Multiphase Flow Measurement Techniques—A Review

1993 ◽  
Vol 115 (3) ◽  
pp. 151-161 ◽  
Author(s):  
V. S. V. Rajan ◽  
R. K. Ridley ◽  
K. G. Rafa
Keyword(s):  
Multiphase Flow ◽  
Mass Flow ◽  
Measurement Techniques ◽  
Extensive Literature ◽  
Two Phase ◽  
Flow Rates ◽  
Gas Phases ◽  
Mass Flow Rates ◽  
The Individual ◽  
Areas Of Interest

This paper is a review of current techniques available for measuring the velocity and composition in multiphase streams, to obtain the mass flow rate of the individual phases. An extensive literature search was conducted on the topic and related areas of interest. The major difficulty in measuring both the velocity and composition of multiphase streams is in dealing with the wide variety of flow regimes which are possible in multiphase flow in pipes. A device which is suitable for accurate velocity measurement in multiphase flows is not commercially available. However, if the flow is well mixed, it should be possible to calibrate a simple device, such as a nozzle or a venturi, to provide accurate total volumetric flow rates. Several commercial in-line static mixing devices are suitable for low gas concentrations (≤ 10 percent) and with superficial gas velocities higher than 10 m/s. For lower gas velocities and high gas concentrations, the suitability of these in-line mixers will have to be further assessed experimentally. Other techniques such as cross-correlation are known for two-phase flow velocity measurements, and the results of these applications look promising. A multiphase compositional meter to monitor the concentration of oil, water, and gas phases flowing in a pipeline, used in combination with a suitable homogenizer and a velocity meter, would facilitate measurement of the mass flow rates of the individual phases. Further work must be done to develop this concept.

A NEW METHOD OF MEASURING TWO-PHASE MASS FLOW RATES IN A VENTURI

2009 ◽  
Vol 21 (1-2) ◽  
pp. 157-168 ◽  
Author(s):  
He Peixiang ◽  
Cees W. M. van der Geld ◽  
Claudio Alimonti ◽  
Julio Cesar Passos
Keyword(s):  
Mass Flow ◽  
New Method ◽  
Two Phase ◽  
Flow Rates ◽  
Mass Flow Rates

A Comparison of a Mono, Twin and Double Scroll Turbine for Automotive Applications

2015 ◽  
Author(s):  
Jason Walkingshaw ◽  
Georgios Iosifidis ◽  
Tobias Scheuermann ◽  
Dietmar Filsinger ◽  
Nobuyuki Ikeya
Keyword(s):  
Mass Flow ◽  
Flow Characteristics ◽  
High Mass ◽  
Flow Rates ◽  
Engine Simulation ◽  
Engine Model ◽  
Trade Offs ◽  
Mass Flow Rates ◽  
The Individual ◽  
The Impact

As a means of meeting ever increasing emissions and fuel economy demands car manufacturers are using aggressive engine downsizing. To maintain the power output of the engine turbocharging is typically used. Due to the miss-match of the mass flow characteristics of the engine to the turbocharger, at low engine mass flow rates, the turbocharger can suffer from slow response known as “Turbolag”. Mono-scroll turbines are capable of providing good performance at high mass flow rates and in conjunction with low inertia mixed flow turbines can offer some benefits for transient engine response. With a multi-entry system the individual volute sizing can be matched to the single mass flow pulse from the engine cylinders. The exhaust pulse energy can be better utilised by the turbocharger turbine improving turbocharger response, while the interaction of the engine exhaust pulses can be better avoided, improving the scavenging of the engine. The behaviour of a mono-scroll turbocharger with the engine using engine simulation tools has been well established. What requires further investigation is the comparison with multi-entry turbines. CFD (Computational Fluid Dynamics) has been used to examine the single admission behaviour of a twin and double scroll turbine. Turbocharger gas stand maps of the multi-entry turbines have been measured at full and single admission. This data has been used in a 0D engine model. In addition, the turbine stage has been tested on the engine and a validation of the engine model against the engine test data is presented. Using the validated engine model a comparison has been made to understand the differences in the sizing requirements of the turbine and the interaction of the mono-scroll and multi-entry turbines with the engine. The impact of the different efficiency and mass flow rate trends of the mono and multi-entry turbochargers are discussed and the trade-offs between the design configurations regarding on engine behaviour are investigated.

