Effects of Two-Phase Flow Friction Factor Correlations on the Optimal Pressure Drop-Martinelli Parameter Pair in a Mini-Channel

2016 ◽  
Vol 819 ◽  
pp. 309-313
Author(s):  
Normah Mohd Ghazali ◽  
Agus Sunjarianto Pamitran ◽  
Oh Jong-Taek ◽  
Robiah Ahmad ◽  
Muhammad Khairul Fitkry Rabin

Substantial research has been completed with more on-going on the flow pattern and heat transfer associated with two-phase flows. Discrepancies reported may have been as much as agreements, due to the different models, approaches, flow regimes, correlations, and new working fluids being utilized. This paper reports the outcome of a study to look at the effects of applying two different friction factor correlations on the simultaneous minimization of the pressure drop and Martinelli parameter under optimized flow rate and vapor quality, using genetic algorithm. The homogeneous model is assumed with ammonia as the working fluid, the coolant being environmentally friendly and having recently discovered as a potential replacement for the current refrigerants in micro and mini-channels. Results show that significant differences in the frictional pressure drop and Martinelli parameter arise due to the different correlations used, and this is only the outcome from two different correlations currently being considered by researchers in pressure drop analysis for two-phase flows in mini-channels. Thus, absolute agreement is indeed not possible between theoretical, experimental, and numerical work in view of the many different available correlations being utilized today with differences between 10 to 100 percent that has already been established.

2019 ◽  
Vol 27 (04) ◽  
pp. 1950037
Author(s):  
Qais Abid Yousif ◽  
Normah Mohd-Ghazali ◽  
Agus Sunjarianto Pamitran ◽  
Yushazaziah Mohd-Yunos

Accurate prediction of the friction factor and consequently the pressure drop of two-phase flow in small channels is still an issue. Many correlations exist for the determination of the viscosity and the friction factor that appear in the frictional pressure drop and their combination often determined the degree of disagreements between the experimental data and predicted outcomes. Demands for environmentally friendly refrigerants have further posed a challenge to find compatible alternatives with as good a performance as the current coolants. Despite the many available correlations developed to date, many more are studied in effort to reduce the discrepancies. This paper presents the outcomes of a study comparing the optimized conditions when three different viscosity equations are paired with eight different friction factor correlations to minimize the frictional pressure drop. The approach used multi-objective genetic algorithm (MOGA) to assist in selecting the best pairing. Comparison is then completed with available experimental data. The study showed that the Blasius friction factor paired with the Dukler viscosity produced the least percentage difference for R22, while when paired with the McAdams viscosity produced a lower difference for R290, an environmentally friendly refrigerant being considered to replace R22.


Author(s):  
M. Hamayun Maqbool ◽  
Bjo¨rn Palm ◽  
R. Khodabandeh ◽  
Rashid Ali

Experiments have been performed to investigate two-phase pressure drop in a circular vertical mini-channel made of stainless steel (AISI 316) with internal diameter of 1.70 mm and a uniformly heated length of 245 mm using ammonia as working fluid. The experiments are conducted for heat flux range of 15 to 350 kW/m2 and mass flux range of 100 to 500 kg/m2s. A uniform heat flux is applied to the test section by DC power supply. Two phase frictional pressure drop variation with mass flux, vapour quality and heat flux was determined. The experimental results are compared to predictive methods available in literature for frictional pressure drop. The Homogeneous model and the correlation of Mu¨ller Steinhagen et al. [14] are in good agreement with our experimental data with MAD of 27% and 26% respectively.


Author(s):  
Akimaro Kawahara ◽  
Michio Sadatomi ◽  
Shinichi Miyagawa ◽  
Mohamed H. Mansour

In this paper, single-phase liquid and two-phase gas-liquid pressure drop data through 180° return bends have been obtained for horizontal rectangular micro-channel and mini-channel. To investigate the size effects of the test channels, the hydraulic diameters were 0.25 mm and 3 mm respectively as the micro-channel and the mini-channel. The curvature radii of the bends were 0.500 mm and 0.875 mm for the micro-channel, while 6 mm for the mini-channel. To know liquid properties effects, distilled water, surfactant and glycerin aqueous solutions, ethanol and HFE (hydrofluoroether)-7200 were used as the test liquid, while nitrogen gas and air as the test gas. Pressure distributions upstream and downstream tangents of the bend were measured for the single-phase and the two-phase flows. From the pressure distribution data, the bend pressure loss was determined. By analyzing the present data, the bend loss coefficient for single-phase flow in both micro- and mini-channels could be correlated with Dean number. On the other side, the total bend pressure loss for two-phase flows were correlated by using an approach of Padilla et al., in which the total pressure loss is the sum of two pressure drop components, i.e., frictional pressure drop and singular pressure drop. The approach was found to be applicable to the present data for the micro- and the mini-channels if the frictional pressure drop was calculated by Lockhart-Martinelli method with Mishima & Hibiki’s correlation and Kawahara et al.’s correlation and the singular pressure drop was calculated by a newly developed empirical correlation.


