scholarly journals Analytical Modeling and Contradictions in Limestone Reservoirs: Breccias, Vugs, and Fractures

2015 ◽  
Vol 2015 ◽  
pp. 1-28 ◽  
Author(s):  
Nelson Barros-Galvis ◽  
Pedro Villaseñor ◽  
Fernando Samaniego
Keyword(s):  
Fluid Flow ◽  
Field Data ◽  
Analytical Modeling ◽  
Fluid Velocity ◽  
Analytical Models ◽  
Diagnostic Tools ◽  
Dynamic Characterization ◽  
Hydrodynamic Behavior ◽  
Oil Flow ◽  
Analytic Models

Modeling of limestone reservoirs is traditionally developed applying tectonic fractures concepts or planar discontinuities and has been simulated dynamically without considering nonplanar discontinuities as sedimentary breccias, vugs, fault breccias, and impact breccias, assuming that all these nonplanar discontinuities are tectonic fractures, causing confusion and contradictions in reservoirs characterization. The differences in geometry and connectivity in each discontinuity affect fluid flow, generating the challenge to develop specific analytical models that describe quantitatively hydrodynamic behavior in breccias, vugs, and fractures, focusing on oil flow in limestone reservoirs. This paper demonstrates the differences between types of discontinuities that affect limestone reservoirs and recommends that all discontinuities should be included in simulation and static-dynamic characterization, because they impact fluid flow. To demonstrate these differences, different analytic models are developed. Findings of this work are based on observations of cores, outcrops, and tomography and are validated with field data. The explanations and mathematical modeling developed here could be used as diagnostic tools to predict fluid velocity and fluid flow in limestone reservoirs, improving the complex reservoirs static-dynamic characterization.

Oscillatory Compressional Behavior of Articular Cartilage and Its Associated Electromechanical Properties

1981 ◽  
Vol 103 (4) ◽  
pp. 280-292 ◽  
Author(s):  
R. C. Lee ◽  
E. H. Frank ◽  
A. J. Grodzinsky ◽  
D. K. Roylance
Keyword(s):  
Fluid Flow ◽  
Articular Cartilage ◽  
Molecular Mechanisms ◽  
Fluid Velocity ◽  
Streaming Potential ◽  
Usual Sense ◽  
Frequency Range ◽  
Confined Compression ◽  
Streaming Potentials ◽  
Compressive Stiffness

The compressive stiffness of articular cartilage was examined in oscillatory confined compression over a wide frequency range including high frequencies relevant to impact loading. Nonlinear behavior was found when the imposed sinusoidal compression amplitude exceeded a threshold value that depended on frequency. Linear behavior was attained only by suitable control of the compression amplitude. This was enabled by real time Fourier analysis of data which provided an accurate assessment of the extent of nonlinearity. For linear viscoelastic behavior, a stiffness could be defined in the usual sense. The dependence of the stiffness on ionic strength and proteoglycan content showed that electrostatic forces between matrix charge groups contribute significantly to cartilage’s compressive stiffness over the 0.001 to 20 Hz frequency range. Sinusoidal streaming potentials were also generated by oscillatory compression. A theory relating the streaming potential field to the fluid velocity field is derived and used to interpret the data. The observed magnitude of the streaming potential suggests that interstitial fluid flow is significant to cartilage behavior over the entire frequency range. The use of simultaneous streaming potential and stiffness data with an appropriate theory appears to be an important tool for assessing the relative contribution of fluid flow, intrinsic matrix viscoelasticity, or other molecular mechanisms to energy dissipation in cartilage. This method is applicable in general to hydrated, charged polymers.

Heat Transfer and Fluid Flow in Sintered Metallic Fiber Structures

2010 ◽  
Vol 638-642 ◽  
pp. 1884-1889 ◽  
Author(s):  
Olaf Andersen ◽  
Jens Meinert
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Heat Storage ◽  
Short Fiber ◽  
Analytical Models ◽  
Flow Properties ◽  
Metal Fiber ◽  
Open Cell ◽  
Sintered Metal ◽  
Inner Surface

Sintered metal fiber structures show a favourable ratio between pressure drop and inner surface area. Their exclusively open-cell morphology makes them well suited for heat transfer or temporary heat storage applications. Recently, highly conductive sintered metal fiber structures were successfully prepared from melt extracted aluminum alloy fibers. The heat conduction and fluid flow properties of metallic sintered short fiber structures were determined experimentally and compared with simple analytical models. It was found that equations taken from the available literature yield good approximations to the experimental results.

