For 1.0% vol. *
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. 0000047379 00000 n
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. [27] analysis if the value of C/Ck<4 then the nanofluid is heat transfer beneficial fluid. In the heat exchanger, the hot fluid passes through the shell side and the cold fluid (nanofluid) passes through the helical coil side. Islam, R.; Shabani, B. The findings suggest that BNNBs have great potential for use as thermally conductive nanoparticles in nanofluids for various heat transfer applications. Yeganeh et al. 0000003035 00000 n
They obtained increases of 10.4% and 9.9% for 0.5 vol% concentration of Fe3O4 [14] and 1 vol% concentration of nanodiamonds [15] at 293.15 K, respectively. The thermal performance of the internal heat transfer fluid was an important factor affecting the heat transfer efficiency of the exchanger system. The main advantages of this measurement technique are short measurement times, easy sample preparation and high accuracy. 40-48, Applied Thermal Engineering, Volume 90, 2015, pp. Download : Download high-res image (216KB)Download : Download full-size image. The local Nusselt number was observed to vary axially despite satisfying the criteria for neglecting entrance effects; this variation increased with the Graetz number. 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. 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. [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.%.
The present work shows an innovative frame saw machine to cut granite, the eccentric hinge guide mechanism is introduced into the machine. 0000002868 00000 n
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. and diagrams provided correct acknowledgement is given. This paper reviews and summarizes the experimental values of the physical and thermal properties, including an appropriate focus on the thermal conductivity enhancement, of nanodiamond-nanofluid systems found in the literature as well as different techniques for thermal conductivity measurement. 108-65-6) Dipropylene Glycol Methyl Ether (DPM; CAS No. The electrical conductivity of glycol mixtures within the range of 0000088556 00000 n
The stability, thermophysical properties and rheological characteristics of N-CQDs nanofluids were investigated. The thermal conductivity of single phase heat transfer fluids may be enhanced by dispersing small quantity of solid particles. 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). 0000086285 00000 n
Thermal conductivity of nanoparticle-fluid mixture. Nanofluids offer many opportunities to enhance the efficiency of thermal systems by improving the thermal properties of the host fluids. 0000088822 00000 n
Theoretical approach is used to identify the heat transfer benefits of the prepared propylene glycol/water based ND nanofluids in laminar and turbulent flow conditions using the, Portuguese Science and Technology Foundation, Investigations of thermal conductivity and viscosity of nanofluids, Viscosity of alumina nanoparticles dispersed in car engine coolant, Thermal conductivity of ethylene glycol and water mixture based Fe, Experimental determination of thermal conductivity of three nanofluids and development of new correlations, Numerical study of turbulent flow and heat transfer characteristics of nanofluids considering variable properties, Experimental investigation on the thermal transport properties of ethylene glycol based nanofluids containing low volume concentration diamond nanoparticles, Thermal transport properties of diamond-based nanofluids and nanocomposites, Volume fraction and temperature variations of the effective thermal conductivity of nanodiamond fluids in deionized water, Enhanced thermal properties of nanodiamond nanofluids, Increase of nanodiamond crystal size by selective oxidation, Experimental investigation of heat transfer and effectiveness of employing water and ethylene glycol mixture based Fe3O4 nanofluid in a shell and helical coil heat exchanger, Heat transfer and exergy efficiency analysis of 60% water and 40% ethylene glycol mixture diamond nanofluids flow through a shell and helical coil heat exchanger, Laminar convective heat transfer, entropy generation, and exergy efficiency studies on ethylene glycol based nanofluid containing nanodiamond nanoparticles, Experimental and modeling studies of N-doped carbon quantum dot nanofluids for heat transfer systems, Modeling thermal conductivity of nanofluids using advanced correlative approaches: Group method of data handling and gene expression programming, Thermophysical, rheological and electrical properties of mono and hybrid TiB2/B4C nanofluids based on a propylene glycol:water mixture, A new frame saw machine by diamond segmented blade for cutting granite, The significance of scaling effects in a solar absorber plate with micro-channels, Improved transient heat transfer performance of ZnOpropylene glycol nanofluids for energy management, Thermal conductivity and viscosity of water based nanodiamond (ND) nanofluids: An experimental study, Effect of temperature and sonication time on nanofluid thermal conductivity measurements by nano-flash method, Thermo-physical properties of diamond nanofluids: A review. The UDD powders can be treated with strong acids such as HNO3, mixture of H2SO4/HNO3, K2Cr2O7 in H2SO4, KOH/KNO3 to remove the carbon impurities [3], [4]. 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. Nanodiamond (ND) nanoparticles of primary particle size of 510nm can be produced in large quantity by using commercially available ultra-dispersed diamond (UDD) powders. The rheological behaviour is investigated through rotational rheometry. Chemical treatment was used to make ND nanoparticles with an average size of 5.42nm. WebPropylene Glycol Methyl Ether (PM; CAS No. The starting product, MICRONAL 5428 X, which contains about 43% microencapsulated paraffin with a transformation temperature of 28 0000115846 00000 n
Accurate estimation of thermal conductivity (TC) of nanofluids is essential in thermophysical studies of nanofluids. The reason for the agglomeration of UDD powders in the base fluid is due to the presence of carbon impurities. . WebLearn about the chemical and physical properties of Ethylene Glycol/water mixtures, on our blog. Under constant heat flux conditions, ZnOPG nanofluids exhibited linear increase in heat removal rates with increasing nanoparticle concentration.
