Development and Characterization of Jet-Injected Vee-Gutter

ABSTRACTThe vee-gutter, which was conventionally used in a combustor for flame holding, was re-designed by employing the unsteady Coanda effect to inject fluids periodically into near wake of the vee-gutter. Fluidic targets were developed to induce self-sustained transverse oscillation of slit-jet. The self-sustained oscillating jet was conducted through passages and injected into the near wake of the vee-gutter. The behaviors and frequency characteristics of the slit-jet in the oscillation cavity and the turbulence properties in the wake were studied experimentally in a wind-tunnel by using the smoke-wire flow visualization technique and the hot-wire anemometer. The oscillation frequencies of the presently developed jet-injection vee-gutter were about 25 to 40 times higher than that of the conventionally used fluidic flowmeter. By estimating the Lagrangian integral time scale and employing the Taylor's frozen flow hypothesis, the integral length scales of turbulence fluctuations were calculated. The results showed that the integral length scales of turbulences of the jet-injected vee-gutter were significantly smaller than their counter parts of the conventional vee-gutter, which indicated the effects of vortex stretching induced by the periodic jet injection. The modifications of turbulence properties were presented and discussed.

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Detection of Ischemic Episodes Based on Two Consecutive Declines in the JT/ST Algebraic Relationship

Applied Sciences ◽

10.3390/app11114805 ◽

2021 ◽

Vol 11 (11) ◽

pp. 4805

Author(s):

Vaiva Šiaučiūnaitė ◽

Alfonsas Vainoras ◽

Zenonas Navickas ◽

Minvydas Ragulskis

Keyword(s):

Cardiovascular System ◽

Individual Performance ◽

The Self ◽

Self Organization ◽

Visualization Technique ◽

Dynamical Processes ◽

Recovery Processes ◽

Human Cardiovascular System

The main objective of this paper is to explore if the JT/ST algebraic relationship could be helpful for the identification of ischemic changes in the human cardiovascular system. The suggested visualization technique highlights the specifics of complex dynamical processes in the self-organization of the heart system during the load and recovery processes. It is demonstrated that the nonlinear algebraic relationship between the duration of the JT interval and the ST amplitude can be beneficial for a deeper interpretation of dynamical processes in the human cardiovascular system. The JT/ST relationship is used for the identification of the ischemic changes and for the characterization of individual performance of the person during the load and recovery processes.

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GROWTH AND CHARACTERIZATION OF ATOMIC AND NANOMETER SCALE WIRES ON THE SILICON SURFACE

Surface Review and Letters ◽

10.1142/s0218625x00000579 ◽

2000 ◽

Vol 07 (05n06) ◽

pp. 555-560 ◽

Cited By ~ 7

Author(s):

J. NOGAMI

Keyword(s):

Transport Properties ◽

Electronic Properties ◽

Self Assembly ◽

Silicon Surface ◽

Growth Behavior ◽

The Self ◽

Nanometer Scale ◽

Semiconductor Surfaces ◽

Length Scales

Growth of metals on semiconductor surfaces can result in the self-assembly of a variety of 1D or 2D structures whose lateral dimensions range from one atom to tens of atoms. Over this range in length scales, STM gives information about the structure, the growth behavior and the electronic properties of these small structures. STM and STS data on several different systems are presented. In addition, ongoing and future efforts to measure the transport properties of these small structures are described.

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Rapid Distortion of Homogeneous Turbulence Between Cylinders

Fluids Engineering ◽

10.1115/imece2004-60125 ◽

2004 ◽

Author(s):

Babak Emami ◽

Rui Liu ◽

David S.-K. Ting ◽

M. David Checkel

Keyword(s):

Wind Tunnel ◽

Turbulent Flow ◽

Closed Loop ◽

Perforated Plate ◽

Energy Dissipation Rate ◽

Hot Wire ◽

Mean Velocity ◽

Length Scales ◽

Turbulence Decay ◽

The Mean

The effects of ‘half-full-half’ cylinders on the distortion of a turbulent flow are experimentally investigated. A single hot-wire anemometry unit is used to measure the stream-wise parameters of the flow. The cylinders are 15.2 cm (6 in) in diameter and 76.2 cm (30 in) in height installed in a closed loop wind tunnel with a 76.2 cm by 76.2 cm (30 in by 30 in) cross section. Turbulent flow with a nominal mean velocity of 7.6 m/s was generated by means of a perforated plate situated at the entrance of the wind tunnel. It was found that the mean velocity increases significantly as the flow passes through the contracting passage created by the cylinders, whereas the rms turbulence intensity decreases about 12% but shows an increase of up to 14% very close to the full cylinder. As the flow was distorted, the Kolmogorov length scales were elongated in the stream-wise direction, resulting in a decrease in the rate of turbulence decay which appears as a decrease in energy dissipation rate. The stream-wise integral length scales also increased due to the elongation of eddies in the stream-wise direction. Also, analysis of the turbulence fluctuating velocity in the frequency domain showed a redistribution of stream-wise turbulence kinetic energy from large to small scales during the distortion.

