The Experts below are selected from a list of 222 Experts worldwide ranked by ideXlab platform
Phadungsak Rattanadecho - One of the best experts on this subject based on the ideXlab platform.
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Numerical analysis of heat-mass transport and Pressure Buildup of unsaturated porous medium in a rectangular waveguide subjected to a combined microwave and vacuum system
International Journal of Heat and Mass Transfer, 2013Co-Authors: Khomgris Chaiyo, Phadungsak RattanadechoAbstract:Abstract This paper presents two-dimensional numerical analysis of heat-mass transport and Pressure Buildup inside an unsaturated porous packed bed which is filled in a rectangular waveguide and subjected to a combined microwave and vacuum system. A microwave system supplies a monochromatic wave in a fundamental TE 10 mode. The unsaturated porous media is composed of glass beads, water and air. The finite difference time domain method is used to determine the electromagnetic field distribution in the rectangular waveguide by solving the transient Maxwell’s equations. The finite difference method together with Newton–Rephson technique is employed to predict the heat, multiphase flow and Pressure Buildup. The influences of vacuum Pressure and operating microwave frequency on temperature, microwave power absorbed, saturation and Pressure Buildup distribution, and movement of fluid inside the unsaturated porous media are investigated during microwave vacuum drying process.
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Analysis of Heat–Mass Transport and Pressure Buildup Induced inside Unsaturated Porous Media Subjected to Microwave Energy Using a Single (TE10) Mode Cavity
Drying Technology, 2011Co-Authors: Nattawut Suwannapum, Phadungsak RattanadechoAbstract:This article presents the two-dimensional numerical analysis of heat and mass transport and Pressure built up inside an unsaturated porous packed bed under microwave energy at a frequency of 2.45 GHz using a rectangular waveguide (TE10 mode). The unsaturated porous packed beds were composed by glass beads, water, and air. The samples were prepared by compacting uniformly with various thicknesses δ = 30, 50, and 80 mm and particle sizes d = 0.15 mm (fine packed bed) and 0.4 mm (coarse packed bed), respectively. A proposed model used to investigate heat–mass transport and Pressure Buildup phenomena inside the porous packed bed in which the rectangular waveguide with varying glass bead sizes and sample thicknesses was inserted. The results show that the effect of particle sizes and thicknesses of porous packed bed are primary factors determining heat and mass transport with multiphase flow. These findings can explain the phenomena taking place inside unsaturated porous media in a microwave drying process usi...
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analysis of heat mass transport and Pressure Buildup induced inside unsaturated porous media subjected to microwave energy using a single te10 mode cavity
Drying Technology, 2011Co-Authors: Nattawut Suwannapum, Phadungsak RattanadechoAbstract:This article presents the two-dimensional numerical analysis of heat and mass transport and Pressure built up inside an unsaturated porous packed bed under microwave energy at a frequency of 2.45 GHz using a rectangular waveguide (TE10 mode). The unsaturated porous packed beds were composed by glass beads, water, and air. The samples were prepared by compacting uniformly with various thicknesses δ = 30, 50, and 80 mm and particle sizes d = 0.15 mm (fine packed bed) and 0.4 mm (coarse packed bed), respectively. A proposed model used to investigate heat–mass transport and Pressure Buildup phenomena inside the porous packed bed in which the rectangular waveguide with varying glass bead sizes and sample thicknesses was inserted. The results show that the effect of particle sizes and thicknesses of porous packed bed are primary factors determining heat and mass transport with multiphase flow. These findings can explain the phenomena taking place inside unsaturated porous media in a microwave drying process usi...
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Analysis of Multiphase Flow and Heat Transfer: Pressure Buildup in an Unsaturated Porous Slab Exposed to Hot Gas
Drying Technology, 2007Co-Authors: Phadungsak Rattanadecho, Watit Pakdee, J. StakulcharoenAbstract:This study develops a mathematical model for coupled heat and mass transfer in an unsaturated porous slab exposed to a flowing hot gas. Effects of the initial saturation conditions on associated variables, i.e., total Pressure, temperature, moisture content, and multiphase flow, are studied. The Newton-Raphson method based on a finite volume technique is applied. This study emphasizes the influence of initial saturation level and gravitational effect in heat and multiphase flow phenomena associated with this system. Gravity enhances the downward flow of liquid within the porous slab. Pressure Buildup occurs near the interface between the wet and the dry zone. However, it appears that the order of magnitude to the total Pressure is small. This study explains the fundamental mechanism of multiphase flow that involves heat and mass transfer in a heated unsaturated porous slab.