Mechanical Impact Effects of Fluid Hammer Effects on Drag Reduction of Coiled Tubing

2021 ◽  
pp. 1-10
Author(s):  
Yongsheng Liu ◽  
Xing Qin ◽  
Yuchen Sun ◽  
Zijun Dou ◽  
Jiansong Zhang ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Drag Reduction ◽  
Flow Rate ◽  
Fluid Velocity ◽  
Fluid Pressure ◽  
Great Influence ◽  
Radial Force ◽  
Fluid Flow Rate ◽  
Normal Contact ◽  
Coiled Tubing

Abstract Aiming at the oscillation drag reduction tool that improves the extension limit of coiled tubing downhole operations, the fluid hammer equation of the oscillation drag reducer is established based on the fluid hammer effect. The fluid hammer equation is solved by the asymptotic method, and the distribution of fluid pressure and flow velocity in coiled tubing with oscillation drag reducers is obtained. At the same time, the axial force and radial force of the coiled tubing caused by the fluid hammer oscillator are calculated according to the momentum theorem. The radial force will change the normal contact force of the coiled tubing which has a great influence on frictional drag. The results show that the fluid flow rate and pressure decrease stepwise from the oscillator position to the wellhead position, and the fluid flow rate and pressure will change abruptly during each valve opening and closing time. When the fluid passes through the oscillator, the unit mass fluid will generate an instantaneous axial tension due to the change in the fluid velocity, thereby converting the static friction into dynamic friction, which is conducive to the extend limit of coiled tubing.

Numerical analysis of time-dependent stagnation point flow of Oldroyd-B fluid subject to modified Fourier’s law

2021 ◽  
pp. 2150187
Author(s):  
Foukeea Qasim ◽  
Tian-Chuan Sun ◽  
S. Z. Abbas ◽  
W. A. Khan ◽  
M. Y. Malik
Keyword(s):  
Differential Equation ◽  
Fluid Flow ◽  
Stagnation Point ◽  
Numerical Solutions ◽  
Fluid Velocity ◽  
Nonlinear Partial Differential Equation ◽  
Thermal Relaxation ◽  
Stagnation Point Flow ◽  
Time Dependent ◽  
Parameter Values

This paper aims to investigate the time-dependent stagnation point flow of an Oldroyd-B fluid subjected to the modified Fourier law. The flow into a vertically stretched cylinder at the stagnation point is discussed. The heat flux model of a non-Fourier is intended for the transfer of thermal energy in fluid flow. The study is carried out on the surface heating source, namely the surface temperature. The developed nonlinear partial differential equation for regulating fluid flow and heat transport is transformed via appropriate similarity variables into a nonlinear ordinary differential equation. The development and analysis of convergent series solutions were considered for velocity and temperature. Prandtl number numerical values are computed and investigated. This study’s findings are compared to the previous findings. By making use of the bvp4c Matlab method, numerical solutions are obtained. Besides, high buoyancy parameter values are found to increase the fluid velocity for the stimulating approach. By improving the thermal relaxation time parameter values, heat transfer in the fluid flow decreases. The temperature field effects are displayed graphically.

IMPORTANCE OF 3D VEHICLE HEAT EXCHANGER MODELING

2021 ◽  
pp. 1-10
Author(s):  
Michal Schmid ◽  
Fatih Bozkurt ◽  
Petr Pašcenko ◽  
Pavel Petržela
Keyword(s):  
Fluid Flow ◽  
Heat Exchanger ◽  
Fluid Velocity ◽  
Coolant Temperature ◽  
Inlet Temperature ◽  
Vehicle Simulation ◽  
Velocity Magnitude ◽  
Primary Fluid ◽  
The Difference ◽  
Inlet Conditions

