نتایج جستجو برای: composite propeller

تعداد نتایج: 125326  

1997
J. Balla M. V. Polyakov C. Weiss

We compute the nucleon matrix elements of QCD operators of twist 3 and 4 in the instanton vacuum. We consider the operators determining 1/Q 2 –power corrections to the Bjorken, Ellis–Jaffe and Gross–Llewellyn-Smith sum rules. The nucleon is described as a soliton of the effective chiral theory derived from instantons in the 1/N c –expansion. QCD operators involving the gluon field are systemati...

2008
A. Sh. Amini M. Varshosaz M. Saadatseresht

This paper investigates the precision and capability of low cost off-line industrial photogrammetry for determination of deformations in aircraft parts. The study concentrates on deformation analysis of an airplane propeller through standard photogrammetric procedures. In this regard, around 100 targets were fixed on the blades of the propeller and imaged from several stations. The left and rig...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2007
Johanna Napetschnig Günter Blobel André Hoelz

The mammalian nuclear pore complex (NPC) is an approximately 120-MDa proteinaceous assembly consisting of approximately 30 proteins and is the sole gate in the nuclear envelope. The human protooncogene Nup214 was first identified as a target for chromosomal translocation involved in leukemogenesis. Nup214 is located on the cytoplasmic face of the NPC and is implicated in anchoring the cytoplasm...

2017
Hairuniza Ahmed Kutty Parvathy Rajendran

The current work presents the numerical prediction method to determine small-scale propeller performance. The study is implemented using the commercially available computational fluid dynamics (CFD) solver, FLUENT. Numerical results are compared with the available experimental data for an advanced precision composites (APC) Slow Flyer propeller blade to determine the discrepancy of the thrust c...

2009
Kaya Mori Malvin A. Ruderman

When an isolated magnetar with magnetic dipole field B ∼ 10 G moves at high velocity (v > 10 cm s) through the ISM, its transition into propeller effect driven spin-down may occur in less than 10 years. We propose that the nearby neutron star RXJ1856.5-3754 is such a magnetar, and has spun down by the propeller effect to a period greater than 10 sec within ∼ 5 × 10 years. This magnetar scenario...

Design and manufacturing of a high performance micro-hydro-kinetic turbine is discussed in the present paper. The main goal is manufacturing an equipped experimental model of hydro-kinetic turbine with highest energy absorption from water current. A multi-shape ducted turbine comprised of a multi-part diffuser was manufactured that can be converted to many experimental models for studying vario...

Surface-piercing propellers have been widely used in light and high-speed vessels because of their superior performance. One of the major steps in propeller selection algorithm is the determination of thrust as well as torque hydrodynamic coefficients. For the purpose of simplifying design and selection procedure, some relations are presented for determining hydrodynamic coefficients in some st...

2007
Luca Pivano Louis L. Whitcomb Tor Arne Johansen Thor Inge Fossen

In this paper a recently reported four-quadrant nonlinear thrust controller for marine propellers is applied to the velocity control of an underwater vehicle. The controller, designed for fixed pitch electrically driven propellers, is based on a shaft speed control and employs an estimate of the propeller torque loss. A simulation study is performed in order to compare the presented approach wi...

2015

Accuracy is the key issue in the precision forging. Geometric and dimension errors are the two significant defects found in most of near net or net shape manufacturing process. It becomes more critical for complex part such as an AUV propeller blade. In this study, geometric error was quantified by comparing the blade profile obtained from nominal geometry of the blade and the profile construct...

2016
William Craig Derrick Yeo Derek A. Paley

As small rotorcraft grow in capability, the possibilities for their application increase dramatically. Many of these new applications require stable outdoor flight, necessitating a closer look at the aerodynamic response of the aircraft in windy environments. This paper develops the equations of motion for a single-propeller test stand by analyzing the blade-flapping response of a small-stiff p...

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