Thermo-hydraulic Performance Analysis of Al2O3/water Nanofluid Flow in a Tube Extended by Twisted Tape

Abstract

In this numerical study, heat transfer characteristics and hydrodynamical analysis have been performed for a circular tube inserted with twisted tape, which has different twisted pitch ratios (TPR=0, 50, 100, and 200). As a working fluid Al2O3/water nanofluid is used which has different volumetric concentrations (0.0≤φ≤3.0 vol. %). The numerical analysis has been carried out under the constant wall heat flux (q′′) of 4357 W/m2 for laminar flow ranging the Reynolds (Re) number from 1000 to 2000. According to numerical results, the highest average Nusselt number (Nu) and average Darcy friction factor (ff) have realized in twisted pitch ratio (TPR) 50. The reason is that when the twisted pitch ratio gradually decreases, stronger secondary flows and a higher velocity can be obtained. When compared with water, the highest Nu for TPR=50 has been obtained at φ=3.0 vol. % concentration as 61.15%. Also, when compared with TPR=0, the highest thermal performance enhancement (TPE) was realized at φ=3.0 vol. % concentration and Re=2000 conditions as 61.15% for TPR=50. Keywords: CFD Convective heat transfer Laminar flow Al2O3/water Twisted tape

Investigation of magneto-convection characteristics in a sudden expanding channel with convex surface geometry under thermally developing flow conditions

“…The passive technique (Mousavi Ajarostaghi et al, 2022) provides an increase in the heat transfer by making structural changes such as addition of the extra equipment and using different heat transfer fluids. Researchers have generally focused on lots of ways such as twisted tapes (Gürsoy et al, 2022a(Gürsoy et al, , 2022b, baffles (El-Said et al, 2021), winglets (Promvonge et al, 2021), extended surfaces (Zaboli et al, 2021), porous materials (Chakravarty et al, 2021), coil inserts (Dinh et al, 2022), rough surfaces (Gürsoy et al, 2023), mono, hybrid and ternary nanofluids (Dezfulizadeh et al, 2022;Said et al, 2022;Sirine et al, 2022). For instance, rough surface, which includes dimpled fins (DFs), is one of the prominent passive techniques in the geometric improvement, and this phenomenon has been investigated by numerous researchers in the literature (Gürdal et al, 2022a(Gürdal et al, , 2022b(Gürdal et al, , 2022cSuri et al, 2022; Magnetoconvection characteristics Malapur et al, 2023) conducted a computational analyse on five different dimpled tubes (DT).…”

“…In fact, NFs have been examined together with DF in both experimental and numerical studies in the literature. Gürsoy et al (2022aGürsoy et al ( , 2022b theoretically analysed the THP of ferrofluid (FF) in a sudden expansion tube (SET) retrofitted with DF. The analyses have been performed under 100 # Re # 2000, q 00 ¼ 600 W/m 2 , and 1.0% # w # 2.0%.…”

“…This determined purpose reveals the novelty of this study. Based on this situation, the flow geometry in which the best PEC has been obtained in the study (ER ¼ 2.5 and P/d ¼ 3.0) conducted by Gürsoy et al (2022aGürsoy et al ( , 2022b has been used for this investigation. It has numerically been handled in this study as the fundamental flow problem, and the effect of MF on the SET filled with FF has been examined in detail.…”

“…, 2022) provides an increase in the heat transfer by making structural changes such as addition of the extra equipment and using different heat transfer fluids. Researchers have generally focused on lots of ways such as twisted tapes (Gürsoy et al. , 2022a, 2022b), baffles (El-Said et al.…”

“…This determined purpose reveals the novelty of this study. Based on this situation, the flow geometry in which the best PEC has been obtained in the study ( ER = 2.5 and P/d = 3.0) conducted by Gürsoy et al. (2022a, 2022b) has been used for this investigation.…”