5. Corresponding authors, a However, the penalty in friction factor and pressure drop is 17.28% and 14.24% under the same Reynolds number and 1.0vol% nanofluid over the base fluid. If you want to reproduce the whole article At 1.0vol%, the thermal conductivity enhancements of 12.7% and 22.8%, at 1.0vol%, the viscosity enhancements of 1.57-times and 1.8-times were observed at temperatures of 293K and 333K compared to water data. For 1.0% vol. The authors would like to acknowledge the Portuguese Science and Technology Foundation (FCT) for the funding of the present research work through the grant no: PTDC/EME-MFE/105031/2008 (ACMS) and UID/EMS/00481/2013 (TEMA/DEM). Sundar et al. Electrical Conductivity and Dielectric Properties An estimation of the optimal supplied energy and time for sonication was suggested, while temperature and volumetric concentration effects on thermal conductivity are evaluated by measurements. Because dissolved salts and other inorganic chemicals conduct electrical current, conductivity increases as salinity increases. It has been shown that water is the best solar energy absorbance among four fluids including water, ethylene glycol, propylene glycol, Zeta potential is a measure of the electric potential difference between the surface of a particle and the surrounding fluid. Electrical conductivity measurements of nanofluids and - PubMed [27] prepared PG based Al2O3 nanofluids and estimated viscosity experimentally and proposed viscosity model. These plates are to be used in a proposed compact (thin and light-weight) solar thermal flat plate collector (FPC). This study investigates theoretically and experimentally the electrical and thermal conductivities of 50/50 water-ethylene glycol based TiO 2 nanofluids with nanoparticle concentrations in the range of 0.05-0.5 vol%. The effect of BNNB concentration in carrier fluids on nanofluid thermal conductivity was investigated by introducing BNNBs into ethylene glycol-water and propylene glycol-water mixtures at 010 wt%. The rheological behaviour is investigated through rotational rheometry. 0000087536 00000 n 0000125049 00000 n The formation of carboxyl (COOH) groups on the surface of ND particles was analyzed by FTIR spectrum. Comparisons with data from literature confirmed the validity and the suitability of the nanoflash technique applied to thermal conductivity evaluation. 0000089466 00000 n The ultra-sonication technique was employed for preparing the mixture and results showed that the stability and thermal conductivity enhancements of Al2O3H2O nanofluids are highly dependent on sonication time and the energy supplied to the fluid for its preparation. If you are an author contributing to an RSC publication, you do not need to request permission Under constant heat flux conditions, ZnOPG nanofluids exhibited linear increase in heat removal rates with increasing nanoparticle concentration. Group method of data handling (GMDH) and gene expression programming (GEP) as two white-box powerful models were used for modeling. Pressure and temperature variation of the electrical conductivity of endstream endobj 181 0 obj<. New thermal conductivity and viscosity correlations were proposed by including the effects of volume concentrations and temperatures. The stable PG/W mixture based ND nanofluids were prepared by dispersing ND acid treated, The nanodiamond (ND) particles were produced using commercially available ultra-dispersed diamond (UDD) powders. Results show, at 1.0vol% and the Reynolds number of 2702, the heat transfer coefficient and Nusselt number is increased by 36.05%, and 27.47%, respectively, over the base fluid. When compared to Propylene glycolwater (50:50) along with Propylene glycolwater (50:50) dispersed with 0.25% Graphene, it is clear from Fig. The thermal conductivity results here reported can be compared with those previously published by Sundar et al. Yeganeh et al. The results are beneficial for the design and operation of micro-channel absorber plates. The thermal performance of the internal heat transfer fluid was an important factor affecting the heat transfer efficiency of the exchanger system. The stability, thermophysical properties and rheological characteristics of N-CQDs nanofluids were investigated. 