Figure - available from: International Journal of Photoenergy
This content is subject to copyright. Terms and conditions apply.
Source publication
In this research work, dimple texture tubes and silicon dioxide (SiO2) nanofluid were used to analyze the performance parameters of a solar water heater. For this purpose, SiO2 was mixed with deionized (DI) water using an ultrasonic dispersion device to prepare the nanofluids (SiO2/DI-H2O). The size of the nanoparticle was in the range of 10-15 nm....
Similar publications
Regarding the detrimental impacts of using non-renewable energy resources on the environment and the importance of increasing heat transfer in heat exchangers, this research is aimed to increase the heat transfer surface of the collector pipe in contact with the absorber plate at the flat-plate solar collector by designing the pipe in a zigzag shap...
Citations
... The statistics clearly show a growing trend in heat transfer, which is enhanced with Re and baffle angle orientations [36]. This augmentation in heat transfer was also noticed in all Re at varying concentrations. ...
... STFs have a great deal of potential in industries for integrating inside damper frameworks for optimizing their dynamic performance [9,10]. In addition, dimples inside tubes can be used to enhance heat transfer in various applications, including heat exchangers [11][12][13][14][15][16][17][18][19]; in some cases, STFs are used in heat exchangers or cooling systems to improve their efficiency. The combination of dimples and STFs can potentially lead to even better heat transfer performance due to the enhanced fluid mixing caused by dimples and the unique rheological properties of STFs. ...
Shear thickening fluids (STFs) have gained attention for their capacity to increase viscosity with higher shear rates, rendering them solid-like under high-impact conditions. This reversibility renders STFs valuable for diverse applications, particularly in defense systems. Preceding our study, mechanical hurdles, such as aggregation and blending issues, hindered efficient utilization. Our research presents an innovative method for STF synthesis using polyethylene glycol and SiO2 nanoparticles. Significantly, we employed a hot plate and oil bath to remove ethanol from the STF, a distinctive aspect of our approach. We also systematically explored the impact of temperature and the dispersion weight fraction of fumed silica nanoparticles on crucial rheological parameters, encompassing viscosity, shear rate, storage modulus (G′), and loss modulus (G″). As temperatures increased, the critical shear rate also rose, while viscosity decreased. Additionally, we observed a significant enhancement in thickening behavior with higher SiO2 concentrations in STFs. For instance, the peak viscosity of 15 wt% STF decreased by approximately 69.47% from 20 to 40 °C and by approximately 89.92% from 20 to 60 °C. This study highlights the unique rheological properties of STFs.
... The variables were constant heat flux (q"=1000 W/m 2 ), angle of teardrop, elliptical dimples (0 • and 45 • ), and turbulent flow regime (5000≤Re≤40,000). As a result, the best THP was obtained as 8 at Re=20,000 for pitch ratio of 2.5, elliptical angle of 45 • and dimple number of 6. Arun et al. [38,39] and Malapur et al. [40] conducted numerical studies to enhance the THP of solar collectors, and heat exchangers using DTs with spherical geometry. Firstly, Arun et al. [38] preferred SiO 2 /H 2 O as nanofluid along DT. ...
... As a result, the best THP was obtained as 8 at Re=20,000 for pitch ratio of 2.5, elliptical angle of 45 • and dimple number of 6. Arun et al. [38,39] and Malapur et al. [40] conducted numerical studies to enhance the THP of solar collectors, and heat exchangers using DTs with spherical geometry. Firstly, Arun et al. [38] preferred SiO 2 /H 2 O as nanofluid along DT. Then they studied experimentally and numerically for TiO 2 /H 2 O nanofluid flow under same boundary conditions. ...
In this paper, thermo-hydraulic performance and entropy generation of the sudden expansion tube with elliptical dimpled fins (DFs) at different directions was computationally performed at different Reynolds (Re) numbers ranging between 100≤Re≤2000 using cobalt ferrite/H2O (CoFe2O4/H2O) nanofluid (NF) (0.0≤φ≤ 2.0). The novelty of this study is to investigate the effect of the elliptical DF and its arrays in the sudden expansion tube in terms of thermodynamics laws (energy and entropy generations). While the sudden expansion ratio (D2/D1) is 2.5, elliptical dimple width (a) and height (b) show variations between 4 and 8 mm. In addition, the distances among elliptical DFs (P) are taken as P=10, 15, and 20 mm while the diameter (D1) and length (L1) of the inlet tube are D1=8 mm and L1=375 mm. The diameter (D2) and length (L2) of the tube with the sudden expanding and elliptical DFs are D2=20 mm and L2=1125 mm, respectively. The study comprehensively exhibits results of the thermo-hydraulic performance and entropy generation based on numerical data. The results demonstrated that the highest heat transfer rate is recorded by the case of DT3, and DT3 enhances the convective heat transfer rate by 221%, and increases the pressure drop by 17.38% at Re=2000 compared to smooth tube (ST). It was observed that as the Re increases, the performance evaluation criteria (PEC) gradually increases too, and the highest PEC has been obtained for DT3 as 2.11 at Re=2000. The entropy generation (EnG) was also evaluated in terms of both geometric designs and volumetric concentrations. Moreover, the best total EnG was found around 17% for DT3 at the Re=1000 and φ=2.0% compared to ST using H2O. Consequence of the applied analyses, the use of elliptic DFs in a sudden expansion tube enhances the convective heat transfer rate and decreases total EnG.
