An application of lubrication theory to predict useful flow-rate of coolants on grinding porous media

1997 ◽  
Vol 30 (8) ◽  
pp. 575-581 ◽  
Author(s):  
Chang Chong-Ching
1992 ◽  
Vol 114 (1) ◽  
pp. 61-66 ◽  
Author(s):  
F. Engineer ◽  
C. Guo ◽  
S. Malkin

An experimental test rig was developed to measure the amount of grinding fluid which flows through the grinding zone in straight plunge grinding. Proportional relationships were generally obtained between the flow rate from the nozzle and the useful flow rate of fluid passing through the grinding zone. The percentage of applied fluid passing through the grinding zone was found to depend mainly on the bulk porosity of the grinding wheel and the nozzle position. Wheel dressing has only a secondary influence, which is attributed to its influence on the surface porosity of the wheel. The workspeed and wheel depth of cut have virtually no influence.


1992 ◽  
Vol 114 (4) ◽  
pp. 427-434 ◽  
Author(s):  
C. Guo ◽  
S. Malkin

A theoretical model of fluid flow in grinding has been developed by an analysis of fluid flow through a porous medium. Fluid tangential velocity, radial velocity, depth of penetration into the wheel, and the useful flow rate through the grinding zone are predicted by using this model. The analysis indicates that the nozzle position, nozzle velocity (or flow rate), and the effective wheel porosity are the three main factors which most significantly influence the useful flow rate through the grinding zone. A dimensionless effective wheel porosity parameter is introduced which is the ratio of the effective wheel porosity to its bulk porosity. By fitting the theoretical analysis to available experimental results, creep feed wheels were found to have much bigger dimensionless effective porosities than conventional wheels, which enhances their ability to more effectively pump fluid through the grinding zone.


2015 ◽  
Vol 84 (9-12) ◽  
pp. 2113-2126 ◽  
Author(s):  
Yanbin Zhang ◽  
Changhe Li ◽  
Qiang Zhang ◽  
Dongzhou Jia ◽  
Sheng Wang ◽  
...  

2018 ◽  
Vol 8 (9) ◽  
pp. 1670 ◽  
Author(s):  
Wei Zhong ◽  
Xiang Ji ◽  
Chong Li ◽  
Jiwen Fang ◽  
Fanghua Liu

Sintered metal porous media are widely used in a broad range of industrial equipment. Generally, the flow properties in porous media are represented by an incompressible Darcy‒Forchheimer regime. This study uses a modified Forchheimer equation to represent the flow rate characteristics, which are then experimentally and theoretically investigated using a few samples of sintered metal porous media. The traditional steady-state method has a long testing time and considerable air consumption. With this in mind, a discharge method based on an isothermal chamber filled with copper wires is proposed to simultaneously determine the permeability and inertial coefficient. The flow rate discharged from the isothermal chamber is calculated by differentiating the measured pressure, and a paired dataset of pressure difference and flow rate is available. The theoretical representations of pressure difference versus flow rate show good agreement with the steady-state results. Finally, the volume limit of the isothermal chamber is addressed to ensure sufficient accuracy.


SPE Journal ◽  
2018 ◽  
Vol 24 (01) ◽  
pp. 01-20 ◽  
Author(s):  
Omid Mohammadzadeh ◽  
Shawn David Taylor ◽  
Dmitry Eskin ◽  
John Ratulowski

Summary One of the complex processes of permeability impairment in porous media, especially in the near-wellbore region, is asphaltene-induced formation damage. During production, asphaltene particles precipitate out of the bulk fluid phase because of pressure drop, which might result in permeability reduction caused by both deposition of asphaltene nanoparticles on porous-medium surfaces and clogging of pore throats by larger asphaltene agglomerates. Experimental data will be used to identify the parameters of an impairment model being developed. As part of a larger effort to identify key mechanisms of asphaltene deposition in porous media and develop a model for asphaltene impairment by pressure depletion, this paper focuses on a systematic design and execution of an experimental study of asphaltene-related permeability damage caused by live-oil depressurization along the length of a flow system. An experiment was performed using a custom-designed 60-ft slimtube-coil assembly packed with silica sands to a permeability of 55 md. The customized design included a number of pressure gauges at regular intervals along the coil length, which enabled real-time measurement of the fluid-pressure profile across the full length of the slimtube coil. The test was performed on a well-characterized recombined live oil from the Gulf of Mexico (GOM) that is a known problematic asphaltenic oil. Under a constant differential pressure, the injection flow rate of the live oil through the slimtube coil decreased over time as the porous medium became impaired. During the impairment stage, samples of the produced oil were collected on a regular basis for asphaltene-content measurement. After more than 1 month, the impairment test was terminated; the live oil was purged from the slimtube coil with helium at a pressure above the asphaltene-onset pressure (AOP); and the entire system was gently depressurized to bring the coil to atmospheric conditions while preserving the asphaltene-damaged zones of the coil. The permeability and porosity of the porous medium changed because of asphaltene impairment that was triggered by pressure depletion. Results indicated that the coil permeability was impaired by approximately 32% because of pressure depletion below the AOP, with most of the damage occurring in the latter section of the tube, which operated entirely below the AOP. Post-analytical studies indicated lower asphaltene content of the produced-oil samples compared with the injecting fluid. The distribution of asphaltene deposits along the length of the coil was determined by cutting the slimtube coil into 2- to 3-ft-long sections and using solvent extraction to collect the asphaltenes in each section. The extraction results confirmed that the observed permeability impairment was indeed caused by asphaltene deposition in the middle and latter sections of the coil, where the pressure was less than the AOP. With the success of this experiment, the same detailed analysis can be extended to a series of experiments to determine the effects of different key parameters on pressure-induced asphaltene impairment, including flow rate, wettability, and permeability.