Abstract The work demonstrates, via a comprehensive study, the necessity of using a 3D CFD approach for heat exchanger (HTX) modelling within underhood vehicle simulation. The results are presented as the difference between 1D and 3D CFD approaches with a focus on auxiliary fluid (e.g. coolant) temperature prediction as a function of primary fluid (e.g. air) inlet conditions. It has been shown that the 1D approach could significantly underpredict auxiliary fluid inlet temperature due to neglecting the spatial distribution of primary fluid velocity magnitude. The resultant difference in the auxiliary fluid flow HTX inlet temperature is presented and discussed as a function of the Uniformity Index (UI) of the primary fluid flow velocity magnitude. Additionally, the 3D HTX model's importance is demonstrated in an industrial example of full 3D underhood simulation.

scholarly journals Study on the biomechanical responses of the loaded bone in macroscale and mesoscale by multiscale poroelastic FE analysis

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
WeiLun Yu ◽  
XiaoGang Wu ◽  
HaiPeng Cen ◽  
Yuan Guo ◽  
ChaoXin Li ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Fluid Velocity ◽  
Fluid Pressure ◽  
Biological Information ◽  
Von Mises Stress ◽  
Fe Model ◽  
Heterogeneous Distribution ◽  
Material Parameters ◽  
Mesoscopic Models ◽  
Von Mises

Abstract Background Bone is a hierarchically structured composite material, and different hierarchical levels exhibit diverse material properties and functions. The stress and strain distribution and fluid flow in bone play an important role in the realization of mechanotransduction and bone remodeling. Methods To investigate the mechanotransduction and fluid behaviors in loaded bone, a multiscale method was developed. Based on poroelastic theory, we established the theoretical and FE model of a segment bone to provide basis for researching more complex bone model. The COMSOL Multiphysics software was used to establish different scales of bone models, and the properties of mechanical and fluid behaviors in each scale were investigated. Results FE results correlated very well with analytical in macroscopic scale, and the results for the mesoscopic models were about less than 2% different compared to that in the macro–mesoscale models, verifying the correctness of the modeling. In macro–mesoscale, results demonstrated that variations in fluid pressure (FP), fluid velocity (FV), von Mises stress (VMS), and maximum principal strain (MPS) in the position of endosteum, periosteum, osteon, and interstitial bone and these variations can be considerable (up to 10, 8, 4 and 3.5 times difference in maximum FP, FV, VMS, and MPS between the highest and the lowest regions, respectively). With the changing of Young’s modulus (E) in each osteon lamella, the strain and stress concentration occurred in different positions and given rise to microscale spatial variations in the fluid pressure field. The heterogeneous distribution of lacunar–canalicular permeability (klcp) in each osteon lamella had various influence on the FP and FV, but had little effect on VMS and MPS. Conclusion Based on the idealized model presented in this article, the presence of endosteum and periosteum has an important influence on the fluid flow in bone. With the hypothetical parameter values in osteon lamellae, the bone material parameters have effect on the propagation of stress and fluid flow in bone. The model can also incorporate alternative material parameters obtained from different individuals. The suggested method is expected to provide dependable biological information for better understanding the bone mechanotransduction and signal transduction.

scholarly journals Analytical Modeling and Simulation of an Electromagnetic Energy Harvester for Pulsating Fluid Flow in Pipeline

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Sadia Bakhtiar ◽  
Farid Ullah Khan
Keyword(s):  
Fluid Flow ◽  
Modeling And Simulation ◽  
Analytical Modeling ◽  
Energy Harvester ◽  
Damping Ratio ◽  
Electromagnetic Energy ◽  
Pressure Amplitude ◽  
Load Voltage ◽  
Pulsating Fluid Flow ◽  
Pulsating Fluid

