EXPERIMENTAL DATA SET NO. 26: THE DISPERSION AND ATTENUATION OF SMALL AMPLITUDE STANDING WAVES AND THE PROPAGATION OF ACOUSTIC PRESSURE PULSES IN BUBBLY AIR/WATER TWO-PHASE FLOWS

1992 ◽  
Vol 6 (1-4) ◽  
pp. 353-371
Author(s):  
Arthur E. Ruggles
Author(s):  
Adriana Greco ◽  
Rita Mastrullo ◽  
Alfonso W. Mauro ◽  
Giuseppe P. Vanoli

A 962 points database for refrigerants two-phase flows by Greco A. and Vanoli G.P. was statistically compared to four widely used prediction methods by Lockhart and Martinelli, Chawla, Theissing and Mu¨ller-Steinhagen and Heck in order to determine the best one. The experimental points are in a wide range of operating conditions for six pure or mixed refrigerants (R134a, R22, R407C, R507A, R410A and R404A) during evaporation in a smooth horizontal tube of 6 m length and 6 mm ID.


Author(s):  
Caleb S. Brooks ◽  
Yang Liu ◽  
Takashi Hibiki ◽  
Mamoru Ishii

A void fraction covariance in the expression for area-averaged local relative velocity has been assumed to be one by current and past researchers. Similarly, in a multi-bubble group approach, void covariances for each bubble group appear in the group area-averaged relative velocity expressions. The covariance terms have been analyzed with a substantial database from literature including upward flow in pipe diameters of 1.27 cm to 15.2 cm, downward flow in pipe diameters of 2.54 cm and 5.08 cm, and upward flow in an annulus (Dh = 1.9cm) under adiabatic, boiling, and condensing conditions. Simple relations are proposed to specify the covariance in order to improve the prediction of area-averaged local relative velocity. The correlations were found to agree well with the experimental data for the flow configurations and conditions analyzed.


Author(s):  
Abubakr Ibrahim ◽  
Buddhika Hewakandamby ◽  
Zhilin Yang ◽  
Barry Azzopardi

Effect of injector geometry on two phase flows is of profound importance to industry. If the injection method is found to vary the flow characteristics dramatically, it can be employed to obtain desirable two phase flow regimes/attributes and avoid rather unsought conditions. This could potentially save a lot of costs in the extraction and transportation of oil and gas as well as in many other applications. Moreover, the issue of flow development and dependency on the injection conditions is essential when modelling two phase flows. A lot of experimental data and empirical models may have been developed based on systems that may not be fully developed. Therefore, inaccurate modelling of the physical interactions of the flow gets adopted, and hence large divergence between models and experimental data produced by different researchers often transpires. Most of the published studies on entrance effect were conducted on air-water or steam-water systems because of their relevance to heat transfer units in the nuclear industry. This paper presents an extensive experimental investigation into the issue of flow development using two approaches; measuring void fraction at five axial stations along the test section, and using different geometries for bubble injection into the base of the pipe. The study focuses on how the entrance effect is influenced by the liquid viscosity. The experiments were conducted in a 127 mm diameter vertical pipe. The investigation is achieved by contrasting 180 runs produced using three different injector geometries, the runs were repeated using 4 different oil viscosities, making 2160 experimental run. Gas superficial velocity (Ugs) was varied between 0.01–5.40 m/s, while liquid superficial velocity (Uls) between 0.07–0.86 m/s. The viscosities investigated span between 4.0 cP up to 104.6 cP. The void fraction was measured using Electrical Capacitance Tomography (ECT) and the Wire Mesh Sensor (WMS). That in addition to differential pressure measurements.


SPE Journal ◽  
2016 ◽  
Vol 22 (02) ◽  
pp. 470-479 ◽  
Author(s):  
Saeid Khorsandi ◽  
Changhe Qiao ◽  
Russell T. Johns

Summary A compositional reservoir simulator that uses a predictive microemulsion phase-behavior model is essential for accurate estimation of oil recovery from surfactant/polymer (SP) floods. Current chemical-flooding simulators, however, use Hand's model (Hand 1939) for phase-behavior calculation. Hand's model can reasonably fit a limited set of experimental data, such as those of a salinity scan, but because it is empirical, it cannot predict phase behavior outside the matched data set. Hydrophyllic/lypophyllic difference (HLD) and net-average-curvature (NAC) equation of state (EOS) (Acosta et al. 2003) has shown great performance for tuning and prediction of experimental data. In this paper, the EOS model with the extension to two-phase regions has been incorporated for the first time into UTCHEM (2000) and our in-house general-purpose compositional simulator, PennSim (2013). All Winsor regions (Type II−, II+, III, and IV) are modeled by use of a consistent physics-based EOS model without the need for Hand's approach. The new simulator is therefore able to account correctly for gridblock properties, which can vary temporally and spatially, and significantly improve the modeling of phase behavior and oil recovery. The results show excellent agreement between UTCHEM and PennSim both in composition space and for composition/saturation profiles for the 1D simulation. The effects of varying pressure, temperature, equivalent alkane carbon number (EACN), and salinity on recoveries are demonstrated also in 1D simulations.


1989 ◽  
Vol 111 (2) ◽  
pp. 467-473 ◽  
Author(s):  
A. E. Ruggles ◽  
R. T. Lahey ◽  
D. A. Drew ◽  
H. A. Scarton

A two-fluid model is presented that can be used to predict the celerity and attenuation of small-amplitude harmonic disturbances in bubbly two-phase flow. This frequency-dependent relationship is then used to predict the propagation of small-amplitude pressure perturbations through the use of Fourier decomposition techniques. Predictions of both standing waves and propagating pressure perturbations agree well with existing data. The low and high-frequency limits of the celerities predicted by the model are examined and their relationship to critical flow rate is demonstrated. Some limitations of the interfacial pressure model employed in conventional critical flow analysis are exposed and the implications to the prediction of critical flow rate are discussed.


1982 ◽  
Vol 116 ◽  
pp. 343-362 ◽  
Author(s):  
T. G. Theofanous ◽  
J. Sullivan

Turbulence measurements in dispersed-bubble two-phase pipe flow, using laser velocimetry techniques, are presented. The turbulence-intensity measurements show a strong dependence on the quality of the flow. A theoretical basis for the prediction of turbulence levels in two-phase flows is proposed. The approach is applied to dispersed-gas/liquid (bubbly) and solid/gas (particulate) two-phase flows, for which experimental data are available, with excellent results.


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