Visual Criteria for Measuring Two-phase Flow Rate in Venturi with Flow Homogenizer

2015 ◽  
Vol 137 (8) ◽  
Author(s):  
Sangho Sohn ◽  
Jaebum Park ◽  
Dong-Wook Oh
Keyword(s):  
Flow Rate ◽  
High Speed ◽  
Two Phase Flow ◽  
Volume Fraction ◽  
Differential Pressure ◽  
Phase Flow ◽  
Two Phase ◽  
3 Dimensional ◽  
Lower Amplitude ◽  
Gas Volume

A simple use of Venturi might be used to measure two-phase flow rate within relatively low GVF(gas volume fraction). Upstream flow entering Venturi can be improved with installed flow homogenizer which is easily fabricated by 3-dimensional printer with multiple holes. Simultaneous measurement between high-speed flow visualization and dynamic differential pressure measurement was made to find visual criteria for two-phase flow rate measurement with different GVF ranged from 0% to 30%. It was observed that the two-phase flow rate can be reliably measured up to 15% of GVF using flow homogenizer. FFT(Fast-Fourier Transform) results proved that the long flow homogenizers (type 2 and 4) showed a lower amplitude of differential pressure (Δp) than the short flow homogenizers (type 1 and 3) respectively. So the optimized flow homogenizer can be useful to measure two-phase flow rate at low GVF.

Wet Gas Flow Metering Based on Differential Pressure and BSS Techniques

2011 ◽  
Vol 383-390 ◽  
pp. 4922-4927
Author(s):  
Peng Xia Xu ◽  
Yan Feng Geng
Keyword(s):  
Flow Rate ◽  
Liquid Flow ◽  
Gas Flow ◽  
Two Phase Flow ◽  
Liquid Flow Rate ◽  
Differential Pressure ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Metering ◽  
Wet Gas

Wet gas flow is a typical two-phase flow with low liquid fractions. As differential pressure signal contains rich information of flow parameters in two-phase flow metering, a new method is proposed for wet gas flow metering based on differential pressure (DP) and blind source separation (BSS) techniques. DP signals are from a couple of slotted orifices and the BSS method is based on time-frequency analysis. A good relationship between the liquid flow rate and the characteristic quantity of the separated signal is established, and a differential pressure correlation for slotted orifice is applied to calculate the gas flow rate. The calculation results are good with 90% relative errors less than ±10%. The results also show that BSS is an effective method to extract liquid flow rate from DP signals of wet gas flow, and to analysis different interactions among the total DP readings.

Analysis and Experimental Research on the Fluid–Solid Coupled Heat Transfer of High-Speed Motorized Spindle Bearing Under Oil–Air Lubrication

2020 ◽  
Vol 143 (7) ◽  
Author(s):  
Feng Gao ◽  
Weitao Jia ◽  
Yan Li ◽  
Dongya Zhang ◽  
Zhengliang Wang
Keyword(s):  
Heat Transfer ◽  
Temperature Rise ◽  
High Speed ◽  
Two Phase Flow ◽  
Volume Fraction ◽  
Phase Flow ◽  
Motorized Spindle ◽  
Two Phase ◽  
Spindle Bearing ◽  
Air Lubrication

Abstract For high-speed motorized spindle bearing, temperature rise is the primary factor that restricts the maximum speed of spindle and affects the stability of system. This paper addresses the lubrication and cooling of spindle bearing by exploiting the precise oil control and high cooling efficiency of oil–air lubrication. Enlightened by the bearing tribology and two-phase flow theory, a numerical model of oil–air two-phase flow heat transfer inside bearing cavity is created, with which the effects of operating condition and nozzle structure parameters on the temperature rise are studied. As the results show, with the elevation in speed, the heat generation increases rapidly, and despite the somewhat enhanced heat transfer effect, the temperature still tends to rise. Given the higher volume fraction of air than oil in the two-phase flow, the temperature rise of bearing is suppressed greatly as the air inlet velocity increases, revealing a remarkable cooling effect. When a single nozzle is used, the bearing temperature increases from the inlet to both sides, which peaks on the opposite side of the inlet. In case multiple evenly distributed nozzles are used, the high-temperature range narrows gradually, and the temperature distributions in the inner and outer rings tend to be consistent. With the increase in the nozzle aspect ratio, the airflow velocity drops evidently, which affects the heat dissipation, thereby resulting in an aggravated temperature rise. Finally, the simulation analysis is verified through experimentation, which provides a theoretical basis for selecting optimal parameters for the oil–air lubrication of high-speed bearing.