Shell and tube heat exchanger thermal-hydraulic analysis equipped with baffles and corrugated tubes filled with non-Newtonian two-phase nanofluid

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ali Akbar Abbasian Arani ◽  
Reza Moradi
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Transfer Coefficient ◽  
Mass Flow ◽  
Two Phase ◽  
Flow Rates ◽  
Content Type ◽  
Mass Flow Rates ◽  
Shell And Tube

Purpose Using turbulators, obstacles, ribs, corrugations, baffles and different tube geometry, and also various arrangements of these components have a noticeable effect on the shell and tube heat exchangers (STHEs) thermal-hydraulic performance. This study aims to investigate non-Newtonian fluid flow characteristics and heat transfer features of water and carboxyl methyl cellulose (H2O 99.5%:0.5% CMC)-based Al2O3 nanofluid inside the STHE equipped with corrugated tubes and baffles using two-phase mixture model. Design/methodology/approach Five different corrugated tubes and two baffle shapes are studied numerically using finite volume method based on SIMPLEC algorithm using ANSYS-Fluent software. Findings Based on the obtained results, it is shown that for low-mass flow rates, the disk baffle (DB) has more heat transfer coefficient than that of segmental baffle (SB) configuration, while for mass flow rate more than 1 kg/s, using the SB leads to more heat transfer coefficient than that of DB configuration. Using the DB leads to higher thermal-hydraulic performance evaluation criteria (THPEC) than that of SB configuration in heat exchanger. The THPEC values are between 1.32 and 1.45. Originality/value Using inner, outer or inner/outer corrugations (outer circular rib and inner circular rib [OCR+ICR]) tubes for all mass flow rates can increase the THPEC significantly. Based on the present study, STHE with DB and OCR+ICR tubes configuration filled with water/CMC/Al2O3 with f = 1.5% and dnp = 100 nm is the optimum configuration. The value of THPEC in referred case was 1.73, while for outer corrugations and inner smooth, this value is between 1.34 and 1.57, and for outer smooth and inner corrugations, this value is between 1.33 and 1.52.

Bounds on Two-Phase Flow: Part II — Void Fraction in Circular Pipes

2005 ◽  
Author(s):  
M. M. Awad ◽  
Y. S. Muzychka
Keyword(s):  
Experimental Data ◽  
Void Fraction ◽  
Mass Flow ◽  
Liquid Fraction ◽  
Published Data ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Rates ◽  
Working Fluids ◽  
Mass Flow Rates

Theoretical and empirical models for the gas void fraction (α) are reviewed. Simple rules are developed for obtaining rational bounds for the void fraction in two-phase flow. The lower bound is based on the separate cylinders formulation for turbulent-turbulent flow that uses the Blasius equation to predict the Fanning friction factor. The upper bound is based on the Butterworth relationship that represents well the Lockhart-Martinelli correlation. These two bounds are reversed in the case of liquid fraction (1−α). The bounds models are verified using published experimental data of void fraction versus mass quality at constant mass flow rate. The published data include different working fluids such as R-12 and R-22 at different pipe diameters, different pressures, and different mass flow rates. It is shown that the published data can be well bounded for a wide range of mass qualities, pipe diameters, pressures and mass flow rates. Further comparisons are made using the published experimental data of void fraction (α) and liquid fraction (1−α) versus the Lockhart-Martinelli parameter (X), for different working fluids such as R-12, R-22 and air-water mixtures.

