International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395 -0056
Volume: 04 Issue: 04 | Apr -2017
p-ISSN: 2395-0072
www.irjet.net
A review on analysis of air water two phase flow in conventional channel Jagat B. Shihori1, Krishna Kumar2 1PG
Student, Department of Mechanical Engineering, SVMIT College Bharuch, Gujarat, India Professor, Department of Mechanical Engineering, SVMIT College Bharuch, Gujarat, India ---------------------------------------------------------------------***--------------------------------------------------------------------2Assistant
Abstract – Two-phase flow has a wide range of
engineering applications such as in the chemical & petroleum industries, refrigerators, micro reactors, ultra filtration plants. The hydrodynamic characteristics of the flow plays a very important role in the micro reactor design. generally the laminar flow occurs in conventional channel, so to achieve higher mass transfer large radial diffusion required to achieve. Radial mixing can be achieved in multiphase micro reactors. In this work, the hydrodynamic behavior of a air-water flow in capillary circular conventional-channel studying numerically and experimentally. Taylor flow pattern is main pattern occurring in two phase flow regime. It is most important flow regime to achieve higher mass transfer and heat transfer. Taylor flow enhances gas–liquid mass transfer. it has been observed that Taylor flow hydrodynamics and mass transfer performance are slug length and bubble velocity dependent. To study the effect of flow & geometrical properties on slug length and bubble velocity in taylor flow is important characteristic. Key Words: Air water two phase flow, conventional channel, Taylor bubble flow, two phase flow, slug flow
connects the liquid slugs. The primary advantages offered by Taylor flow are the greatly reduced axial and improved radial mixing which can augment two or three phase reactions or enhance gas–liquid mixing. Taylor flow provides larger contact area between gas and liquid slugs which improves mass transfer. High surface-area-to-volume ratio increases its importance in design of heat exchangers and micro reactors. Due to complex nature of Taylor flow regime, it has required more computation effort than other flow pattern.
1.1 GOVERNING EQUATIONS The governing equations of the on multi-phase stream are recorded beneath.
Equation of continuity
Volume fraction equation
1. INTRODUCTION Two-phase flow main characteristic is the presence of interfaces, due to which the discontinuities presents in the properties over the interfaces and due to interface it can take number of shapes based on geometric configuration, inlet condition and superficial velocity of phases. The accurate measurement of two-phase flow parameters has always been a key parameter. Different flow regimes in two phase flow by variation of the gas–liquid superficial velocity ratios. Difference In horizontal and vertical channel orientation is effect of gravity on flows.in case of horizontal flow gravity acts perpendicular to flow. In vertical orientation, It acts opposite to flow direction if flow is upward direction and it acts in supporting direction if flow is downward direction. Thus channel orientation effects the flow regime greatly .mass transfer, pressure drop largely depends on particular flow pattern. Taylor flow pattern is very important flow patterns in different flow pattern occurring in two phase flow and because great mass transfer can be achieved in this flow pattern. Taylor flow is characterized by gas bubbles that almost fill the channel, separated by liquid slugs. The gas slugs are separation occurs by liquid slugs. Small liquid film © 2017, IRJET
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Momentum equation
1.2 Volume of Fluid (VOF) Model In the present study, VOF method is chosen to simulate twophase flow. Simulation carried out with unsteady approach all simulations. The VOF model is the major multiphase model used in commercial CFD packages to capture interface. In VOF method, the interface is tracked by the solution of a continuity equation for the volume fraction of phases. The interface is tracked by geometric reconstruction scheme using the piecewise linear.
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