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Characterization of plenum spectra in an arcjet wind tunnel

Journal of Thermophysics and Heat Transfer ◽

10.2514/3.902 ◽

1997 ◽

Vol 11 ◽

pp. 339-345

Author(s):

James P. Sawyer ◽

S. Rao ◽

Mohammad A. Rob ◽

Larry H. Mack ◽

Sivaram Arepalli ◽

...

Keyword(s):

Wind Tunnel

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Generation and Characterization of High Enthalpy CO2 Flow by Laser Driven Plasma Wind Tunnel

51st AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition ◽

10.2514/6.2013-193 ◽

2013 ◽

Author(s):

Makoto Matsui ◽

Shingo Yoneda ◽

Satoshi Nomura ◽

Yoshiki Yamagiwa ◽

Kimiya Komurasaki ◽

...

Keyword(s):

Wind Tunnel ◽

High Enthalpy ◽

Co2 Flow

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Characterization of wind-induced pressure on membrane roofs based on full-scale wind tunnel testing

Engineering Structures ◽

10.1016/j.engstruct.2021.112101 ◽

2021 ◽

Vol 235 ◽

pp. 112101

Author(s):

Johnny Estephan ◽

Changda Feng ◽

Arindam Gan Chowdhury ◽

Mauricio Chavez ◽

Appupillai Baskaran ◽

...

Keyword(s):

Wind Tunnel ◽

Full Scale ◽

Wind Tunnel Testing ◽

Tunnel Testing

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Characterization of Undoped, N- and P-Type Hydrogenated Nanocrystalline Silicon Carbide Films Deposited by Hot-Wire Chemical Vapor Deposition at Low Temperatures

Japanese Journal of Applied Physics ◽

10.1143/jjap.46.1415 ◽

2007 ◽

Vol 46 (4A) ◽

pp. 1415-1426 ◽

Cited By ~ 46

Author(s):

Shinsuke Miyajima ◽

Akira Yamada ◽

Makoto Konagai

Keyword(s):

Silicon Carbide ◽

Chemical Vapor Deposition ◽

Vapor Deposition ◽

Low Temperatures ◽

Chemical Vapor ◽

Nanocrystalline Silicon ◽

Hot Wire ◽

Nanocrystalline Silicon Carbide ◽

P Type

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Estimating the shape and size of supramolecular assemblies by variable temperature diffusion ordered spectroscopy

Organic & Biomolecular Chemistry ◽

10.1039/c4ob01373e ◽

2014 ◽

Vol 12 (40) ◽

pp. 7932-7936 ◽

Cited By ~ 23

Author(s):

Benjamin M. Schulze ◽

Davita L. Watkins ◽

Jing Zhang ◽

Ion Ghiviriga ◽

Ronald K. Castellano

Keyword(s):

Self Assembly ◽

Variable Temperature ◽

Supramolecular Assemblies ◽

The Self ◽

Conjugated Oligomers ◽

Photovoltaic Devices ◽

Temperature Diffusion ◽

Shape And Size

Reported is characterization of the self-assembly of π-conjugated oligomers, molecules studied recently in photovoltaic devices, using variable temperature diffusion ordered spectroscopy; the approach has allowed estimation of assembly size, shape, and molecularity.

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Study of the Laminar Free-Convection Wake Above an Isothermal Vertical Plate

Journal of Heat Transfer ◽

10.1115/1.3450054 ◽

1973 ◽

Vol 95 (3) ◽

pp. 289-294 ◽

Cited By ~ 14

Author(s):

N. E. Hardwick ◽

E. K. Levy

Keyword(s):

Free Convection ◽

Vertical Plate ◽

Fluid Motion ◽

Heated Plate ◽

Two Dimensional ◽

Wake Region ◽

Hot Wire ◽

Near Wake ◽

Steady Laminar ◽

Finite Difference Techniques

The steady, laminar, two-dimensional wake above a thin vertical isothermal heated plate cooled by free convection was investigated theoretically and experimentally. The system of partial differential equations governing the fluid motion and heat transfer in the vicinity of the plate and in the near wake region was formulated and solved using finite difference techniques. Using air, the temperature and velocity profiles in the wake region were measured experimentally using a laser holographic interferometer and a constant temperature hot wire anemometer.

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