0000002234 00000 n E-mail: Forced convection experiments were performed on an instrumented metal plate with micro-channels. Nanodiamondwater nanofluids were prepared and estimated the thermal conductivity, viscosity and also estimated their potential use in heat transfer applications. 0000002868 00000 n Common uses: antifreeze/heat transfer fluid. The low freezing point of water (below 0C) may be achieved by adding different ratios of ethylene glycol or propylene glycol, so that the EG/W or PG/W fluid can operate up to 50C without any difficult [22]. 40-48, Applied Thermal Engineering, Volume 90, 2015, pp. to access the full features of the site or access our, Joint School of Nanoscience and Nanoengineering, North Carolina A&T State University, Greensboro, NC 27401, USA, Joint School of Nanoscience and Nanoengineering, University of North Carolina at Greensboro, Greensboro, NC 27401, USA. The density, isobaric heat capacity, and thermal conductivity of the nanofluids are determined by the oscillating U-tube, differential scanning calorimetry, and transient hot wire methods, respectively. At 1.0vol% of nanofluid and a Reynolds number of 1454.4 in comparison to the base fluid, the Nusselt number and heat transfer coefficient are boosted by 29.43%, 45.01%, and a friction factor penalty of 27.59%, respectively. Experimental research was done on the heat transfer, entropy generation, and exergy efficiency of ethylene glycol (EG) based nanodiamond (ND) nanofluids flowing in a circular tube. The article presents the results of detailed studies of the thermal conductivity of the water slurry of microencapsulated PCM (mPCM) and slurry based on waterpropylene glycol solutions. An enhancement of thermal conductivity with respect to temperature and volumetric concentration is found, as expected. 499-508, Energy Conversion and Management, Volume 96, 2015, pp. WebConductivity is a measure of the ability of water to pass an electrical current. Scaling effects such as viscous dissipation and entrance effects had insignificant impact on the measured average Nusselt number. 0000102258 00000 n The purchased UDD powders treated with strong acid treatment, dry salt and dry sucrose to make them into single ND-crystals. The earlier works reveal the preparation, estimation of thermal conductivity and viscosity of water, ethylene glycol, mineral oil and midel oil based ND nanofluids. Based on the results, the thermal conductivity enhancements are 18.8%, 16.8% and 14.1% at 1.0 vol.% of 20:80%, 40:60% and 60:40% PG/W based nanofluids. WebUsing the results for propylene glycol/water with corrosion inhibitor and nanoparticles, for over 3,000 hours of operation, the conductivity of the solution would have gone up to about 27 mS/cm-hr. In this work, mono B4C and TiB2 and hybrid TiB2:B4C nanoadditives are used for the first time to design nanofluids based on propylene glycol:water 20:80wt%. The single phase heat transfer fluids such as water (W), ethylene glycol (EG), propylene glycol (PG) and engine oil (EO) are primarily used in may industrial applications, among others, power, chemical and food industries. This paper investigates the significance of some micro scaling effects in micro-channel absorber plates. <50C [21]. The GMDH model showed a better performance compared to GEP, and could predict all data with an average absolute relative error of 2.27% in training and 2.44% in testing data set. trailer The local Nusselt number was observed to vary axially despite satisfying the criteria for neglecting entrance effects; this variation increased with the Graetz number. Among all the carbon materials ND particles creates great interest because of their superior hardness, thermal conductivity, i.e. [25], [26] also prepared 20:80%, 40:60% and 60:40% EG/W based Fe3O4 nanofluids and measured both thermal conductivity and viscosity experimentally. 