Experimental and Computational Characterization of Flow Rates in a Multiple-Passage Gas Turbine Combustor Swirler

2017 ◽  
Author(s):  
Timothy J. Erdmann ◽  
David L. Burrus ◽  
Alejandro M. Briones ◽  
Scott D. Stouffer ◽  
Brent A. Rankin ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Mass Flow ◽  
Flow Rate ◽  
Total Flow ◽  
Gas Turbine Combustor ◽  
Flow Rates ◽  
Air Mass ◽  
Flow Configuration ◽  
Mass Flow Rates ◽  
The Individual

One of the challenges of gas turbine combustor research is to accurately measure and model air mass flow rates through complex air injection schemes. Accurate measurements and computations of air mass flow rates are necessary for determining air and fuel distributions, which influence a range of combustor operation and performance characteristics. Experimental and computational studies were performed on a representative gas turbine combustor swirler. The swirler geometry consists of four component flows: two co-rotating annular axial swirls, one radial swirl, and cooling on the periphery of the swirler. The purpose of this study is to compare measured and computed air mass flow rates in a realistic swirler with a complex geometry and to quantify the magnitude of the interaction effects between air passages. The measurements of the air mass flow rates were performed using a calibrated air flow stand. The computations were performed using commercial Computational Fluid Dynamics (CFD) tools. Comparisons between measured and computed air mass flow rates show good agreement for the individual and total flow configurations. Significant interaction effects among the swirling flows are observed when all of the air passages are open. The radial swirl mass flow rate decreases by 2.7% and the outer axial swirl mass flow rate increases by 3.8% when the individual component flow configuration is compared to the total flow configuration. The computed mass flow rates demonstrate that the interactions among the swirl flows create a significant change in mass flow distribution within the swirler.

scholarly journals Net-exergetic, hydraulic and thermal optimization of coaxial heat exchangers using fixed flow conditions instead of fixed flow rates

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Tobias Blanke ◽  
Markus Hagenkamp ◽  
Bernd Döring ◽  
Joachim Göttsche ◽  
Vitali Reger ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Laminar Flow ◽  
Mass Flow ◽  
Flow Rate ◽  
Heat Exchangers ◽  
Circular Ring ◽  
Flow Conditions ◽  
Flow Rates ◽  
Mass Flow Rates ◽  
Pipe Radius

AbstractPrevious studies optimized the dimensions of coaxial heat exchangers using constant mass flow rates as a boundary condition. They show a thermal optimal circular ring width of nearly zero. Hydraulically optimal is an inner to outer pipe radius ratio of 0.65 for turbulent and 0.68 for laminar flow types. In contrast, in this study, flow conditions in the circular ring are kept constant (a set of fixed Reynolds numbers) during optimization. This approach ensures fixed flow conditions and prevents inappropriately high or low mass flow rates. The optimization is carried out for three objectives: Maximum energy gain, minimum hydraulic effort and eventually optimum net-exergy balance. The optimization changes the inner pipe radius and mass flow rate but not the Reynolds number of the circular ring. The thermal calculations base on Hellström’s borehole resistance and the hydraulic optimization on individually calculated linear loss of head coefficients. Increasing the inner pipe radius results in decreased hydraulic losses in the inner pipe but increased losses in the circular ring. The net-exergy difference is a key performance indicator and combines thermal and hydraulic calculations. It is the difference between thermal exergy flux and hydraulic effort. The Reynolds number in the circular ring is instead of the mass flow rate constant during all optimizations. The result from a thermal perspective is an optimal width of the circular ring of nearly zero. The hydraulically optimal inner pipe radius is 54% of the outer pipe radius for laminar flow and 60% for turbulent flow scenarios. Net-exergetic optimization shows a predominant influence of hydraulic losses, especially for small temperature gains. The exact result depends on the earth’s thermal properties and the flow type. Conclusively, coaxial geothermal probes’ design should focus on the hydraulic optimum and take the thermal optimum as a secondary criterion due to the dominating hydraulics.

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