Stefan Finstele - One of the best experts on this subject based on the ideXlab platform.
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Water-Steel Canister Interaction and H2 Gas Pressure Buildup in a Nuclear Waste Repository
Lawrence Berkeley National Laboratory, 2008Co-Authors: Rainer Senger, Stefan FinsteleAbstract:Corrosion of steel canisters, stored in a repository for spent fuel and high-level waste, leads to hydrogen gas generation in the backfilled emplacement tunnels, which may significantly affect long-term repository safety. Previous modeling studies used a constant H2 generation rate. However, iron corrosion and H2 generation rates vary with time, depending on factors such as water chemistry, water availability, and water contact area. To account for these factors and feedback mechanisms, we developed a chemistry model related to iron corrosion, coupled with two-phase (liquid and gas) flow phenomena that are driven by gas Pressure Buildup and water consumption. Results indicate that if H2 generation rates are dynamically calculated based on a chemistry model, the degree and extent of gas Pressure Buildup are much smaller compared to a simulation in which the coupling between flow and reactive transport mechansism is neglected.
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Water-Steel Canister Interaction and H2 Gas Pressure Buildup in aNuclear Waste Repository
2007Co-Authors: Rainer Senger, Stefan FinsteleAbstract:Corrosion of steel canisters, stored in a repository forspent fuel and high-level waste, leads to hydrogen gas generation in thebackfilled emplacement tunnels, which may significantly affect long-termrepository safety. Previous modeling studies used a constant H2generation rate. However, iron corrosion and H2 generation rates varywith time, depending on factors such as water chemistry, wateravailability, and water contact area. To account for these factors andfeedback mechanisms, we developed a chemistry model related to ironcorrosion, coupled with two-phase (liquid and gas) flow phenomena thatare driven by gas Pressure Buildup and water consumption. Resultsindicate that if H2 generation rates are dynamically calculated based ona chemistry model, the degree and extent of gas Pressure Buildup are muchsmaller compared to a simulation in which the coupling between flow andreactive transport mechansism is neglected.
Amanat U. Chaudhry - One of the best experts on this subject based on the ideXlab platform.
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Oil Well Testing Handbook - Chapter 5 – Pressure Buildup Analysis Techniques for Oil Wells
Oil Well Testing Handbook, 2004Co-Authors: Amanat U. ChaudhryAbstract:Pressure Buildup testing is the most familiar transient well-testing technique, which has been used extensively in the petroleum industry. Basically, the test is conducted by producing a well at a constant rate for some time, shutting the well in (usually at the surface), allowing the Pressure to build up in the wellbore, and recording the down-hole Pressure in the wellbore as a function of time. From these data, it is possible to estimate the formation permeability and current drainage area Pressure, and to characterize damage or stimulation and reservoir heterogeneity or boundaries frequently. In this chapter, ideal, actual Buildup tests, and Buildup tests in infinite-acting reservoirs and in developed (finite) reservoirs are discussed. Multiphase Buildup tests and the variable-flow-rate test analysis are also covered in detail. This chapter treats Pressure Buildup test analysis and presents methods for estimating formation characteristics such as the reservoir permeability, skin factor, wellbore damage, and improvement evaluation, including average Pressure for well drainage areas and the entire reservoir. In addition, analysis methods for after flow-dominated Pressure Buildup data are presented to identify a linear flow, near-wellbore permeability changes or boundaries using both accurate Pressure and total after flow fluid rate.
