Influence of fluid viscosity on the response of buried structures in earthquakes

Abstract “Hydroplaning characteristics” is one of the key functions for safe driving on wet roads. Since hydroplaning depends on vehicle velocity as well as the tire construction and tread pattern, a predictive simulation tool, which reflects all these effects, is required for effective and precise tire development. A numerical analysis procedure predicting the onset of hydroplaning of a tire, including the effect of vehicle velocity, is proposed in this paper. A commercial explicit-type FEM (finite element method)/FVM (finite volume method) package is used to solve the coupled problems of tire deformation and flow of the surrounding fluid. Tire deformations and fluid flows are solved, using FEM and FVM, respectively. To simulate transient phenomena effectively, vehicle-body-fixed reference-frame is used in the analysis. The proposed analysis can accommodate 1) complex geometry of the tread pattern and 2) rotational effect of tires, which are both important functions of hydroplaning simulation, and also 3) velocity dependency. In the present study, water is assumed to be compressible and also a laminar flow, indeed the fluid viscosity, is not included. To verify the effectiveness of the method, predicted hydroplaning velocities for four different simplified tread patterns are compared with experimental results measured at the proving ground. It is concluded that the proposed numerical method is effective for hydroplaning simulation. Numerical examples are also presented in which the present simulation methods are applied to newly developed prototype tires.

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An Infrared Microscope for Use on a Focused Ion Beam for Circuit Edit and Backside Edit Applications

ISTFA 2015: Conference Proceedings from the 41st International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2015p0097 ◽

2015 ◽

Author(s):

Alexander Richards ◽

Matthew Weschler ◽

Michael Durller

Keyword(s):

Focused Ion Beam ◽

Near Infrared ◽

Ion Beam ◽

Visible Spectrum ◽

Camera System ◽

Buried Structures ◽

Ir Camera ◽

Area Of Interest ◽

Near Ultraviolet ◽

Infrared Microscope

Abstract To help solve the navigational problem, i.e., being able to successfully locate a circuit for probing or editing without destroying chip functionality, a near-infrared (NIR), near-ultraviolet (NUV), and visible spectrum camera system was developed that attaches to most focused ion beam (FIB) or scanning electron microscope vacuum chambers. This paper reviews the details of the design and implementation of the NIR/NUV camera system, as instantiated upon the FEI FIB 200, with a particular focus on its use for the visualization of buried structures, and also for non-destructive real time area of interest location and end point detection. It specifically considers the use of the micro-optical camera system for its benefit in assisting with frontside and backside circuit edit, as well as other typical FIB milling activities. The quality of the image obtained by the IR camera rivals or exceeds traditional optical based imaging microscopy techniques.

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Influence of viscosity temperature dependence on the spectral characteristics of the thermoviscous liquids flow stability equation

Multiphase Systems ◽

10.21662/mfs2019.1.007 ◽

2019 ◽

Vol 14 (1) ◽

pp. 52-58 ◽

Cited By ~ 1

Author(s):

A.D. Nizamova ◽

V.N. Kireev ◽

S.F. Urmancheev

Keyword(s):

Reynolds Number ◽

Spectral Characteristics ◽

Wave Number ◽

Critical Parameters ◽

Fluid Viscosity ◽

Flat Channel ◽

Stability Equation ◽

The Stability ◽

Thermoviscous Fluid ◽

Sommerfeld Equation

The flow of a viscous model fluid in a flat channel with a non-uniform temperature field is considered. The problem of the stability of a thermoviscous fluid is solved on the basis of the derived generalized Orr-Sommerfeld equation by the spectral decomposition method in Chebyshev polynomials. The effect of taking into account the linear and exponential dependences of the fluid viscosity on temperature on the spectral characteristics of the hydrodynamic stability equation for an incompressible fluid in a flat channel with given different wall temperatures is investigated. Analytically obtained profiles of the flow rate of a thermovisible fluid. The spectral pictures of the eigenvalues of the generalized Orr-Sommerfeld equation are constructed. It is shown that the structure of the spectra largely depends on the properties of the liquid, which are determined by the viscosity functional dependence index. It has been established that for small values of the thermoviscosity parameter the spectrum compares the spectrum for isothermal fluid flow, however, as it increases, the number of eigenvalues and their density increase, that is, there are more points at which the problem has a nontrivial solution. The stability of the flow of a thermoviscous fluid depends on the presence of an eigenvalue with a positive imaginary part among the entire set of eigenvalues found with fixed Reynolds number and wavenumber parameters. It is shown that with a fixed Reynolds number and a wave number with an increase in the thermoviscosity parameter, the flow becomes unstable. The spectral characteristics determine the structure of the eigenfunctions and the critical parameters of the flow of a thermally viscous fluid. The eigenfunctions constructed in the subsequent works show the behavior of transverse-velocity perturbations, their possible growth or decay over time.