Analysis of Orifice Plate Differential Pressure Noise in Horizontal and Vertical Rising Gas-Water Two-Phase Flow

2010 ◽  
Author(s):  
Xianfa Li ◽  
Shuoping Zhong ◽  
Yanfei Sun
Keyword(s):  
Flow Rate ◽  
Two Phase Flow ◽  
Water Flow Rate ◽  
Differential Pressure ◽  
Orifice Plate ◽  
Vapor Flow ◽  
Phase Flow ◽  
Square Root ◽  
Two Phase ◽  
The Difference

It is an important achievement of modern techniques to determine the mass flow rate and the phase fraction of wet steam by measuring the orifice plate differential pressure noise. The orifice plate differential pressure noise of air-water two-phase flow in horizontal and vertical rising pipelines were analyzed. Kinds of calculation methods were tried to get the differential pressure noise. From the difference waveform of the differential pressure square root that the acquisition card got and the mean square root of the sample that got before, the first in first out (FIFO) principle was used to get the differential pressure noise. Result shows that the differential pressure noise has different level at different vapor flow rate with the same water flow rate, conclusions show that the two-parameter measurement by using orifice plate differential pressure noise may be possibly used in vertical rising gas-water two phase flow.

Unsteady Two-Phase Flow Analysis on Water Retarder Performance Using Sliding Mesh Technique and VOF Method

2015 ◽  
Author(s):  
Wonju Lee ◽  
Nahmkeon Hur
Keyword(s):  
High Speed ◽  
Two Phase Flow ◽  
Volume Fraction ◽  
Volume Ratio ◽  
Working Fluid ◽  
Water Volume ◽  
Phase Flow ◽  
Two Phase ◽  
Sliding Mesh ◽  
Mesh Technique

Hydraulic retarders are used as auxiliary brake system in heavy vehicles and high speed trains. A hydraulic retarder is composed of two parts, a rotor and a stator. When the system is activated, the working fluid is injected into the wheel and circulates between the rotor and stator vanes using the resisting torque of the stator to slow down the vehicle. The purpose of this research is to investigate a water retarder system and the details of flow characteristics of the water, and to investigate the device performance as well. The water retarder is basically composed of a rotor and a stator. In the present research, the rotor rotating speed is fixed at 2000 rpm. Since the performance characteristic of the water retarder is dependent upon the water volume ratio, different volume ratios have been investigated. In this paper water retarder simulations are carried out using CFD using sliding mesh technique. To capture the unsteady effects, the cases have been solved as transient simulations using standard k-ε turbulence model. The simulations have been solved as two phase flow, water and air. The results are compared for different water volume ratios. The result show that the air particles are accumulated in the center of the wheels forming a tube shape (doughnut shape) and water particles are at the outside, wrapping the air particles. In addition, torque values are sensitively dependent upon water volume fraction.

A Pressure-Based Two-Phase Flow Method for Computation of Bubble Cavitation Flows

2007 ◽  
Author(s):  
Guoyi Peng ◽  
Ryu Egashira ◽  
Takeru Yano ◽  
Shigeo Fujikawa
Keyword(s):  
High Speed ◽  
Two Phase Flow ◽  
Stokes Equations ◽  
Volume Fraction ◽  
Phase Flow ◽  
State Equations ◽  
Two Phase ◽  
Fluid Mixture ◽  
Local Flow ◽  
Flow Method

A pressure-based two-phase flow method is proposed for computation of high-speed cavitation flows by coupling a Two-Fluids Three-Pressure bubble dynamics model and a compressible two-phase flow computation. The fluid mixture of two-phase media is composed of a liquid and spherical gas bubbles, those are supposed to disperse in the liquid phase uniformly. State equations of the liquid and gas phases are employed to relate their density with pressure, and the flow of two-phase mixture is then calculated by employing Navier-Stokes equations. Cavitation is evaluated by the volume fraction of gas phase and the average radius of cavitation bubbles in a local flow field is calculated by applying Rayleigh-Plesset equation. For simultaneous computation of above equations, a pressure-based predictor-corrector procedure is developed by applying CCUP method. As an example, flows in an orifice nozzle are treated and the reliability of computation is estimated by comparison with experimental data.

scholarly journals Experimental Study on Hydraulic Characteristics of Pneumatic Lifting Pump

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 388
Author(s):  
Juanli Zuo ◽  
Fengchao Li ◽  
Ning Zhang ◽  
Denghui He ◽  
Wen Wang ◽  
...  
Keyword(s):  
Theoretical Model ◽  
Flow Rate ◽  
Liquid Flow ◽  
High Speed ◽  
Two Phase Flow ◽  
Liquid Flow Rate ◽  
Bubble Formation ◽  
Phase Flow ◽  
Hydraulic Characteristics ◽  
Two Phase

A pneumatic lifting pump is used in sewage treatment, offshore oil production, and other fields because of its simple structure and strong practicability. In order to study its internal hydraulic characteristics and gas-liquid two-phase flow, this paper carries out experimental research on the influence of different air intake modes and riser diameters on the performance of a pneumatic lifting pump. The air-water two-phase flow pattern in the riser and motion characteristics of bubble formation at the nozzle are obtained by a high-speed camera. Through theoretical analysis, the theoretical model of a pneumatic lifting pump is established, and experimental results verify the theoretical model well. The results show that when the submergence ratio is constant, the lifting efficiency decreases with the smaller intake area under different intake areas; and the influences of different holes distributions on liquid flow rate and lifting efficiency are not significant under the same intake area. At the same submergence ratio, the smaller the riser diameter, the smaller the final lifting liquid flow rate and the larger the lifting efficiency peak value.