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Gas Well Testing Handbook - Chapter 6 – Fundamentals of Pressure Buildup Analysis Methods
Gas Well Testing Handbook, 2003Co-Authors: Amanat U. ChaudhryAbstract:This chapter discusses Pressure Buildup test. It is the simplest test that can be run on a gas well. If the effects of wellbore storage can be determined, much useful information can be obtained. This information includes permeability, “k”, apparent skin factor, s′, and average reservoir Pressure, ¯P R . The test consists of flowing the well at a constant rate, q sc for a period of time, t p , shutting the well in (at Δt = 0), and measuring wellbore Pressure increase with shut-in time, Δt. Horner developed the test, and this method of analysis is generally considered the best. Other conventional methods of analysis include the Horner plot, the Miller-Dyes-Hutchinso plot, and the Muskat plot. Horne showed that a plot of the shut-in Pressure, p ws versus log (t p + Δt)/Δt results in a straight line for an infinite-acting reservoir. In the Buildup tests, “t” refers to the drawdown period prior to a Buildup and Δt refers to the shut-in or Buildup time. Matthews, Brons, and Hazebroek (MBH), extended the application of the Horner plot to finite reservoirs. A Buildup test is always preceded by a drawdown, and the Buildup data are directly affected by this drawdown. Usually, the drawdown starts from a stabilized reservoir condition represented by the stabilized reservoir Pressure.
Nattawut Suwannapum - One of the best experts on this subject based on the ideXlab platform.
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Analysis of Heat–Mass Transport and Pressure Buildup Induced inside Unsaturated Porous Media Subjected to Microwave Energy Using a Single (TE10) Mode Cavity
Drying Technology, 2011Co-Authors: Nattawut Suwannapum, Phadungsak RattanadechoAbstract:This article presents the two-dimensional numerical analysis of heat and mass transport and Pressure built up inside an unsaturated porous packed bed under microwave energy at a frequency of 2.45 GHz using a rectangular waveguide (TE10 mode). The unsaturated porous packed beds were composed by glass beads, water, and air. The samples were prepared by compacting uniformly with various thicknesses δ = 30, 50, and 80 mm and particle sizes d = 0.15 mm (fine packed bed) and 0.4 mm (coarse packed bed), respectively. A proposed model used to investigate heat–mass transport and Pressure Buildup phenomena inside the porous packed bed in which the rectangular waveguide with varying glass bead sizes and sample thicknesses was inserted. The results show that the effect of particle sizes and thicknesses of porous packed bed are primary factors determining heat and mass transport with multiphase flow. These findings can explain the phenomena taking place inside unsaturated porous media in a microwave drying process usi...
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analysis of heat mass transport and Pressure Buildup induced inside unsaturated porous media subjected to microwave energy using a single te10 mode cavity
Drying Technology, 2011Co-Authors: Nattawut Suwannapum, Phadungsak RattanadechoAbstract:This article presents the two-dimensional numerical analysis of heat and mass transport and Pressure built up inside an unsaturated porous packed bed under microwave energy at a frequency of 2.45 GHz using a rectangular waveguide (TE10 mode). The unsaturated porous packed beds were composed by glass beads, water, and air. The samples were prepared by compacting uniformly with various thicknesses δ = 30, 50, and 80 mm and particle sizes d = 0.15 mm (fine packed bed) and 0.4 mm (coarse packed bed), respectively. A proposed model used to investigate heat–mass transport and Pressure Buildup phenomena inside the porous packed bed in which the rectangular waveguide with varying glass bead sizes and sample thicknesses was inserted. The results show that the effect of particle sizes and thicknesses of porous packed bed are primary factors determining heat and mass transport with multiphase flow. These findings can explain the phenomena taking place inside unsaturated porous media in a microwave drying process usi...
Volker Schoeppner - One of the best experts on this subject based on the ideXlab platform.
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discrete element simulations and validation tests investigating solids conveying processes with Pressure Buildup in single screw extruders
PROCEEDINGS OF PPS-31: The 31st International Conference of the Polymer Processing Society – Conference Papers, 2016Co-Authors: Johannsebastian Lessmann, Volker SchoeppnerAbstract:The goal of this contribution is to describe a method of simulating solids-conveying processes in single screw extruders which include a defined back Pressure leading to a resulting Pressure Buildup in the screw channel. To do so, use is made of the Discrete Element Method. Material parameters are presented, as well as details concerning the contact model used and the simulation tool EDEM. Additionally, a test setup is presented which has been used to validate the solids-conveying simulations. Results are shown for both simulations and experimental tests. Comparing the results from simulations and measurements shows acceptable conformity. Such simulations and experimental tests are crucial in order to better understand the Buildup of Pressure in high-speed single-screw extruders.