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Study on the Flow Characteristics of Shengli Oilfield Super Heavy Oil

The Open Fuels & Energy Science Journal ◽

10.2174/1876973x01710010069 ◽

2017 ◽

Vol 10 (1) ◽

pp. 69-78 ◽

Cited By ~ 1

Author(s):

Wang Shou-long ◽

Li Ai-fen ◽

Peng Rui-gang ◽

Yu Miao ◽

Fu Shuai-shi

Keyword(s):

Pressure Drop ◽

Pressure Gradient ◽

Heavy Oil ◽

Flow Characteristics ◽

Fluid Viscosity ◽

Linear Flow ◽

Start Up ◽

Non Linear ◽

Core Permeability ◽

Velocity Pressure

Objective:The rheological properties of oil severely affect the determination of percolation theory, development program, production technology and oil-gathering and transferring process, especially for super heavy oil reservoirs. This paper illustrated the basic seepage morphology of super heavy oil in micro pores based on its rheological characteristics.Methods:The non-linear flow law and start-up pressure gradient of super heavy oil under irreducible water saturation at different temperatures were performed with different permeable sand packs. Meanwhile, the empirical formulas between start-up pressure gradient, the parameters describing the velocity-pressure drop curve and the ratio of gas permeability of a core to fluid viscosity were established.Results:The results demonstrate that temperature and core permeability have significant effect on the non-linear flow characteristics of super heavy oil. The relationship between start-up pressure gradient of oil, the parameters representing the velocity-pressure drop curve and the ratio of core permeability to fluid viscosity could be described as a power function.Conclusion:Above all, the quantitative description of the seepage law of super heavy oil reservoir was proposed in this paper, and finally the empirical diagram for determining the minimum and maximum start-up pressure of heavy oil with different viscosity in different permeable formations was obtained.

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Influence of Eccentricity and Angular Velocity on Force Effects on Rotor of Magnetorheological Damper

EPJ Web of Conferences ◽

10.1051/epjconf/201818002091 ◽

2018 ◽

Vol 180 ◽

pp. 02091

Author(s):

Dominik Šedivý ◽

Petr Ferfecki ◽

Simona Fialová

Keyword(s):

Magnetic Induction ◽

Magnetorheological Damper ◽

Squeeze Film ◽

Fluid Viscosity ◽

Squeeze Film Damper ◽

Viscous Forces ◽

Angular Velocities ◽

Volume Method ◽

Gap Width ◽

Made In

This article presents the evaluation of force effects on squeeze film damper rotor. The rotor is placed eccentrically and its motion is translate-circular. The amplitude of rotor motion is smaller than its initial eccentricity. The force effects are calculated from pressure and viscous forces which were measured by using computational modeling. Damper was filled with magnetorheological fluid. Viscosity of this non-Newtonian fluid is given using Bingham rheology model. Yield stress is not constant and it is a function of magnetic induction which is described by many variables. The most important variables of magnetic induction are electric current and gap width between rotor and stator. The simulations were made in finite volume method based solver. The motion of the inner ring of squeeze film damper was carried out by dynamic mesh. Numerical solution was solved for five different initial eccentricities and angular velocities of rotor motion.

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Experiments and mechanistic modeling of viscosity effect on a multistage ESP performance under viscous fluid flow

Proceedings of the Institution of Mechanical Engineers Part A Journal of Power and Energy ◽

10.1177/09576509211014974 ◽

2021 ◽

pp. 095765092110149

Author(s):

Yi Shi ◽

Jianjun Zhu ◽

Haoyu Wang ◽

Haiwen Zhu ◽

Jiecheng Zhang ◽

...

