Engine downsizing is potentially one of the most effective strategies being explored to improve fuel economy. A main problem of downsizing using a turbocharger is the small range of stable functioning of the turbocharger centrifugal compressor at high boost pressures. Several techniques were studied to increase the compressor operating range without sacrificing the compressor...

In this paper, the nanoclay particles were introduced as mobile adsorbents in oil reservoirs to adsorb the asphaltenes, reduce the viscosity and enhance the dispersion. The objective of this paper is experimental investigation of enhanced heavy oil recovery using in situ nanoparticles for the first time. Moreover, two thermal analysis methods (thermogravimetry and differential...

This study concerns an approach for dolomite quantification and stoichiometry calculation by using X-ray diffractometry coupled with cell and Rietveld refinements and equipped with a newly substantial database of dolomite composition. A greater accuracy and precision are obtained for quantifying dolomite as well as other mineral phases and calculating dolomite stoichiometry...

The present paper investigates and compares the performance of three configurations of Gas Turbine systems allowing cogeneration of heat and electricity, on the basis of an irreversible regenerative Brayton-Joule cycle. The proposed model is developed for two different cycle constraints, namely, an imposed heat transfer rate released by the fuel combustion, or an imposed maximum...

The numerical model for the depressurization of methane hydrates in a confined reservoir is presented based on mass conservation in porous media, incorporating multiphase flow theory and kinetics of gas hydrate dissociation. The universal implicit difference method is adopted, and the corresponding computer program is developed. During the production of the hydrate reservoir...

This study investigates the effects of various operating conditions in spark ignition engines via an exergy analysis. A thermodynamic cycle model including compression, combustion and expansion processes was used for investigation. Induction and exhaust processes were computed with a simple approximation method. The principles of the second law were applied to the cycle model to...

Characterizing the uncertainty in the subsurface is an important step for exploration and extraction of natural resources, the storage of nuclear material and gasses such as natural gas or CO2. Imaging the subsurface can be posed as an inverse problem and can be solved using the geostatistical approach [Kitanidis P.K. (2007) Geophys. Monogr. Ser. 171, 19-30, doi:10.1029/171GM04...

It is becoming more and more common to use assisted history matching methods to find different combinations of reservoir simulation models that agree with production data. Models with a large number of cells contain millions of unknown parameters and selecting the correct property values can be difficult. In practice, not all are important but finding which parts of the reservoir...

Oxygen production processes using adsorbents for application to CCS technologies (Carbon Capture and Storage) offer potential cost benefits over classical cryogenics. In order to model adsorption processes an approach using three size scales has been developed. This work is being conducted in the framework of the DECARBit European research project. The first scale is at the size...

As engine technologies become increasingly complex and engines are driven to new operating points, understanding transient phenomena is important to ensure reliable engine operation. Unlike Reynolds Averaged Navier-Stokes (RANS) studies that only provide cycle-averaged information, Large Eddy Simulation (LES) studies are capable of simulating cycle-to-cycle dynamics. In this work...

The aim of seismic imaging is to reconstruct the reflectivity associated with subsurface structures. In standard imaging techniques, the reflectivity model usually starts a few meters below the surface, the actual depth being dependent on data acquisition parameters and the mute used to remove stretching of first arrivals after normal moveout correction. In this paper, we...

In this paper, we present a model for predicting the average slug frequency in horizontal gas/liquid pipe flow. The model considers the probability of slug formation if slugs are triggered at the antinodes of a sinusoidal perturbation, along the pipe at the frequency of oscillation of the interface. A slug is assumed to form if and only if triggered at a space-time far enough...

The accurate modeling of the fast-fill process occurring in Compressed Natural Gas (CNG) fuelled vehicle storage cylinders is a complex process and should be thoroughly studied. Final in-cylinder conditions should meet appropriate cylinder safety standards. The composition of natural gas plays an important role on its thermodynamic properties and consequently, on the fast-fill...

In this article, we describe a novel unsupervised spectral image segmentation algorithm. This algorithm extends the classical Gaussian Mixture Model-based unsupervised classification technique by incorporating a spatial flavor into the model: the spectra are modelized by a mixture of K classes, each with a Gaussian distribution, whose mixing proportions depend on the position...

In this paper, we consider adaptive numerical simulation of miscible displacement problems in porous media, which are modeled by single phase flow equations. A vertex-centred finite volume method is employed to discretize the coupled system: the Darcy flow equation and the diffusion-convection concentration equation. The convection term is approximated with a Godunov scheme over...

We present a preliminary work to simulate gas injection in deep aquifers. Unsteady single-phase flows are considered. We compare Discrete Duality Finite Volume (DDFV, Discrete Duality Finite Volume) and Discontinuous Galerkin (DG, Discontinuous Galerkin) schemes applied to discretize the diffusive term. The second-order backward differentiation formula is used for the time...

The aim of this work is to study the automatic characterization of Naturally Fractured Vuggy Reservoirs via well test analysis, using a triple porosity-dual permeability model. The inter-porosity flow parameters, the storativity ratios, as well as the permeability ratio, the wellbore storage effect, the skin and the total permeability will be identified as parameters of the model...

Chemical flooding is currently one of the most promising solution to increase the recovery of mature reservoirs. In Surfactant-Polymer (SP) processes, several parameters should be taken into account to estimate the return on investments: concentrations of the injected chemical species, slug sizes, initiation times, residual oil saturation, adsorption rates of the chemical species...

The proposed method regularizes as far as possible some verticals of a hex-dominant basin mesh; this regularization is used to optimize the numerical simulation of hydrocarbons flow in basins. The studied basins contain faults and constitute complex geometries.This mesh optimization is adapted for a new way to mesh basins called the “Constrained Grid Method” (CGM). Data...

Subsurface flows are influenced by the presence of faults and large fractures which act as preferential paths or barriers for the flow. In literature models were proposed to handle fractures in a porous medium as objects of codimension 1. In this work we consider the case of a network of intersecting fractures, with the aim of deriving physically consistent and effective...

We present a fracture model in a poro-elastic medium. The model describes the fracture as a curve or surface according to the dimension, the width of the crack being included into the equation of flow in the fracture. The discretization uses mixed finite elements for the fluid and continuous finite elements for the porous medium’s displacement. The numerical scheme is solved by...