scholarly journals Tumor Boundary Estimation Through Time-Domain Peaks Monitoring: Numerical Predictions and Experimental Results in Tissue-Mimicking Phantoms

2009 ◽  
Vol 56 (11) ◽  
pp. 2634-2641 ◽  
Author(s):  
Peng Wang ◽  
Christopher L. Brace ◽  
Mark C. Converse ◽  
John G. Webster
Keyword(s):  
Time Domain ◽  
Experimental Results ◽  
Numerical Predictions ◽  
Boundary Estimation

Advanced Fault Isolation Technique Using Electro-Optical Terahertz Pulse Reflectometry (EOTPR) for 2D and 2.5D Flip-Chip Package

2012 ◽  
Author(s):  
Lihong Cao ◽  
Manasa Venkata ◽  
Meng Yeow Tay ◽  
Wen Qiu ◽  
J. Alton ◽  
...  
Keyword(s):  
Time Domain ◽  
Flip Chip ◽  
Time Domain Reflectometry ◽  
Fault Isolation ◽  
Experimental Results ◽  
Terahertz Pulse ◽  
Isolation And Identification ◽  
Isolation Technique ◽  
Non Destructive

Abstract Electro-optical terahertz pulse reflectometry (EOTPR) was introduced last year to isolate faults in advanced IC packages. The EOTPR system provides 10μm accuracy that can be used to non-destructively localize a package-level failure. In this paper, an EOTPR system is used for non-destructive fault isolation and identification for both 2D and 2.5D with TSV structure of flip-chip packages. The experimental results demonstrate higher accuracy of the EOTPR system in determining the distance to defect compared to the traditional time-domain reflectometry (TDR) systems.

Numerical investigation of the propagation of shock waves in rigid porous materials: development of the computer code and comparison with experimental results

1996 ◽  
Vol 324 ◽  
pp. 163-179 ◽  
Author(s):  
A. Levy ◽  
G. Ben-Dor ◽  
S. Sorek
Keyword(s):  
Porous Materials ◽  
Initial Conditions ◽  
Computer Code ◽  
Experimental Results ◽  
Numerical Code ◽  
Materials Development ◽  
Numerical Predictions ◽  
Wide Range ◽  
Dimensional Version ◽  
The One

The governing equations of the flow field which is obtained when a thermoelastic rigid porous medium is struck head-one by a shock wave are developed using the multiphase approach. The one-dimensional version of these equations is solved numerically using a TVD-based numerical code. The numerical predictions are compared to experimental results and good to excellent agreements are obtained for different porous materials and a wide range of initial conditions.

Modal superposition in the time domain: Theory and experimental results

1995 ◽  
Vol 97 (1) ◽  
pp. 92-97 ◽  
Author(s):  
Marinus M. Boone ◽  
Gilles Janssen ◽  
Michiel van Overbeek
Keyword(s):  
Time Domain ◽  
Experimental Results ◽  
Domain Theory ◽  
Modal Superposition ◽  
The Time Domain

scholarly journals Harmonic Cancellation

2021 ◽  
Author(s):  
Alain de Cheveigné
Keyword(s):  
Auditory System ◽  
Time Domain ◽  
Experimental Results ◽  
Target Sound ◽  
Neural Representations ◽  
Behavioral Studies ◽  
System P ◽  
Harmonic Cancellation ◽  
The Time Domain

This paper reviews the hypothesis of {\em harmonic cancellation}\ according to which an interfering sound is suppressed or canceled on the basis of its harmonicity (or periodicity in the time domain). It defines the concept, discusses theoretical arguments in its favor, and reviews experimental results that support it, or not. If correct, the hypothesis likely draws on time domain processing of temporally-accurate neural representations within the brainstem, as required also by the classic Equalization-Cancellation (EC) model of binaural unmasking. It predicts that a target sound corrupted by interference will be easier to hear if the interference is harmonic than inharmonic, all else being equal. This prediction is borne out in a number of behavioral studies, but not all. The paper reviews those results, with the aim to understand the inconsistencies and come up with a reliable conclusion for, or against, the hypothesis of harmonic cancellation within the auditory system.

scholarly journals A Time Domain Passivity Control Scheme for Bilateral Teleoperation

Electronics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 325 ◽  
Author(s):  
Long Sheng ◽  
Usman Ahmad ◽  
Yongqiang Ye ◽  
Ya-Jun Pan
Keyword(s):  
Time Domain ◽  
Parametric Design ◽  
Switching Time ◽  
Experimental Results ◽  
Division Problem ◽  
Bilateral Teleoperation ◽  
Safe Operation ◽  
Guaranteed Stability ◽  
Control Scheme ◽  
And Control

Conventional time domain passivity control inevitably embodies division. Zero division can occur under a tiny force or velocity, which may be inevitable, and will be the cause of control crash. To avoid the zero division problem and control crash, we propose a switching dissipation controller for guaranteed stability. The parametric design of the proposed approach is discussed. The switching time domain passivity control is then applied to teleoperation and safe operation is achieved. Simulation and experimental results are demonstrated to validate the effectiveness of the proposed control scheme.

