Experimental Investigation of Friction Reduction in Transport of Fluids Using Surfactants

Author(s):  
Florencio Sanchez-Silva ◽  
Ignacio Carvajal-Mariscal ◽  
Pedro Quinto-Diez ◽  
Juan Gabriel Barbosa-Saldana

This paper presents the results of the influence of surfactants in reducing friction while driving fluid in pipes. Experimental research was conducted with water-surfactant mixtures which were tested three types of these additives: anionic, cationic and nonionic surfactants. Was designed and built an experimental facility in which the test area was acrylic pipe with an inner diameter of D = 19 mm and a length of 300 D. The concentrations of surfactants in the mixtures were 150, 250, 500, 750 and 1000 ppm, added according to a pilot program that took into account the amount and type of additive added in different liquid mass fluxes. Pressure losses were compared against those obtained when flow is the same water flows through the installation. The results obtained show a reduction of up to 43.9% of the friction which is achieved with a Re = 11243 and surfactant concentrations of 250 ppm (cetyl trimethyl chloride ammonium), to which was added as a stabilizer for the micro structure of the surfactant, sodium salicylate, which applies only to the cationic type surfactants. The results are promising but left to study such issues as: the injection and recovery of surfactant, more efficient mixing, the mechanisms that lead to a reduction of friction and the effect of temperature among others.

Author(s):  
John Wesley Coleman

This paper presents the results of an experimental investigation of two-phase pressure loss of R134a in microchannel headers using various end-cut techniques. Novel experimental techniques and test sections were developed to enable the accurate determination of the minor losses without obfuscating the problem with a lengthwise pressure gradient. This technique represents a departure from approaches used by other investigators that have extrapolated minor losses from air-water experiments and the combined effects of expansion, contraction, deceleration, and lengthwise pressure gradients. Pressure losses were recorded over the entire range of qualities from 100% vapor to 100% liquid. In addition, the tests were conducted for five different refrigerant mass fluxes between 185 kg/m2-s and 785 kg/m2-s using two differnt end-cut techniques. More than 790 data points were recorded to obtain a comprehensive understanding of the effects of mass flux and quality on minor pressure losses. High accuracy instrumentation such as coriolis mass flowmeters, RTDs, pressure transducers, and real-time data analyses were used to ensure accuracy in the results. The results show that many of the commonly used correlations for estimating two-phase pressure losses significantly underpredict the pressure losses found in compact microchannel tube headers. Furthermore, the results show that the end-cut technique can substantially affect the pressure losses in microchannel headers. A new model for estimating the pressure loss in microchannel headers is presented and a comparison of the end-cut techniques on the minor losses is reported.


2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
Alejandro I. Lazarte ◽  
William Fullmer ◽  
Martín Bertodano

This paper presents an experimental validation of RELAP5 and TRACE5 for licensing studies of the Atucha II-PHWR nuclear power plant. A scaled experimental facility, representing the boron injection system of Atucha II, was built. The system has a fundamental importance for loss of coolant accidents (LOCA) and anticipated transients without scram (ATWS). The experiment consists of the discharge of a tank that represents the boron tank filled with air or a mixture of air-water onto a discharge tank that represents the moderator tank. Both tanks are connected by a pipe which includes a valve and an orifice plate to model the pressure losses due to the fittings in the real system. The pressure and water level measured in the tanks are compared with the RELAP5 and TRACE5 predictions. The codes predict the pressure in the tanks accurately. However, both codes overpredict the heat transfer in the boron tank air-water interface which produces a greater expansion of the air which leads to a small discrepancy in the boron tank level prediction.


Author(s):  
K. H. Kang ◽  
R. J. Park ◽  
K. M. Koo ◽  
S. B. Kim ◽  
H. D. Kim

Feasibility experiments were performed for the assessment of improved In-Vessel Corium Retention (IVR) concepts using an internal engineered gap device and also a dual strategy of In/Ex-vessel cooling using the LAVA experimental facility. The internal engineered gap device made of carbon steel was installed inside the LAVA lower head vessel and it made a uniform gap with the vessel by 10 mm. In/Ex-vessel cooling in the dual strategy experiment was performed installing an external guide vessel outside the LAVA lower head vessel at a uniform gap of 25 mm. The LAVA lower head vessel was a hemispherical test vessel simulated with a 1/8 linear scale mock-up of the reactor vessel lower plenum with an inner diameter of 500 mm and thickness of 25 mm. In both of the tests, Al2O3 melt was delivered into about 50K subcooled water inside the lower head vessel under the elevated pressure. Temperatures of the internal engineered gap device and the lower head vessel were measured by K-type thermocouples embedded radially in the 3mm depth of the lower head vessel outer surface and in the 4mm depth of the internal engineered gap device, respectively. In the dual strategy experiment, the Ex-vessel cooling featured pool boiling in the gap between the lower head vessel and the external guide vessel. It could be found from the experimental results that the internal engineered gap device was intact and so the vessel experienced little thermal and mechanical attacks in the internal engineered gap device experiment. And also the vessel was effectively cooled via mutual boiling heat removal in- and ex-vessel in the dual strategy experiment. Compared with the previous LAVA experimental results performed for the investigation of the inherent in-vessel gap cooling, it could be confirmed that the Ex-vessel cooling measure was dominant over the In-vessel cooling measure in this study. It is concluded that the improved cooling measures using a internal engineered gap device and a dual strategy promote the cooling characteristics of the lower head vessel and so enhance the integrity of the vessel in the end.


2019 ◽  
Vol 964 ◽  
pp. 280-285
Author(s):  
Dian Mughni Fellicia ◽  
Rochiem Rochman ◽  
Clarissa Changraini

Good electrical conductivity properties of aluminium are the main reason this metal become an option as material of electrical devices. To improve the ductility and electrical conductivity properties, aluminium is combined with copper. The aim of this study is to analyze the effect of temperature and holding time of full-annealing heat treatment to the micro structure, hardness, and electrical conductivity of aluminium copper alloy (Al-Cu). In this research, pure aluminium with the addition of 4% copper (Cu) composition has been casted with gravity die casting mold made from ductile cast iron, and continued full-annealing heat treatment with 3 variations at temperature (2600C, 3500C, and 4400C), and 3 variations of holding time (2 hours, 3 hours, and 4 hours). It was found that the effect of higher temperature at the same holding time with the full-annealing heat treatment caused the grains of phase α become more regular and greater so that the hardness decreased and the electrical conductivity was increased.


2016 ◽  
Vol 819 ◽  
pp. 94-100
Author(s):  
Pham Quang Vu ◽  
Nguyen Ba Chien ◽  
Oh Jong Taek

Condensation heat transfer has been evaluated experimentally on the tube side of three different circular tubes with inner diameter of 6.2, 7.5 and 9.2mm, respectively. Two-phase fluid flow conditions include mass fluxes from 200 to 320kg/m2s, qualities between 0.1 to 0.9, and heat flus range of 5 to 20kW/m2 at a fixed saturation temperature of 48°C. Results showed that the average heat transfer coefficient increased with the increase of vapor quality, mass flux and heat flux, but decreased with inner diameter. The experiment results are compared with the existing heat transfer coefficient correlations, and a new correlation is developed with good prediction.


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