... indicates the unfilled pipe-based sun rays collector fitted, P r indicates the parabolic importunate, N indicates the hot water production system, and uDu indicates the combining end temperature fluids are given as, As presented in Eq. (3), dw indicates the proportion of temperature of the water, D initiates the terminal heat loss , R indicates the provided data, JB r indicates the heating efficiency, n r indicates the thermal mass flow rate, and R rj indicates the water intake temperature and water heat acquired (Arun et al. 2022c). The heat conduction platform is shown in Fig. 2. Solar water heating systems use heat exchangers to convert the solar energy collected in collectors into usable hot water. ...
A solar water heater has been developed to convert solar radiation into heat for use in residential and commercial settings. The collector makes up the bulk of a solar water heating system. The solar energy is captured by the collector and transferred to the tube that delivers the working fluid, water. In addition to the collector's tube, which carries the working fluid, researchers have focused on the design of the collector's tube. This paper examines the performance of a parabolic plate solar water heater that uses a copper dimpled tube with aluminum-coated tube channels. During the test, the flow rate of base fluid was in the range of 1.0 to 3.0 kg/min in steps of 0.5. The performance of the solar water heater was also evaluated and verified using CFD. The test data such as friction factor, Reynolds number, uncertainty analysis, Nusselt number, solar collector efficiency, coefficient of convective heat transfer, linear dimpled tube velocity analysis, achieving maximum energy efficiency and thermal efficiency have been used to generate parametric values for parabolic plate solar water heaters. The results suggest that the best outcomes can be achieved with a mass flow rate of 2.5 kg/min and the overall thermal efficiency was raised to 31.85%, which is 11% greater than that of the plain tube with base fluid. At mass flow rates of 2.5 kg/min, the pressure drop was found to be 6.24% higher than that of 3.0 kg/min. The experimental results were analyzed and compared with the CFD results, and the overall deviation was ± 3.24% which is in the acceptable range.
A solar collector is a device used to absorb energy from the sun by collecting solar radiation and turning it into electricity or heat. The material type and coating of a solar collector are utilized to enhance solar energy absorption. This research combines experimental and computational methods to examine the performance of a parabolic-type plate solar water heater (PTSWH). The nanoparticles-DI water at a rate of mass flow (MFR) of 0.5–3.0 kg/min in 0.5 kg/min increments were used in a tube-in-tube heat exchanger featuring dimpled inner tubes with a pressure-to-diameter (P/D) ratio of 3. The researchers examined the fluid flow patterns and heat transfer efficiency in a dimple texture tube using nanoparticles of TiO2, Al2O3, CuO, and SiO2 with a size range of 10–15 nm and a volume concentration (VC) of 0.1–0.5% in increments of 0.1%. Computational Fluid Dynamics (CFD) was used to explore and verify the impact of nanoparticle concentration on the PTSWH. It was revealed that CuO /DI-H2O at a nanoparticles VC of 0.3% and a MFR of 2.5 kg/min yielded the best PTSWH performance. With a nanoparticle concentration of 0.3% and MFR of 2.5 kg/min, the efficiency of PTSWH was increased by approximately 34.3% for TiO2, 32.3% for Al2O3, 38.4% for CuO, and 36.4% for SiO2. The results also show that the solar water heater’s thermal efficiency rose steadily with the rise in MFR. At a MFR of 2.5 kg/min, Cu/DI-H2O was found to have a higher Nusselt number than TiO2/DI-H2O, Al2O3/DI-H2O, and SiO2/DI-H2O, respectively, by 10.5%, 8.2%, and 5%. TiO2/DI-H2O, Al2O3/DI-H2O, Cu/DI-H2O, and SiO2/DI-H2O nanoparticle-coated dimple texturing tubes all had lower friction coefficients than a plain tube did. Finally, a comparison was made between the experimental and simulated data, and the overall variation of ± 3.1% was found to be within an acceptable range.