[27] model and Mouromtseff number [31] is used to study the heat transfer benefits of PG/W based ND nanofluids in laminar and turbulent flow conditions. 0000003320 00000 n
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 purchased UDD powders treated with strong acid treatment, dry salt and dry sucrose to make them into single ND-crystals. BNNBs exhibit high thermal conductivity due to efficient phonon transfer and they are electrical insulators owing to their wide bandgap. 0000002101 00000 n
Check with Union Carbide or Dow as they manufacture glycols. I understand they do have a web site. Conjugate heat transfer was found to reduce the Nusselt number which agrees with the literature, this also resulted in a Peclet number dependent Nusselt number. 0000073219 00000 n
The commercially available ultra-dispersed diamond (UDD) powders of an average size of 0.12.0m have been used by Dolmatov [2] for the preparation of ND nanofluids, but he faced serious agglomeration problem with UDD powders in the base fluid. would like to thank FCT for his post-doctoral research grant: SFRH/BPD/79104/2011. There are different methods to purify the UDD powders. New thermal conductivity and viscosity correlations have been developed based on the experimental data. The X-ray powder diffraction (XRD), transmission, C, respectively compared to their respective base fluids. Prediction of electrical conductivity of TiO 2 water and ethylene glycol-based nanofluids for cooling application in low temperature PEM fuel cells. 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. The functional groups on the treated UDD powders were analyzed by FTIR. Among all the carbon materials ND particles creates great interest because of their superior hardness, thermal conductivity, i.e. 5. The sensitivity analysis illustrated that temperature has the highest effect on the relative TC followed by base fluid TC and particle volume fraction. 0000000016 00000 n
1000W/mK and Young's modulus, high electrical resistivity, attractive optical characteristics, and excellent chemical stability and biocompatibility. in a third-party publication (excluding your thesis/dissertation for which permission is not required)
On the other hand preparation of propylene glycol/water (PG/W) based nanofluids and estimation of thermal properties is also important before use in heat transfer equipments, because these PG/W fluids are also used as engine coolants for automobile radiators. A binary mixture of propylene glycol and water at 20:80 mass ratio offers protection against freezing up to 265.98 K [13], making it suitable as a heat transfer fluid To create stable nanofluids, the ND nanoparticles are ultrasonically agitated with EG for 4h. At a constant heat flux of q=9099W/m2, experiments were carried out in a laminar flow with Reynolds numbers ranging from 264.4 to 2194.4. The UDD powders contains large quantity of carbon impurities, which can be removed using strong acid treatment, dry salt and dry sucrose to make UDD powders into single ND particles. Correlations for the thermo-physical properties of the nanofluid were developed. WebBNNBs exhibit high thermal conductivity due to efficient phonon transfer and they are electrical insulators owing to their wide bandgap. 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%. 180 30
Kole and Dey [29] prepared 50:50% PG/W based Al2O3 nanofluids and observed nanofluids obey Newtonian behaviour in the measured temperature range from 10C to 50C. 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.
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This study investigates theoretically and experimentally the electrical and thermal conductivities of 50/50 water-ethylene glycol based TiO 2 nanofluids with Yu et al. The propylene glycol/water mixtures at different weight ratios were used as base fluids for the preparation of stable ND nanofluids. An investigation has been undertaken into the stone processing machines. I always eqip the system with a 2" hose connection with check valve so the contractor can use a pump to fill the system those glycol feeders The formation of carboxyl (COOH) groups on the surface of nanodiamond was analyzed by FTIR. Sundar et al. The Prasher et al. The fluid is colorless (water white). These plates are to be used in a proposed compact (thin and light-weight) solar thermal flat plate collector (FPC). The X-ray powder diffraction (XRD), transmission electron microscope (TEM) and Raman spectra was also performed on acid treated ND particles. Properties for Dowfrost (Propylene Glycol) Electrical conductivity for 50% at 25 deg C = 2,060 micromhos/cm and 249 micromhos/cm for 50% at 0 deg C. Looks provided correct acknowledgement is given. The theoretical models of Maxwell and Einstein have failed to estimate the thermal conductivity and viscosity of nanofluids as a function of temperature. The heat transfer capability of these single phase heat transfer fluids is limited because of its poor thermal conductivity. Sundar et al. model and the Mouromtseff number were used to study the heat transfer capability of ND nanofluid under laminar and turbulent flow conditions. The hybrid nanofluid presents intermediate values between those of the mono nanofluids for all the properties except dynamic viscosity.
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electrical conductivity of propylene glycol water mixture