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Double pipe heat exchangers, or DPHEs, are employed in the power, oil, and process sectors. They cannot handle demanding applications. They have restrictions if they have to be utilized for heavy-duty applications. To get beyond these restrictions and use them for heavy-duty applications, heat transmission must be improved. In this work, a DPHE fitted with bowl-cut twisted tapes at different scale ratios (25, 50, and 75%) width (D) of bowl-cut from the center and circulated with TiO2/CuO hybrid nanofluids (NFs) is studied to assess its friction factor, thermal performance factor and Nusselt number. The working fluid was TiO2/CuO hybrid nanofluids (NFs) at varying concentrations (0.01, 0.03, and 0.05%) with Reynolds numbers from 2000 to 12,000. The bowl-cut twisted tape's twisted ratio (H/D = 3) was kept constant. The hybrid NFs' Nusselt number improvement was 66.09% more than that of the conventional tube. For varying scale ratios, the improvement in heat transfer was found to be 83.35, 115.31, and 172% with the bowl-cut twisted tapes and hybrid NFs. It was discovered that the friction factor penalty was 8.28, 0.83, and 1.075 times greater than that of the carrier fluid. Additionally, it was noticed that the thermal performance factor (TPF) was 1.65 times higher than the original fluid. [ABSTRACT FROM AUTHOR]

Pin-fin cooling is a significant method for managing high temperatures in gas turbine blades during operation. This study recommends the employment of a pencil-shaped and a circular pin fin to improve the channel’s heat transfer efficiency, based on both experimental and computational examinations. Numerical simulations with Reynolds numbers ranging from 10,000 to 80,000 are used to explore and compare the flow and heat transfer properties of a wedge channel with three rows of staggered pencil and circular-shaped pin fins with a diameter of 12 mm. The investigation revealed that staggered arrangement of pencil pin fins affects flow pattern and heat transfer properties differently. Compared to the pencil pin fins, heat transfer is enhanced by 11.72%, and the pressure drop from pencil pin fins is minimized by 72.2%. Furthermore, compared to the smooth channel, the Nusselt number for circular fins shows an increase of 40%. When comparing pencil fins to the smooth channel, the Nusselt number increases by 18%. As a result compared to circular fins, the thermal performance factor increases by 35.2%. [ABSTRACT FROM AUTHOR]

An inefficient heating system with poor air circulation can significantly hinder transfer of in an air heater. This study aims to evaluate the thermal exchange and frictional performance of air flowing inside a tube by experimenting it with various insert arrangements. According to the literature, twisted tape and helix-shaped tape inserts induce greater turbulence in the airflow, leading to higher heat transfer rates but with a copious pressure drop. Conversely, some inserts produce lower heat transfer rates but with a meager frictional pressure drop. In this study, selection of inserts was made by combining those with high heat transfer efficiency and those with low friction factors. The chosen insert configurations include Continuous Twisted tapes with square Holes (CTH), Discontinuous Twisted tapes with square Holes (DTH), Y-type inserts with holes (Y-TYPE), and Discontinuous Twisted tapes with V-shaped Winglets (DTHW). The study enumerates the functioning of an air heater with various inserts by analyzing the Nusselt number, friction factor, Thermal Enhancement Factor (TEF), and entropy generation. Experimentations were conducted at five various flow rates of air, with Reynolds numbers in the range between 30,000 and 95,000. The findings vindicate that Y-TYPE inserts achieved higher heat transfer with a lower drop in pressure when compared with other inserts. [ABSTRACT FROM AUTHOR]

The thermal lattice Boltzmann method (TLBM) is used to analyze the overall performance for upstream and downstream wedge ribs microchannels (MC) under slip flow conditions. The thermal–hydraulic enhancement criterion is investigated to evaluate the performance of the channel and compare it for various roughness MC. In order to improve the channel performance, two alternative artificial roughness geometry, upstream and downstream wedge ribs, are taken both on the top and bottom walls of the microchannel with aspect ratio (AR) 7, where AR = L/H; L and H are channel length and height respectively in micrometer (μm). This study focused on simulating temperature profiles, velocity vectors in terms of stream lines, pressure gradients, and friction factor in terms of Poiseuille number as well as heat transfer rate in terms of Nusselt number (Nu). The overall performance of the channel is calculated based on flow friction and heat transfer rate for different Knudsen numbers (Kn) ranging from 0.01 to 0.10 with upstream and downstream wedge ribs height up to 20% of channel height. The results have been compared with previously published work and are found a very good agreement. The analysis revels that, the vortices are formed behind each upstream wedge rib, whereas they are created in front of each downstream wedge rib. The size and shape of vortices are influenced by Kn. As Kn increases from 0.0 to 0.10, the fluid circulation area becomes smaller for upstream wedge ribs MC, while it is changing very slowly for downstream wedge ribs MC; hence, the pressure gradient is also responsible for changing Kn. The flow friction is linearly decreased with increasing Kn but significantly increased with ribs height. But compared to the smooth channel, the friction is significantly increased for upstream and downstream wedge ribs MC. The average rate of heat transfer in terms of Nu is also linearly decreased with increasing Kn, but Nu increased with ε for lower Kn and decreased for higher Kn. Therefore, compared to smooth MC, Nu increased and decreased for the same for upstream and downstream wedge ribs MC. Finally, the performance enhancement (η) is calculated, and it is found that η decreased with increasing Kn for upstream and downstream wedge ribs MC. The higher performances are indicated for lower Kn as well as lower ribs height. For all cases, the better performance is noted for downstream wedge ribs MC compared to upstream MC. [ABSTRACT FROM AUTHOR]

