Universal approach to predicting two-phase frictional pressure drop for mini/micro-channel saturated flow boiling

2013 ◽  
Vol 58 (1-2) ◽  
pp. 718-734 ◽  
Author(s):  
Sung-Min Kim ◽  
Issam Mudawar
Keyword(s):  
Pressure Drop ◽  
Flow Boiling ◽  
Micro Channel ◽  
Saturated Flow ◽  
Two Phase ◽  
Frictional Pressure Drop ◽  
Universal Approach

Two-phase pressure drop due to friction in micro-channel

2013 ◽  
Vol 228 (5) ◽  
pp. 921-931 ◽  
Author(s):  
Tae-Woo Lim ◽  
Sam-Sang You ◽  
Jong-Su Kim ◽  
Serng-Bae Moon ◽  
Dong-Hoan Seo
Keyword(s):  
Pressure Drop ◽  
Flow Boiling ◽  
Homogeneous Model ◽  
Absolute Error ◽  
Heat Fluxes ◽  
Micro Channel ◽  
Two Phase ◽  
Pressure Drops ◽  
Frictional Pressure Drop ◽  
New Correlation

This paper deals with an experimental investigation to measure the frictional pressure drops for two-phase flow boiling in a micro-channel with a hydraulic diameter of 500 µm. First, the experimental study is performed under the test conditions: heat fluxes ranging from 100 to 400 kW/m2, vapor qualities from 0 to 0.2, and mass fluxes of 200, 400 and 600 kg/m2s. Then, the frictional pressure drop during flow boiling is estimated using two models: the homogeneous model and the separated flow model. The experimental results show that the two-phase multiplier decreases with the increase of mass flux. In addition, the measured pressure drops are compared with those from a few correlation models available for macro-scales and mini/micro-scales. Finally, the present paper proposes a new correlation for two-phase frictional pressure drops in mini/micro-scales. This correlation model is developed based on the Chisholm constant C as a function of two-phase Reynolds and Weber numbers. It is found that the new correlation satisfactorily predicts the experimental data within mean absolute error (MAE) of 3.9%.

Two-Phase Flow and Heat Transfer in Rectangular Micro-Channels

2004 ◽  
Vol 126 (3) ◽  
pp. 288-300 ◽  
Author(s):  
Weilin Qu ◽  
Seok-Mann Yoon ◽  
Issam Mudawar
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Flow Pattern ◽  
Two Phase Flow ◽  
Flow Boiling ◽  
Flow Patterns ◽  
Heat Sinks ◽  
Phase Flow ◽  
Micro Channel ◽  
Two Phase

Knowledge of flow pattern and flow pattern transitions is essential to the development of reliable predictive tools for pressure drop and heat transfer in two-phase micro-channel heat sinks. In the present study, experiments were conducted with adiabatic nitrogen-water two-phase flow in a rectangular micro-channel having a 0.406×2.032mm2 cross-section. Superficial velocities of nitrogen and water ranged from 0.08 to 81.92 m/s and 0.04 to 10.24 m/s, respectively. Flow patterns were first identified using high-speed video imaging, and still photos were then taken for representative patterns. Results reveal the dominant flow patterns are slug and annular, with bubbly flow occurring only occasionally; stratified and churn flow were never observed. A flow pattern map was constructed and compared with previous maps and predictions of flow pattern transition models. Features unique to two-phase micro-channel flow were identified and employed to validate key assumptions of an annular flow boiling model that was previously developed to predict pressure drop and heat transfer in two-phase micro-channel heat sinks. This earlier model was modified based on new findings from the adiabatic two-phase flow study. The modified model shows good agreement with experimental data for water-cooled heat sinks.

Flow boiling in horizontal flattened tubes: Part I – Two-phase frictional pressure drop results and model

2009 ◽  
Vol 52 (15-16) ◽  
pp. 3634-3644 ◽  
Author(s):  
Jesús Moreno Quibén ◽  
Lixin Cheng ◽  
Ricardo J. da Silva Lima ◽  
John R. Thome
Keyword(s):  
Pressure Drop ◽  
Flow Boiling ◽  
Two Phase ◽  
Frictional Pressure Drop

PRESSURE DROP CHARACTERISTICS OF R410A-OIL MIXTURE FLOW BOILING IN SMALL SMOOTH TUBES

2010 ◽  
Vol 18 (02) ◽  
pp. 109-116 ◽  
Author(s):  
YIFENG GAO ◽  
BIN DENG ◽  
GUOLIANG DING ◽  
HAITAO HU ◽  
XIANGCHAO HUANG
Keyword(s):  
Pressure Drop ◽  
Flow Boiling ◽  
Smooth Tube ◽  
Two Phase ◽  
Experimental Conditions ◽  
Mixture Flow ◽  
Frictional Pressure Drop ◽  
New Correlation ◽  
Smooth Tubes ◽  
Local Properties

This study presents experimental frictional pressure drop for R410A/oil mixture flow boiling in small horizontal smooth tubes with inside diameters of 4.18 mm and 2.0 mm. Experimental conditions cover nominal oil concentrations from 0 to 5%. The test results show that the presence of oil enhances two-phase frictional pressure drop about 0–120% and 0–90% at present test conditions for 4.18 mm I.D. smooth tube and 2.0 mm I.D. smooth tube, respectively, and the enhanced effect is more evident at higher vapor qualities where the local oil concentrations are higher. A new correlation to predict the local frictional pressure drop of R410A/oil mixture flow boiling inside conventional size and small smooth tubes is developed based on local properties of refrigerant–oil mixture, and the experimental data of 4.18 mm I.D. and 2.0 mm I.D. smooth tubes and that of 6.34 mm I.D. smooth tube (Hu et al., 2008) are well-correlated with the new correlation.

Experimental Investigation of Flow Boiling Pressure Drop of R134A in a Microscale Horizontal Smooth Tube

2011 ◽  
Vol 3 (1) ◽  
Author(s):  
Cristiano Bigonha Tibiriçá ◽  
Jaqueline Diniz da Silva ◽  
Gherhardt Ribatski
Keyword(s):  
Pressure Drop ◽  
High Speed ◽  
Flow Boiling ◽  
Smooth Tube ◽  
Working Fluid ◽  
Prediction Methods ◽  
Internal Diameter ◽  
Two Phase ◽  
Pressure Drops ◽  
Frictional Pressure Drop

This paper presents new experimental flow boiling pressure drop results in a microscale tube. The experimental data were obtained under diabatic conditions in a horizontal smooth tube with an internal diameter of 2.32 mm. Experiments were performed with R134a as working fluid, mass velocities ranging from 100 kg/m2 s to 600 kg/m2 s, heat flux ranging from 10 kW/m2 to 55 kW/m2, saturation temperatures of 31°C, and exit vapor qualities from 0.20 to 0.99. Flow pattern characterization was also performed from images obtained by high-speed filming. Pressure drop gradients up to 48 kPa/m were measured. These data were carefully analyzed and compared against 13 two-phase frictional pressure drop prediction methods, including both macro- and microscale methods. Comparisons against these methods based on the data segregated according to flow patterns were also performed. Overall, the method by Cioncolini et al. (2009, “Unified Macro-to-Microscale Method to Predict Two-Phase Frictional Pressure Drops of Annular Flows,” Int. J. Multiphase Flow, 35, pp. 1138–1148) provided quite accurate predictions of the present database.

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