Keyword(s):

Fluid Flow ◽

Viscous Fluid ◽

Prediction Error ◽

Flow Direction ◽

Fluid Viscosity ◽

Oil Viscosity ◽

Viscous Fluid Flow ◽

Viscosity Effect ◽

High Production Rate ◽

Pump Head

Assembled in series with multistage, Electrical Submersible Pumps (ESP) are widely used in offshore petroleum production due to the high production rate and efficiency. The hydraulic performance of ESPs is subjected to the fluid viscosity. High oil viscosity leads to the degradation of ESP boosting pressure compared to the catalog curves under water flow. In this paper, the influence of fluid viscosity on the performance of a 14-stage radial-type ESP under varying operational conditions, e.g. rotational speeds 1800–3500 r/min, viscosities 25–520 cP, was investigated. Numerical simulations were conducted on the same ESP model using a commercial Computational Fluid Dynamics (CFD) software. The simulated average pump head is comparable to the corresponding experimental data under different viscosities and rotational speeds with less than ±20% prediction error. A mechanistic model accounting for the viscosity effect on ESP boosting pressure is proposed based on the Euler head in a centrifugal pump. A conceptual best-match flowrate QBM is introduced, at which the impeller outlet flow direction matches the designed flow direction. The recirculation losses caused by the mismatch of velocity triangles and other head losses resulted from the flow direction change, friction loss and leakage flow etc., are included in the model. The comparison of model predicted pump head versus experimental measurements under viscous fluid flow conditions demonstrates good agreement. The overall prediction error is less than ±10%.

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Fluid–Structure Coupling Effects in a Dual U-Tube Coriolis Mass Flow Meter

Sensors ◽

10.3390/s21030982 ◽

2021 ◽

Vol 21 (3) ◽

pp. 982

Author(s):

Yuh-Chung Hu ◽

Zen-Yu Chen ◽

Pei-Zen Chang

Keyword(s):

Product Design ◽

Dynamic Balance ◽

Fluid Viscosity ◽

Fluid Structure ◽

Development Platform ◽

Design Considerations ◽

Manufacture Process ◽

Coupling Dynamics ◽

Comsol Simulation ◽

Important Design

Coriolis mass flowmeters are highly customized products involving high-degree fluid-structure coupling dynamics and high-precision manufacture. The typical delay from from order to shipment is at least 4 months. This paper presents some important design considerations through simulation and experiments, so as to provide manufacturers with a more time-efficient product design and manufacture process. This paper aims at simulating the fluid-structure coupling dynamics of a dual U-tube Coriolis mass flowmeter through the COMSOL simulation package. The simulation results are experimentally validated using a dual U-tube CMF manufactured by Yokogawa Co., Ltd. in a TAF certified flow testing factory provided by FineTek Co., Ltd. Some important design considerations are drawn from simulation and experiment. The zero drift will occur when the dual U-tube structure is unbalanced and therefore the dynamic balance is very important in the manufacturing of dual U-tube CMF. The fluid viscosity can be determined from the driving current of the voice coil actuator or the pressure loss between the inlet and outlet of CMF. Finally, the authors develop a simulation application based on COMSOL’s development platform. Users can quickly evaluate their design through by using this application. The present application can significantly shorten product design and manufacturing time.

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Monte Albán's Hidden Past: Buried Buildings and Sociopolitical Transformation

Latin American Antiquity ◽

10.1017/laq.2020.75 ◽

2020 ◽

pp. 1-23

Author(s):

Marc N. Levine ◽

Scott W. Hammerstedt ◽

Amanda Regnier ◽

Alex E. Badillo

Keyword(s):

Ground Penetrating Radar ◽

Electrical Resistance ◽

Early History ◽

Buried Structures ◽

Systematic Survey ◽

Monte Alban ◽

Ground Penetrating ◽

Shed Light

In this article, we present the most significant results of the Monte Albán Geophysical Archaeology Project. Using ground-penetrating radar, gradiometry, and electrical resistance, we carried out a systematic survey of the site's Main Plaza to identify buried prehispanic features that might shed light on Monte Albán's early history. The most important discoveries include three buried structures dating between the Danibaan (500–300 BC) and Nisa phases (100 BC–AD 100). We argue that the largest structure, measuring 18 × 18 m, was probably a temple platform and that all three of the structures were razed and buried by the end of the Nisa phase at the latest. Furthermore, we contend that these events were part of a major renovation and expansion of the site's Main Plaza that occurred during a pivotal period of dramatic sociopolitical transformation in the Zapotec capital.

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