Numerical predictions of the flow characteristics of subsonic jet emanating from corrugated lobed nozzle

2020 ◽  
Vol 92 (7) ◽  
pp. 955-972
Author(s):  
Roy V. Paul ◽  
Kriparaj K.G. ◽  
Tide P.S.
Keyword(s):  
Flow Characteristics ◽  
Experimental Results ◽  
Potential Core ◽  
Content Type ◽  
Numerical Predictions ◽  
Core Length ◽  
Chevron Nozzle ◽  
Centreline Velocity ◽  
Subsonic Jet ◽  
Lobed Nozzle

Purpose The purpose of this study is to investigate the aerodynamic characteristics of subsonic jet emanating from corrugated lobed nozzle. Design/methodology/approach Numerical simulations of subsonic turbulent jets from corrugated lobed nozzles using shear stress transport k-ω turbulence model have been carried out. The analysis was carried out by varying parameters such as lobe length, lobe penetration and lobe count at a Mach number of 0.75. The numerical predictions of axial and radial variation of the mean axial velocity, u′u′ ¯ and v′v′ ¯ have been compared with experimental results of conventional round and chevron nozzles reported in the literature. Findings The centreline velocity at the exit of the corrugated lobed nozzle was found to be lower than the velocity at the outer edges of the nozzle. The predicted potential core length is lesser than the experimental results of the conventional round nozzle and hence the decay in centreline velocity is faster. The centreline velocity increases with the increase in lobe length and becomes more uniform at the exit. The potential core length increases with the increase in lobe count and decreases with the increase in lobe penetration. The turbulent kinetic energy region is narrower with early appearance of a stronger peak for higher lobe penetration. The centreline velocity degrades much faster in the corrugated nozzle than the chevron nozzle and the peak value of Reynolds stress appears in the vicinity of the nozzle exit. Practical implications The corrugated lobed nozzles are used for enhancing mixing without the thrust penalty inducing better acoustic benefits. Originality/value The prominent features of the corrugated lobed nozzle were obtained from the extensive study of variation of flow characteristics for different lobe parameters after making comparison with round and chevron nozzle, which paved the way to the utilization of these nozzles for various applications.

A Duct Optimization Study for a Vertical Axis Hydro-current Turbine Model

2011 ◽  
Vol 134 (2) ◽  
Author(s):  
M. Alidadi ◽  
V. Klaptocz ◽  
G. W. Rawlings ◽  
Y. Nabavi ◽  
S. Calisal
Keyword(s):  
Power Output ◽  
Numerical Optimization ◽  
Vertical Axis ◽  
Experimental Results ◽  
Maximum Power Output ◽  
Numerical Predictions ◽  
Optimization Study ◽  
Current Turbine ◽  
Turbine Model ◽  
Good Agreement

A numerical optimization study is used to design a duct for a model of vertical axis hydro-current turbine. The effects of this duct on the power output and torque fluctuations of the turbine model are then examined numerically and experimentally. Relatively good agreement was obtained between the experimental results and numerical predictions especially at higher tip speed ratios. Experimental results show an 85% increase in the maximum power output when the turbine is placed inside the duct. The numerical and experimental torque curves for the turbine also show substantial reductions in the torque fluctuations as a result of ducting.

Application of an Object-Oriented CFD Code to Heat Transfer Analysis

2008 ◽  
Author(s):  
Luca Mangani ◽  
A. Andreini
Keyword(s):  
Heat Transfer ◽  
Turbulence Models ◽  
Lateral Spreading ◽  
Impinging Jets ◽  
Experimental Results ◽  
Heat Transfer Analysis ◽  
Specific Class ◽  
Turbine Cooling ◽  
Numerical Predictions ◽  
High Flexibility

This paper is aimed at showing the performances obtained with an open-source CFD code for heat transfer predictions after the addiction of specific modules. The development steps to make this code suitable for such simulations are described in order to point out its potentiality as a customizable CFD tool, appropriate for both academic and industrial research. The C++ library, named OpenFOAM, offers specific class and polyhedral finite volume operators thought for continuum mechanics simulations as well as built-in solvers and utilities. To make it robust, fast and reliable for RANS heat transfer predictions it was indeed necessary to implement additional submodules. The package coded by the authors within the OpenFOAM environment includes a suitable algorithm for compressible steady-state analysis. A SIMPLE like algorithm was specifically developed to extend the operability field to a wider range of Mach numbers. A set of Low-Reynolds eddy-viscosity turbulence models, chosen amongst the best performing in wall bounded flows, were developed. In addition an algebraic anisotropic correction, to increase jets lateral spreading, and an automatic wall treatment, to obtain mesh independence, were added. The results presented cover several types of flows amongst the most typical for turbomachinery and combustor gas turbine cooling devices. Impinging jets were investigated as well as film and effusion cooling flows, both in single and multi-hole configuration. Numerical predictions for wall effectiveness and wall heat transfer coefficient were tested against standard literature and in-house set-up experimental results. The numerical predictions obtained proves to be in-line with the equivalent models of commercial CFD packages obtaining a general good agreement with the experimental results. Moreover during the tests OpenFOAM code has shown a good accuracy and robustness, as well as an high flexibility in the implementation of user-defined submodules.

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