0000003320 00000 n 0000000918 00000 n In this study, more than 3200 data of thermal conductivity of nanofluids were collected from literature to develop simple-to-use and accurate correlations for predicting relative thermal conductivity of nanofluids. conductivity Similarly, at 1.0vol% and Reynolds number of 2702, the thermal entropy generation is dropped by 38.12%, frictional entropy generation is raised by 12.86%, exergy efficiency is enhanced by 36.48% and thermal performance factor is augmented by 1.2094 times over the base fluid. The dataset includes 13 different nanofluids with temperature from 30.00 to 149.15C, particle size from 5.00 to 150.00nm, particle thermal conductivity from 1.20 to 1000.00W/mk, particle volume fractions from 0.01 to11.22%, and base fluid thermal conductivity from 0.11 to 0.69W/mk. The Choi [1] and his team developed nanofluids (fluids contain nanometer size particles) and obtained higher thermal conductivity compared to base fluids. 0000017674 00000 n WebDOWFROSTfluid is a formulation of 95.5 percent propylene glycol, dipotassium phosphate and water. Ghazvini et al. 0000002101 00000 n 0000086902 00000 n The exergy efficiency of the SCHE can be increased by 21% using 1.0vol% of nanofluid, but the improvement becomes modest as the volume concentration is increased further. please go to the Copyright Clearance Center request page. 0000115846 00000 n [12] also used acid mixtures of perchloric acid, nitric acid and hydrochloric acid (based on the procedure of Jang and Xu [13]) for the removal of carbon impurities from the UDD powders and prepared stable ND nanofluids in the base fluid of 55:45% ethylene glycol/water mixture and observed thermal conductivity enhancement of 18% at 2.0vol.%. jralston1@ncat.edu, b 0000073219 00000 n The carbon impurities present in the UDD powders have been removed using mixture of H2SO4 and HNO3 [5], [6], [7], [8], [9]. Due to its exceptional thermal, mechanical and electrical properties, diamond has attracted attention for use as a nanoparticle in fluids. The electrical conductivity of glycol mixtures within the range of 180 30 ScienceDirect is a registered trademark of Elsevier B.V. ScienceDirect is a registered trademark of Elsevier B.V. 2023, Thermal Science and Engineering Progress, 2023, International Journal of Thermal Sciences, 2022, International Communications in Heat and Mass Transfer, Diamond and Related Materials, Volume 69, 2016, pp. The Wilson plot method is used to analyze the helical coil side heat transfer coefficients. Due to the different particle sizes and shapes of nanoparticles, the proposed model can better predict the thermal conductivity and viscosity of N-CQDs nanofluids compared with other empirical models. From the Prasher et al. 0000003035 00000 n Reynolds numbers were in the range 10100 and fluid inlet temperatures ranged from 5 to 40C. 0000060250 00000 n WebThermal conductivities for some common liquids at temperature 300 K (26.8 oC, 80.3 oF): 1 W/(m K) = 1 W/(m oC) = 0.85984 kcal/(h m oC) = 0.5779 Btu/(ft h oF) = 0.048 Btu/(in h The preparation and properties of hybrid nanofluids containing diamond nanoparticles are analyzed and discussed in detail, and a list of potential uses for these enhanced heat transfer fluids in industrial and commercial applications is provided and deliberated. 0000086285 00000 n However, those results have not been collectively compared or discussed. [14,15] for mono nanofluids based on the same base fluid, propylene glycol:water 20:80 wt%. Please enable JavaScript Read more about how to correctly acknowledge RSC content. WebElectrical Conductivity ( S/cm) 55% Propylene Glycol + 45% DI Water + 0.1% Benzotriazole + 0.05% Nanoparticles (Mix# 2) 55% Propylene Glycol + 45% DI Water + 0.1% Benzotriazole + 0.025% Nanoparticles (Mix# 2) Electrical Conductivity vs. Time for the Coolant Formulations in a 1 L Dynamic Test Loop at 70oC 11 This study reports a nanofluid that achieves long-term stability without any additives. New thermal conductivity and viscosity correlations have been developed based on the experimental data. 0 of propylene glycol It is hygroscopic, meaning that it readily absorbs water from the surrounding environment. We use cookies to help provide and enhance our service and tailor content and ads. Vajjha and Das [24] also prepared 60:40% (weight ratio) of EG/W based Al2O3, CuO and ZnO nanofluids and measured thermal conductivity up to 10.0vol.%.

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