Analyzing the propeller aerodynamic performance is of vital importance for research and improvement unmanned aerial vehicles. This paper presents design requirements a rotorcraft vehicles an analysis model calculating performance. Based on blade element momentum theory, force analyzed used. The symmetric airfoil NACA 0012 used as example to verify validity model. An experimental system designed...

Abstract: Wind turbine blades have to withstand the rigorous test of 20–25 years of service. Fatigue testing is an accurate method used to verify blade reliability. Multi-point excitation could better fit the fatigue damage distribution, which reduces the power output of a single exciter and saves testing energy consumption. The amplitude, phase, and frequency characteristics of the fatigue tes...

The primary goal of the this paper is to summarize field demonstrations of the feasibility of detecting changes in blade and shaft natural frequencies (such as those associated with a blade or shaft crack) on operating machinery using non-contact, nonintrusive measurement methods. This paper primarily addresses the results of application of this nonintrusive torsional vibration sensing to: a la...

We study the chromodynamical gauge symmetry in relation to the internal spin structure of the nucleon. We show that 1) even in the helicity eigenstates the gauge-dependent spin and orbital angular momentum operators do not have gauge-independent matrix element; 2) the evolution equations for the gluon spin take very different forms in the Feynman and axial gauges, but yield the same leading beh...

This study investigated the performance and aeroelastic characteristics of a wind turbine blade based on strongly coupled approach (two-way fluid structure interaction) to simulate the transient FSI[1] responses of HAWT[2]. Aerodynamic response was obtained by 3D CFD-URANS approach and structural response was obtained by 3D Finite element method. ...

Abstract. In the present work, a consistent method for calculating lift and drag forces from 2-D airfoil data dihedral or coned horizontal-axis wind turbines when using generalized lifting-line methods is described. The refer to models that discretize blade radially into sections use data, example, (LL), actuator line (AL), element momentum (BEM) vortex cylinder (BEVC) methods. A interpretation...