An Innovative Two-Phase Flow Pump and Separator Solution

2011 ◽  
Author(s):  
Franc¸ois Gruselle ◽  
Johan Steimes ◽  
Patrick Hendrick
Keyword(s):  
Flow Rate ◽  
Flow Model ◽  
Two Phase Flow ◽  
Volume Fraction ◽  
Operating Conditions ◽  
Liquid Volume ◽  
Phase Flow ◽  
Two Phase ◽  
Efficient System ◽  
Measurement Systems

The Aero-Thermo-Mechanics (ATM) department of Universite´ Libre de Bruxelles (ULB) develops a new system to simultaneously pump and separate a two-phase flow, in particular oil/air mixtures. Two-phase flows are encountered in many applications (oil extraction, flow in nuclear power plant pumps, pulp and paper processing) but the study is mainly focused on aeroengine lubrication systems. The main objective is to obtain a compact and efficient system that can both extract the gas of a two-phase flow and increase the pressure of the liquid phase. Particular care is given to the liquid flow rate lost at the gas outlet of the system. A large range of gas/liquid volume ratio has been studied, leading to different two-phase flow regimes at the inlet of the system (slug, churn or annular flow). After successful tests with water-air prototypes, which have allowed to identify the key design and working parameters, the technology has been implemented for a hot oil-air mixture. This paper presents the test results of the first oil/air prototype under real in-flight operating conditions. The tests with oil/air mixtures were performed on the aeroengine lubrication system test bench of the ATM department. The identification and implementation of appropriate two-phase flow rate measurement systems is an essential contribution to the project. Two attractive measurement systems have been considered: a Coriolis density meter for the volume fraction at the liquid outlet and radio-tracing elements for the measurement of the oil consumption at the air outlet. In parallel, the flow field in the pump and separator system has been studied with commercial CFD (Computational Fluid Dynamics) software packages. The choice of the two-phase flow model is highly dependent on the two-phase flow regime. But different regimes can simultaneously exist in the pump and separator system. So, the Eulerian two-phase flow model, the most complex and general model, seems to be the most appropriate. A coupling of this model with a dispersed phase model is under investigation to take all two-phase flow phenomena into account.

Model analysis for differential pressure two-phase flow rate meter in intermittent flow

2021 ◽  
pp. 102017
Author(s):  
S.P. Pellegrini ◽  
A.N. Wrasse ◽  
M.J. da Silva ◽  
R.E.M. Morales ◽  
F.C. Trigo ◽  
...  
Keyword(s):  
Flow Rate ◽  
Two Phase Flow ◽  
Model Analysis ◽  
Differential Pressure ◽  
Intermittent Flow ◽  
Phase Flow ◽  
Two Phase

Experimental investigation on the performance of a side channel pump under gas–liquid two-phase flow operating condition

2017 ◽  
Vol 231 (7) ◽  
pp. 645-653 ◽  
Author(s):  
Fan Zhang ◽  
Martin Böhle ◽  
Shouqi Yuan
Keyword(s):  
Two Phase Flow ◽  
Volume Fraction ◽  
Low Flow ◽  
Side Channel ◽  
Phase Flow ◽  
Vane Pump ◽  
Two Phase ◽  
Operating Condition ◽  
Gas Volume Fraction ◽  
Gas Volume

Side channel pump is a kind of small volume vane pump with low flow rate but high head and most side channel pumps can transport gas–liquid two-phase flow. In order to investigate the performance of this type of pump depending on the blade suction angle under gas–liquid two-phase flow operating condition, an experimental study has been carried out. The head and efficiency curves, and the influence of blade suction angle changes on these curves for different inlet gas volume fraction states are analyzed in detail. Moreover, the gas transporting capability of the impeller with three different blade suction angles (10°, 20°, 30°) are also compared. The results show that the head and efficiency performances of the three impellers decrease a large value when the side channel pump operates with a little gas inside, and the operating range narrows as well. With the increasing of inlet gas volume fraction, the performance of the side channel pump worsens. The head and efficiency performances in the single-phase state improve by increasing the blade suction angle, but decrease by increasing the blade suction angle in the gas–liquid two-phase flow state. The maximum gas transporting capability of the impeller with a small blade suction angle is better than a large blade suction angle. Analysis on the measured data allows a better understanding of the effect of inlet gas quantity on the performance of the side channel pump with different blade suction angles, and it could supply the design reference for two-phase flow side channel pumps.

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