Author(s):  
Licheng Sun ◽  
Kaichiro Mishima

2092 data of two-phase flow pressure drop were collected from 18 published papers of which the working fluids include R123, R134a, R22, R236ea, R245fa, R404a, R407C, R410a, R507, CO2, water and air. The hydraulic diameter ranges from 0.506 to 12mm; Relo from 10 to 37000, and Rego from 3 to 4×105. 11 correlations and models for calculating the two-phase frictional pressure drop were evaluated based upon these data. The results show that the accuracy of the Lockhart-Martinelli method, Mishima and Hibiki correlation, Zhang and Mishima correlation and Lee and Mudawar correalion in the laminar region is very close to each other, while the Muller-Steinhagen and Heck correlation is the best among the evaluated correlations in the turbulent region. A modified Chisholm correlation was proposed, which is better than all of the evaluated correlations in the turbulent region and its mean relative error is about 29%. For refrigerants only, the new correlation and Muller-Steinhagen and Heck correlation are very close to each other and give better agreement than the other evaluated correlations.


2018 ◽  
Vol 332 ◽  
pp. 147-161 ◽  
Author(s):  
Cihang Lu ◽  
Ran Kong ◽  
Shouxu Qiao ◽  
Joshua Larimer ◽  
Seungjin Kim ◽  
...  

Author(s):  
Germano Scarabeli Custódio Assunção ◽  
Dykenlove Marcelin ◽  
João Carlos Von Hohendorff Filho ◽  
Denis José Schiozer ◽  
Marcelo Souza De Castro

Abstract Estimate pressure drop throughout petroleum production and transport system has an important role to properly sizing the various parameters involved in those complex facilities. One of the most challenging variables used to calculate the pressure drop is the friction factor, also known as Darcy–Weisbach’s friction factor. In this context, Colebrook’ s equation is recognized by many engineers and scientists as the most accurate equation to estimate it. However, due to its computational cost, since it is an implicit equation, several explicit equations have been developed over the decades to accurately estimate friction factor in a straightforward way. This paper aims to investigate accuracy of 46 of those explicit equations and Colebrook implicit equation against 2397 experimental points from single-phase and two-phase flows, with Reynolds number between 3000 and 735000 and relative roughness between 0 and 1.40 × 10−3. Applying three different statistical metrics, we concluded that the best explicit equation, proposed by Achour et al. (2002), presented better accuracy to estimate friction factor than Colebrook’s equation. On the other hand, we also showed that equations developed by Wood (1966), Rao and Kumar (2007) and Brkić (2016) must be used in specifics conditions which were developed, otherwise can produce highly inaccurate results. The remaining equations presented good accuracy and can be applied, however, presented similar or lower accuracy than Colebrook’s equation.


Author(s):  
Yuqing Xue ◽  
Huixiong Li ◽  
Tianyou Sheng ◽  
Changjiang Liao

A large amount of air need be transported into the reservoir in the deep stratum to supply oxygen to some microbes in Microbial Enhanced Oil Recovery (MEOR). Air-water two-phase flows downward along vertical pipeline during the air transportation. Base on the experiment data described in this paper, the characteristics of air-water two phase flow patterns were investigated. The flow pattern map of air-water two phase flows in the pipe with inner diameter of 65 mm was drawn, criterions of flow pattern transition were discussed, and the dynamic signals of the pressure and the differential pressure of the two phase flow were recorded to characterize the three basic flow regimes indirectly. The frictional pressure drop of downward flow in vertical pipe must not be disregarded contrast with upward two phase flow in the vertical pipe because the buoyancy must be overcame when the gas flows downward along pipe, and there would be a maximum value of frictional when the flow pattern translated from slug flow to churn flow.


Author(s):  
Hideo Ide ◽  
Tohru Fukano

Both vertical upward and horizontal gas-liquid two-phase flows in a flat capillary rectangular channel were studied to clarify the flow phenomena, the holdup and the frictional pressure drop. The dimension of the channel used was 9.9 mm × 1.1 mm. The orientations of the channel were with the wide side vertical and the wide side horizontal. The differences between the flow characteristics in such orientations were investigated. New correlations of holdup and frictional pressure drop for flat capillary channels are proposed, in which the effect of aspect ratio has been taken into consideration.


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