scholarly journals Venturi Wet Gas Flow Modeling Based on Homogeneous and Separated Flow Theory

2008 ◽  
Vol 2008 ◽  
pp. 1-25 ◽  
Author(s):  
Fang Lide ◽  
Zhang Tao ◽  
Xu Ying
Keyword(s):  
High Pressure ◽  
Pressure Drop ◽  
Gas Flow ◽  
Flow Model ◽  
Separated Flow ◽  
Flow Theory ◽  
Low Pressure ◽  
New Correlation ◽  
Wet Gas ◽  
Low Pressures

When Venturi meters are used in wet gas, the measured differential pressure is higher than it would be in gas phases flowing alone. This phenomenon is called over-reading. Eight famous over-reading correlations have been studied by many researchers under low- and high-pressure conditions, the conclusion is separated flow model and homogeneous flow model performing well both under high and low pressures. In this study, a new metering method is presented based on homogeneous and separated flow theory; the acceleration pressure drop and the friction pressure drop of Venturi under two-phase flow conditions are considered in new correlation, and its validity is verified through experiment. For low pressure, a new test program has been implemented in Tianjin University’s low-pressure wet gas loop. For high pressure, the National Engineering Laboratory offered their reports on the web, so the coefficients of the new proposed correlation are fitted with all independent data both under high and low pressures. Finally, the applicability and errors of new correlation are analyzed.

A new correlation of wet gas flow for low pressure with a vertically mounted Venturi meter

2019 ◽  
Vol 70 ◽  
pp. 101636
Author(s):  
Yanzhi Pan ◽  
Yi Hong ◽  
Qin Sun ◽  
Ziqiong Zheng ◽  
Dong Wang ◽  
...  
Keyword(s):  
Gas Flow ◽  
Low Pressure ◽  
New Correlation ◽  
Wet Gas

scholarly journals Experimental Investigation and Prediction on Pressure Drop during Flow Boiling in Horizontal Microchannels

Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 510
Author(s):  
Yan Huang ◽  
Bifen Shu ◽  
Shengnan Zhou ◽  
Qi Shi
Keyword(s):  
Pressure Drop ◽  
Flow Model ◽  
Two Phase Flow ◽  
Flow Boiling ◽  
Separated Flow ◽  
Heat Fluxes ◽  
Phase Flow ◽  
Vapor Quality ◽  
Two Phase ◽  
Gas Flux

In this paper, two-phase pressure drop data were obtained for boiling in horizontal rectangular microchannels with a hydraulic diameter of 0.55 mm for R-134a over mass velocities from 790 to 1122, heat fluxes from 0 to 31.08 kW/m2 and vapor qualities from 0 to 0.25. The experimental results show that the Chisholm parameter in the separated flow model relies heavily on the vapor quality, especially in the low vapor quality region (from 0 to 0.1), where the two-phase flow pattern is mainly bubbly and slug flow. Then, the measured pressure drop data are compared with those from six separated flow models. Based on the comparison result, the superficial gas flux is introduced in this paper to consider the comprehensive influence of mass velocity and vapor quality on two-phase flow pressure drop, and a new equation for the Chisholm parameter in the separated flow model is proposed as a function of the superficial gas flux . The mean absolute error (MAE ) of the new flow correlation is 16.82%, which is significantly lower than the other correlations. Moreover, the applicability of the new expression has been verified by the experimental data in other literatures.

Evaluation of Two-Phase Frictional Pressure Drop Correlations Against Experimental Data

2019 ◽  
Vol 12 (3) ◽  
Author(s):  
Wei Li ◽  
Kunrong Shen ◽  
Boren Zheng ◽  
Xiang Ma ◽  
S. A. Sherif ◽  
...  
Keyword(s):  
Experimental Data ◽  
Pressure Drop ◽  
Mass Flow ◽  
Flow Model ◽  
Saturation Temperature ◽  
Separated Flow ◽  
Outer Diameter ◽  
Two Phase ◽  
Homogeneous Flow ◽  
Frictional Pressure Drop