This paper presents the analytical modeling and simulation of an electromagnetic energy harvester (having linear behaviour) that generates power from pulsating fluid flow for pipeline condition monitoring systems. The modeled energy harvester is comprised of a cylindrical permanent magnet and a wound coil attached to a flexible membrane which oscillates due to the pulsating fluid flow in the pipe over which the prototype is considered to be mounted. In the harvester electrical energy is produced due to the relative motion between the coil and magnet. Based on the harvester’s architecture a lumped parameter model (single degree of freedom system) is developed and is simulated at different physical operational conditions. The simulation is performed at pressure amplitude of 625 Pa. When subjected to the operational frequency sweep, at the harvester’s resonant frequency (500 Hz) and damping ratio of 0.01, the devised model predicted the maximum open circuit voltage of 2.55 V and load voltage of 1.27 V. While operating under resonance, the maximum load voltage of 2.45 V is estimated at load resistance of 100 Ω. However, at an optimum load of 4.3 Ω, the simulation shows a production of 188151.2 μW power at a frequency of 500 Hz.

Motorcycle Analytical Modeling Including Tire–Wheel Nonuniformities for Ride Comfort Analysis

2017 ◽  
Vol 45 (2) ◽  
pp. 101-120 ◽  
Author(s):  
Matheus de B. Vallim ◽  
José M. C. Dos Santos ◽  
Argemiro L. A. Costa
Keyword(s):  
Degrees Of Freedom ◽  
Analytical Modeling ◽  
Ride Comfort ◽  
Experimental Tests ◽  
Rotational Frequency ◽  
Analytical Models ◽  
Vertical Force ◽  
Lumped Mass ◽  
Multi Body ◽  
4 Degrees Of Freedom

ABSTRACT The transmission of vibrations in motorcycles and their perception by the passengers are fundamental in comfort analysis. Tire nonuniformities can generate self-excitations at the rotational frequency of the wheel and contribute to the ride vibration environment. In this work a multi-body motorcycle model is built to evaluate the ride comfort with respect to tire nonuniformities. The aim is to obtain a multi–degrees-of-freedom dynamic model that includes both the contributions of the motorcycle and tire–wheel assembly structures. This representation allows the tire nonuniformities to predict the vertical force variations on the motorcycle and can be used through a root mean square acceleration evaluation for ride comfort analysis. The motorcycle model proposed is a 10-degrees-of-freedom system, where each tire–wheel is a 4-degrees-of-freedom model. The tire–wheel assemblies include two types of nonuniformities: lumped mass imbalance and radial run-out. Simulations of analytical models are compared with experimental tests.

Fluid Flow Characteristics of a Confined Slot Jet Without or With a Target Surface

2005 ◽  
Author(s):  
L. K. Liu ◽  
C. J. Fang ◽  
M. C. Wu ◽  
C. Y. Lee ◽  
Y. H. Hung
Keyword(s):  
Reynolds Number ◽  
Fluid Flow ◽  
Fluid Velocity ◽  
Flow Characteristics ◽  
Target Surface ◽  
Streamwise Velocity ◽  
Separation Distance ◽  
Experimental Investigations ◽  
Flow Parameters ◽  
Fluid Flow Characteristics

A series of experimental investigations with a stringent measurement method on the fluid flow characteristics of slot jet without or with a target surface have been successfully conducted. From all the fluid velocity data measured in the present study, the experimental conditions have been verified to be spanwise-symmetrically maintained and the results have been achieved in a spanwise-symmetric form. Three types of jet configuration without or with target surface are investigated: (A) Confined Slot Jet without Target Surfaces – the fluid flow parameters studied in the present investigation is the jet Reynolds number (ReD). Its ranges are ReD=506-1517. (B) Confined Slot Jet with Smooth Surfaces – the fluid flow parameters studied in the present investigation include the ratio of jet separation distance (H) to nozzle width (W) and the jet Reynolds number (ReD). The ranges of the relevant parameters are H/W=2–10 and ReD=504–1526. (C) Confined Slot Jet with Extended Surfaces – the fluid flow parameters studied include the ratio of jet separation distance (H) to nozzle width (W), the Reynolds number (ReD) and the ratio of extended surface height (Hes) to nozzle width (W). Their ranges are H/W=3–10, Hes/W=0.74-3.40 and ReD=501–1547. The flow characteristics such as the local mean streamwise velocity distribution, mean streamwise velocity decay along jet centerline, local jet turbulence intensity distribution, and turbulence intensities along jet centerline have been presented and discussed in the study.

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