysis
TLDR
In this paper, a force balance method for calculating section loads of a bearingless rotor rotor was proposed, and the results were compared with the results from a full-scale wind tunnel test.Abstract:
Recent developments of the dynamics models for the comprehensive analysis CAMRAD II are described, specifically advanced models of the geometry and material for the beam component, and a force balance method for calculating section loads. Calculations are compared with measurements for beams undergoing large deflection. Bearingless rotor stability and bending loads calculations are compared with the results from a full-scale wind tunnel test. With a reasonable number of beam elements representing the rotor blade, any large deflection effects are captured by the rigid body motion (which is always exact), and a second-order model of the beam element elastic motion is adequate. The deflection method gives unacceptable results for the structural loads in practical cases, and even with uniform blade properties. The force balance method described here gives good results for blade load, without requiring a large number of nodes.read more
Citations
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Journal ArticleDOI
Navier-Stokes and Comprehensive Analysis Performance Predictions of the NREL Phase VI Experiment
TL;DR: A vortex lattice code, CAMRAD II, and a Reynolds-Averaged Navier-Stoke code, OVERFLOW-D2, were used to predict the aerodynamic performance of a two-bladed horizontal axis wind turbine.
Journal ArticleDOI
Rotor Airloads Prediction Using Loose Aerodynamic/Structural Coupling
TL;DR: In this article, a computational fluid dynamics (CFD) code and rotorcraft computational structural dynamics (CSD) codes are coupled to calculate helicopter rotor airloads across a range of flight conditions.
Proceedings ArticleDOI
Mars Helicopter Technology Demonstrator
J. Balaram,Timothy Canham,Courtney Duncan,Matthew P. Golombek,Håvard Fjær Grip,Justin N. Maki,Amelia Quon,Ryan A. Stern,David Zhu +8 more
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Concept Vehicles for VTOL Air Taxi Operations
TL;DR: In this paper, the design of a single passenger (250-lb payload), 50-nm range quadrotor with electric propulsion, six-passenger (1200-lb payload), 4x50 = 200nm range side-by-side helicopter with hybrid propulsion, and a fifteen-passengers (3000-llb payload) with turbo-electric propulsion.
Journal ArticleDOI
Performance Analysis of a Utility Helicopter with Standard and Advanced Rotors
TL;DR: In this article, the performance of the UH-60 Black Hawk helicopter with both standard and advanced rotors is compared with calculations obtained using the comprehensive helicopter analysis CAMRAD II in general, the calculated power coefficient shows good agreement with the flight test data However, the accuracy degrades at high gross weight for all of the configurations.
References
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Book
Variational Methods in Elasticity and Plasticity
TL;DR: In this article, the Statique Reference Record was created on 2004-09-07, modified on 2016-08-08, and was used for Elasticite and Plasticite.
Nonlinear equations of motion for the elastic bending and torsion of twisted nonuniform rotor blades
Dewey H. Hodges,Earl H. Dowell +1 more
TL;DR: In this article, the Hamilton's principle and the Newtonian method are used to derive the equations of motion for long, straight, slender, homogeneous, isotropic beams undergoing moderate displacements.
Journal ArticleDOI
A mixed variational formulation based on exact intrinsic equations for dynamics of moving beams
TL;DR: In this paper, a nonlinear intrinsic formulation for the dynamics of initially curved and twisted beams in a moving frame is presented, which is written in a compact matrix form without any approximations to the geometry of the deformed beam reference line or to the orientation of the intrinsic cross-section frame.