Fundamentals 3 Multiphase Flow

In part II of the present report the nature and molecular characteristics of asphaltene and wax deposits from petroleum crudes are discussed. The field experiences with asphaltene and wax deposition and their related problems are discussed in part III. In order to predict the phenomena of asphaltene deposition one has to consider the use of the molecular thermodynamics of fluid phase equilibria and the theory of colloidal suspensions. In part IV of this report predictive approaches of the behavior of reservoir fluids and asphaltene depositions are reviewed from a fundamental point of view. This includes correlation and prediction of the effects of temperature, pressure, composition and flow characteristics of the miscible gas and crude on (i) Onset of asphaltene deposition (ii) Mechanism of asphaltene flocculation. The in situ precipitation and flocculation of asphaltene is expected to be quite different from the controlled laboratory experiments. This is primarily due to the multiphase flow through the reservoir porous media, streaming potential effects in pipes and conduits, and the interactions of the precipitates and the other in situ material presnet. In part V of the present report the conclusions are stated and the requirements for the development of successful predictive models for the asphaltene deposition and flocculation are discussed. 

Young 5941 derived a set of fundamental equations for gas-droplet multiphase flows in which small liquid droplets polydisperse... 

Brennen, C. E., Fundamentals of Multiphase Flow". Cambridge University Press, New York, NY (2005). 

This chapter is therefore intended to describe the fundamental issues on PIV technique in brief, the versatility of PIV techniques from the viewpoint of its hardware components as well as the resolved dimensions. The chapter is also intended to discuss the state of the art in the special PIV techniques (sometime with the aid of other supplementary technique) applied to the measurement of multiphase flows. Note that, the emphasis in this chapter is on the methodology of PIV techniques instead of details of the individual study on any research topic. 

Interphase coupling terms make multiphase flows fundamentally different from single-phase flows. The formulation of these terms and, therefore, of interphase exchange coefficients must proceed carefully, with attention being paid to the force balance for a single particle and to any possible inconsistencies. The interphase coupling terms must satisfy the following relation ... 

Kolev NI (2002) Multiphase Flow Dynamics 1 Fundamentals. Springer, Berlin Kuipers JAM, van Swaaij WPM (1997) Application of Computational Fluid Dynamics to Chemical Reaction Engineering. Reviews in Chemical Engineering 13 (3) 1-118. 

Kolev NI (2002) Multiphase Flow Dynamics 1 Fundamentals. Springer, Berlin... 

The statistical description of multiphase flow is developed based on the Boltzmann theory of gases [37, 121, 93, 11, 94, 58, 61]. The fundamental variable is the particle distribution function with an appropriate choice of internal coordinates relevant for the particular problem in question. Most of the multiphase flow modeling work performed so far has focused on isothermal, non-reactive mono-disperse mixtures. However, in chemical reactor engineering the industrial interest lies in multiphase systems that include multiple particle t3q)es and reactive flow mixtures, with their associated effects of mixing, segregation and heat transfer. 

In this section the application of multiphase flow theory to model the performance of fluidized bed reactors is outlined. A number of models for fluidized bed reactor flows have been established based on solving the average fundamental continuity, momentum and turbulent kinetic energy equations. The conventional granular flow theory for dense beds has been reviewed in chap 4. However, the majority of the papers published on this topic still focus on pure gas-particle flows, intending to develop closures that are able to predict the important flow phenomena observed analyzing experimental data. Very few attempts have been made to predict the performance of chemical reactive processes using this type of model. 

Fox, R. O. 2007 Introduction and fundamentals of modeling approaches for polydisperse multiphase flows, in Computational Models for Turbulent Multiphase Reacting Flows, Vienna Springer, pp. 1 0. 

The chapter begins with the fundamental measurements of resistance, capacitance, charge, and particle force. We proceed with flow measurements with various probes followed by a listing of some commercial electrostatic instruments. Nonelectrosatic measurements in multiphase flow such as the laser-Doppler anemometer, radioactive tracers, and stroboscopic techniques (Polaskowski, et. al, 1995 Soo, 1982) have not been discussed unless in relation to an electrostatic effect. 

The goal of this chapter is to describe the fluid motion laws in a very general way based on flow systems rather than vahd for special apparatus in narrow ranges of velocities and flttid properties. At first, fundamental laws of one-phase flows are presented because they are the basis for two- and multiphase flow. 

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