2021 ◽  
pp. petgeo2020-062
Author(s):  
Jingtao Zhang ◽  
Haipeng Zhang ◽  
Donghee Lee ◽  
Sangjin Ryu ◽  
Seunghee Kim

Various energy recovery, storage, conversion, and environmental operations may involve repetitive fluid injection and, thus, cyclic drainage-imbibition processes. We conducted an experimental study for which polydimethylsiloxane (PDMS)-based micromodels were fabricated with three different levels of pore-space heterogeneity (coefficient of variation, where COV = 0, 0.25, and 0.5) to represent consolidated and/or partially consolidated sandstones. A total of ten injection-withdrawal cycles were applied to each micromodel at two different flow rates (0.01 and 0.1 mL/min). The experimental results were analyzed in terms of flow morphology, sweep efficiency, residual saturation, the connection of fluids, and the pressure gradient. The pattern of the invasion and displacement of nonwetting fluid converged more readily in the homogeneous model (COV = 0) as the repetitive drainage-imbibition process continued. The overall sweep efficiency converged between 0.4 and 0.6 at all tested flow rates, regardless of different flow rates and COV in this study. In contrast, the effective sweep efficiency was observed to increase with higher COV at the lower flow rate, while that trend became the opposite at the higher flow rate. Similarly, the residual saturation of the nonwetting fluid was largest at COV = 0 for the lower flow rate, but it was the opposite for the higher flow rate case. However, the Minkowski functionals for the boundary length and connectedness of the nonwetting fluid remained quite constant during repetitive fluid flow. Implications of the study results for porous media-compressed air energy storage (PM-CAES) are discussed as a complementary analysis at the end of this manuscript.Supplementary material: Figures S1 and S2 https://doi.org/10.6084/m9.figshare.c.5276814.Thematic collection: This article is part of the Energy Geoscience Series collection available at: https://www.lyellcollection.org/cc/energy-geoscience-series


2014 ◽  
Vol 136 (2) ◽  
Author(s):  
Jun Jie Liu ◽  
Hua Zhang ◽  
S. C. Yao ◽  
Yubai Li

Compared to single-phase heat transfer, two-phase microchannel heat sinks utilize latent heat to reduce the needed flow rate and to maintain a rather uniform temperature close to the boiling temperature. The challenge in the application of cooling for electronic chips is the necessity of modeling a large number of microchannels using large number of meshes and extensive computation time. In the present study, a modified porous media method modeling of two-phase flow in microchannels is performed. Compared with conjugate method, which considers individual channels and walls, it saves computation effort and provides a more convenient means to perform optimization of channel geometry. The porous media simulation is applied to a real chip. The channels of high heat load will have higher qualities, larger flow resistances, and lower flow rates. At a constant available pressure drop over the channels, the low heat load channels show much higher mass flow rates than needed. To avoid this flow maldistribution, the channel widths on a chip are adjusted to ensure that the exit qualities and mass flow rate of channels are more uniform. As a result, the total flow rate on the chip is drastically reduced, and the temperature gradient is also minimized. However, it only gives a relatively small reduction on the maximum surface temperature of chip.


2019 ◽  
Vol 21 (27) ◽  
pp. 14605-14611 ◽  
Author(s):  
R. Moosavi ◽  
A. Kumar ◽  
A. De Wit ◽  
M. Schröter

At low flow rates, the precipitate forming at the miscible interface between two reactive solutions guides the evolution of the flow field.


2011 ◽  
Vol 483 ◽  
pp. 320-326 ◽  
Author(s):  
Zhou Ling ◽  
Tao Yang ◽  
Fan Chao Meng ◽  
Lin Yi ◽  
Xiang Xian Zhang

Aiming at the coupling problems of electrical field and flow field in porous media microchannels, the mathematical model of electroosmotic(EO) flow is built. For a single microchannel, the influence of voltage on velocity and joule heat is analyzed by using CoventorWare. Numerical analysis shows that the velocity is proportional to the voltage and the joule heat is small and negligible. For the porous media, the flow rate is investigated by truncated Gaussian distribution of pore diameter. The electroosmotic microporous pump is fabricated, and the experimental results indicate that the maximum flow rate of porous media micropump is 16.89ml/min and the maximum pressure is 120.1kPa.


Sign in / Sign up

Export Citation Format

Share Document