Microwave signal emission in spin-torque vortex oscillators in metallic nanowires: Experimental measurements and micromagnetic numerical study

2012 ◽  
Vol 86 (6) ◽  
Author(s):  
F. Abreu Araujo ◽  
M. Darques ◽  
K. A. Zvezdin ◽  
A. V. Khvalkovskiy ◽  
N. Locatelli ◽  
...  
2007 ◽  
Vol 32 (12) ◽  
pp. 1647 ◽  
Author(s):  
C. G. Poulton ◽  
M. A. Schmidt ◽  
G. J. Pearce ◽  
G. Kakarantzas ◽  
P. St.J. Russell

Author(s):  
R. V. Chima ◽  
E. R. McFarland ◽  
J. R. Wood ◽  
J. Lepicovsky

The transonic flutter cascade facility at NASA Glenn Research Center was redesigned based on a combined program of experimental measurements and numerical analyses. The objectives of the redesign were to improve the periodicity of the cascade in steady operation, and to better quantify the inlet and exit flow conditions needed for CFD predictions. Part I of this paper describes the experimental measurements, which included static pressure measurements on the blade and endwalls made using both static taps and pressure sensitive paints, cobra probe measurements of the endwall boundary layers and blade wakes, and shadowgraphs of the wave structure. Part II of this paper describes three CFD codes used to analyze the facility, including a multibody panel code, a quasi-three-dimensional viscous code, and a fully three-dimensional viscous code. The measurements and analyses both showed that the operation of the cascade was heavily dependent on the configuration of the sidewalls. Four configurations of the sidewalls were studied and the results are described. For the final configuration, the quasi-three-dimensional viscous code was used to predict the location of mid-passage streamlines for a perfectly periodic cascade. By arranging the tunnel sidewalls to approximate these streamlines, side-wall interference was minimized and excellent periodicity was obtained.


2020 ◽  
Vol 31 (34) ◽  
pp. 345709
Author(s):  
X Yuan ◽  
Z Lu ◽  
S Li ◽  
S Fan ◽  
G Wang ◽  
...  

2016 ◽  
Vol 366 ◽  
pp. 88-96
Author(s):  
Raquel da Cunha Ribeiro da Silva ◽  
Carlos Salinas Sedano ◽  
Kamal A.R. Ismail ◽  
Paúl Adrian Delgado Maldonado

An experimental study was reported earlier on the development of frost formation by humid flow passing over the cylinder. In this study, dimensionless correlations used in previous experimental data, and reported empirical correlations of the Nusselt number, were used. This paper reports results of an experimental and numerical investigation where the emphasis was placed on obtaining empirical correlation for the Nusselt number. In this work some experimental results of the frost thickness around every cylinder in a triangular arrangement are presented, an estimated experimental correlation to find Nusselt number. This correlation is based on the experimental measurements in a wind tunnel situated in the Laboratory of Thermal storage and Fluids in the Mechanical Engineering Faculty at Unicamp. A numerical study is performed to study the frost formation in the cylindrical system.


1996 ◽  
Vol 463 ◽  
Author(s):  
A. A. Rodriguez ◽  
J. Valbuena

ABSTRACTThe ac and dc electrical properties of composite materials are studied using hierarchical lattices. First we show that the hierarchical model can correctly account for the main scaling properties of critical percolative structures. Then we study the effect of potential disorder by assuming that the microscopic conductances are distributed according to a power law distribution function. We find that in the limit of strong disorder, the predictions are in qualitative agreement with reported experimental measurements.


2016 ◽  
Vol 109 (22) ◽  
pp. 222403 ◽  
Author(s):  
P. Dürrenfeld ◽  
F. Gerhard ◽  
S. M. Mohseni ◽  
M. Ranjbar ◽  
S. R. Sani ◽  
...  

1997 ◽  
Vol 119 (4) ◽  
pp. 603-608 ◽  
Author(s):  
Y. C. Qu ◽  
L. Cheng ◽  
D. Rancourt

This paper presents an experimental assessment of the Tip Excitation Technique (TET) introduced in a companion paper. The aim of the technique is to measure the rotational compliance of attached plane structures. Following the guidelines established on the basis of a numerical study in the companion paper, experimental measurements were performed on a rectangular plate and results were compared with numerical simulations. The investigation focuses on the general performance of the technique, on the different types of excitation used and on other factors necessary to ensure accurate results. In addition, an error analysis is conducted to demonstrate the sensitivity of the results to biased measurement quantities. It is concluded that the proposed technique can be used in the low to middle frequency range, where relatively strong modal behavior is involved.


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