Abstract Results are presented here from an experimental investigation on tube side two-phase characteristics that took place in four tested tubes—the 1EHT-1, 1EHT-2, 4LB, and smooth tubes. The equivalent outer diameter of the tube was 9.52 mm and the inner diameter was 8.32 mm. Condensation tests were conducted using refrigerant R410A at a saturation temperature of 318 K, over a mass flow range of 150–450 kg m−2 s−1, with inlet and outlet vapor qualities of 0.8 and 0.2, respectively. Evaporation tests were performed at a saturation temperature of 279 K, over a mass flow range of 150–380 kg m−2 s−1, with inlet and outlet vapor qualities of 0.2 and 0.8, respectively. Pressure drop data of the four tested tubes were collected to evaluate five identified prediction correlations based on the separated flow model and the homogeneous flow model. The separated flow approaches presented predictions with average MAEs of 24.9% and 16.4% for condensation and evaporation data, respectively, while the average MAEs of the homogeneous flow model were 31.6% and 43.4%, respectively. Almost all the identified correlations underestimated the frictional pressure drop of the 4LB tube with MAEs exceeding 30%. An earlier transition of different flow patterns was expected to occur in the EHT tubes while developing a new diabatic flow pattern map is needed for the 4LB tube. A new correlation was presented based on the two-phase multiplier Φ and the Martinelli parameter Xtt, which exhibited excellent predictive results for the experimental data.

Evaluation of Existing Frictional Pressure Drop Correlations During Condensation of R410A in Four Horizontal Tubes

2019 ◽  
Author(s):  
Kunrong Shen ◽  
Zhichuan Sun ◽  
Wei Li ◽  
Xiang Ma ◽  
Yan He ◽  
...  
Keyword(s):  
Experimental Data ◽  
Pressure Drop ◽  
Flow Model ◽  
Saturation Temperature ◽  
Separated Flow ◽  
Smooth Tube ◽  
Outer Diameter ◽  
Homogeneous Flow ◽  
Frictional Pressure Drop ◽  
Horizontal Tubes

Abstract Results are presented here from an experimental investigation on tube side condensation characteristics that took place in four tested tubes — 1EHT-1, 1EHT-2, 4LB and a smooth tube. The equivalent outer diameter of the tubes was 9.52 mm and the inner diameter was 8.32 mm. Condensation tests were conducted using refrigerant R410A at a saturation temperature of 318K, over a mass flow range of 150–450 kgm−2s−1, with inlet and outlet vapor quality of 0.8 and 0.2, respectively. Pressure drop data of the four tested tubes were collected to evaluate five identified prediction correlations based on the separated flow model and the homogeneous flow model. For 1EHT-2 and the smooth tube, all the listed correlations manage to present predictions with the Mean Absolute Relative Deviation (MARD) less than 30%, while they underestimate the frictional pressure drop of the 4LB tube with MARD exceeding 40% averagely. Regarding the experimental data, it is found that the Muller-Steinhagen and Heck correlation presents the most accurate and stable prediction for the 4 tested tubes. The listed homogeneous flow correlations can provide acceptable predictions with MARD ranging from 25% to 40% under a few conditions, but their average predictive accuracies are inferior to that of the separated flow correlations. Consequently, the separated flow approach performs better than the homogeneous flow model in the prediction of frictional pressure drop for our experimental data.

Some Numerical Simulations and an Experimental Investigation of a Finger Seal

2005 ◽  
Author(s):  
Minel J. Braun ◽  
Hazel M. Pierson ◽  
Hongmin Li
Keyword(s):  
Experimental Investigation ◽  
High Pressure ◽  
Pressure Drop ◽  
Numerical Simulations ◽  
Mechanical Performance ◽  
Low Pressure ◽  
Pressure Differential ◽  
Experimental Results ◽  
Axial Pressure ◽  
Brush Seals

Finger seals (FS) are compliant seal configurations. Unlike brush seals, they exhibit hydrodynamic lifting capabilities which allow non-contact sealing between stationary and rotating members. The compliance combined with the non-contacting feature allows both axial and radial adjustment of the seal to the rotor excursions without endangering the integrity of the former. The embodiment of a two-layer finger seal with high pressure (1c) and low pressure (1b) laminates is shown in Figure1. In this paper we shall analyze the thermo-hydraulic and mechanical performance (axial and radial deformations and displacements) of a representative repetitive cell that contains four high pressure and four low-pressure fingers arranged axially in a staggered configuration, and subject to rotation and an axial pressure drop. We shall also present experimental results pertaining to the seal deformation under axial pressure differential and rotation.

Investigation on the swirlmeter performance in low pressure wet gas flow

Measurement ◽  
2011 ◽  
Vol 44 (5) ◽  
pp. 881-887 ◽  
Author(s):  
Chenquan Hua ◽  
Yanfeng Geng
Keyword(s):  
Gas Flow ◽  
Low Pressure ◽  
Wet Gas
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