The unsteady wake of an EPPLER 361 airfoil in pitching motion has been investigated in a subsonic wind tunnel by hot-wire anemometry. The airfoil was given the pitching motion about the one-quarter chord axis at reduced frequency of 0182. Streamwise mean velocity profiles (wake profiles) were investigated at several vertically aligned points behind the airfoil at one-quarter chord downstream di...

Abstract This paper presents the results of an experimental performance study electrically driven propeller in thrust and power recuperation mode a subsonic wind tunnel. Using reverberation chamber method, acoustic measurements were performed to evaluate them as reference relation data obtained. The three approaches investigated: Fixed pitch at speed reduction (case 1), controllable with negati...

Nowadays, wind energy is one of the most cost-effective and environmentally friendly energies in high demand due to shortages fossil fuels necessity reduce global carbon footprint. One main goals turbine development increase power output either by increasing blade swept area or velocity wind. In this article, a proprietary augmentation system was introduced vertical axis turbines (VAWT) free st...

The paper focuses on the loads applied to helicopter blade cross-sections in multibody dynamics system. main objective is simplify aerodynamics calculation and avoid time-consuming CFD methods. For this reason, way of computing proposed by using methods with a linear-elastic model. As primary tool for further research, MCS Adams software package selected. Splitting rotor into finite number sect...

In this study the augmentation of heat transfer in a rectangular channel with triangular vortex generators is evaluated. The span wise averaged Nusselt number, mean temperature and total heat flux are compared with and without vortex generators in the channel at a blade angle of 30° for Reynolds numbers 800, 1200, 1600, and 2000. The use of vortex generators increases the span wise averaged Nus...

Abstract The angle of attack and side-slip are two important flight parameters that directly affect the safety civil aircraft. This paper studies estimation method for according to air-data system, inertial navigation aircraft aerodynamic data improve under condition icing, failures, improper maintenance. Flight tests show proposed is feasible, reliable, has better accuracy. Furthermore, test a...

The purpose of this paper is to present the development of a simple turbulence representation suitable for helicopter dynamic simulation, stability and performance analysis, as well as pilot-in-the-loop rotorcraft handling qualities assessment. The frozen field hypothesis and linear approximation are assumed. Components of the uniform field velocity are included as additive perturbations affect...

Since the clinical introduction of proximal femoral nail antirotation (PFNA) by AO group in 2004 and PFNA-II (Asian version) in 2008, this type of cephalomedullary nail with single head-neck helical blade were commonly used in unstable pertrochanteric and intertrochanteric fractures in geriatric patients. Recently, severe complications of helical blade perforation through the femoral head, into...

BACKGROUND We describe two cases of recurrent acute angle-closure attack in patients with plateau iris syndrome after cataract extraction. Argon laser peripheral iridoplasty and cataract extraction have been used to reduce the occurrence of acute angle-closure attack in plateau iris syndrome although the risk cannot be completely eliminated. There is no consensus on the long term management of ...