This research paper details an experimental study on airflow dynamics in a solar air heater. The heater's design incorporates unique, discrete V‐shaped ribs with staggered elements to enhance thermal performance. The study investigates the influence of various roughness parameters on flow characteristics. These parameters include a relative coarseness pitch (P/e) ratio of 12, a rib inclination angle (α) of 60°, a relative coarseness height (e/Dh) of 0.043, and a staggered element arrangement with a positioning ratio (p′/P) of 0.65. Additionally, the investigation includes scenarios with three gaps (Ng) between elements and a gap‐to‐rib width (g/e) ratio of 4. The research focuses on how changes to the Reynolds number, ranging from 3000 to 14,000, and alterations to the ratio of staggered element positioning to rib height (r/e), from 2 to 5, impact the flow dynamics. The outcomes indicate a significant boost in heat transfer performance, with the Nusselt number rising to 3.76 compared with a conventional smooth duct. The highest thermal efficiency recorded was 86%, at an r/e ratio of 3.5. These results underscore the potential of using discrete V‐ribs with staggered elements in rectangular ducts to improve heat transfer efficiency. [ABSTRACT FROM AUTHOR]

This research study investigated the impact of various configurations of semi-circular or half-round ribs on the thermal performance and frictional factor characteristics of a rectangular duct. During this research study, the ribs were provided on the inner surface of the test section's bottom wall. Six distinct configurations of semi-circular ribs varying from continuous to hybrid arrangement were used. The range of Reynolds number was varied from 13,500 to 34,800; while the ratio of rib pitch to rib height (P/e ratio) was kept constant at 8. The ratio of the height of rib to hydraulic diameter of duct (also known as blockage ratio) was kept at 0.114. The results of experimental investigation showed that the Nusselt number ratio obtained was ranging from 1.36 to 2.74, while the friction factor ratio ranges from 1.70 to 4.51. The overall enhancement ratio for all configurations obtained was in the range of 1.06–1.80 times to that of plain duct. Among all rib configurations, the hybrid rib configuration showed superior ratio of Nusselt number and intermediate increase in ratio of friction factor as compared to all the other rib configurations. Hybrid rib configuration showed overall enhancement ratio values ranging from 1.45 to 1.80 times as compared to that of plain duct (duct without ribs) within the specified range of Reynolds number. The results of study showed that the hybrid configuration of semi-circular ribs exhibited superior overall thermal enhancement as compared to that of remaining tested rib configurations. [ABSTRACT FROM AUTHOR]

Triply periodic minimal surfaces (TPMS) represent an innovative approach to the design of heat exchangers, enabling the optimisation of thermal and hydraulic performance. This study presents a comparative analysis of three geometric TPMS configurations: sheet gyroid, skeletal gyroid, and the newly proposed combined gyroid geometry. Using numerical analysis based on simulations of fluid flow and heat transfer, key parameters such as the heat transfer coefficient, Nusselt number, friction factor, Chilton–Colburn j-factor, and pressure drop were evaluated. The results demonstrated that the combined gyroid geometry achieves the highest heat transfer efficiency, exhibiting significant improvements in the Nusselt number and heat transfer coefficient across the entire flow range. Simultaneously, it maintains low pressure losses, making it well suited for applications demanding high thermal performance with minimal energy losses. This study highlights the potential of TPMS geometries for optimising heat exchanger design and opens new paths for their implementation in industrial systems. [ABSTRACT FROM AUTHOR]

Abstract The thermal lattice Boltzmann method (TLBM) is used to analyze the overall performance for upstream and downstream wedge ribs microchannels (MC) under slip flow conditions. The thermal–hydraulic enhancement criterion is investigated to evaluate the performance of the channel and compare it for various roughness MC. In order to improve the channel performance, two alternative artificial roughness geometry, upstream and downstream wedge ribs, are taken both on the top and bottom walls of the microchannel with aspect ratio (AR) 7, where AR = L/H; L and H are channel length and height respectively in micrometer (μm). This study focused on simulating temperature profiles, velocity vectors in terms of stream lines, pressure gradients, and friction factor in terms of Poiseuille number as well as heat transfer rate in terms of Nusselt number (Nu). The overall performance of the channel is calculated based on flow friction and heat transfer rate for different Knudsen numbers (Kn) ranging from 0.01 to 0.10 with upstream and downstream wedge ribs height up to 20% of channel height. The results have been compared with previously published work and are found a very good agreement. The analysis revels that, the vortices are formed behind each upstream wedge rib, whereas they are created in front of each downstream wedge rib. The size and shape of vortices are influenced by Kn. As Kn increases from 0.0 to 0.10, the fluid circulation area becomes smaller for upstream wedge ribs MC, while it is changing very slowly for downstream wedge ribs MC; hence, the pressure gradient is also responsible for changing Kn. The flow friction is linearly decreased with increasing Kn but significantly increased with ribs height. But compared to the smooth channel, the friction is significantly increased for upstream and downstream wedge ribs MC. The average rate of heat transfer in terms of Nu is also linearly decreased with increasing Kn, but Nu increased with ε for lower Kn and decreased for higher Kn. Therefore, compared to smooth MC, Nu increased and decreased for the same for upstream and downstream wedge ribs MC. Finally, the performance enhancement (η) is calculated, and it is found that η decreased with increasing Kn for upstream and downstream wedge ribs MC. The higher performances are indicated for lower Kn as well as lower ribs height. For all cases, the better performance is noted for downstream wedge ribs MC compared to upstream MC.

This study focuses on improving heat transfer by converting one of the corners of the duct to a rounded structure. To study the effect of dimpled shaped protrusions and intrusions on the rounded corner triangular duct with a constant radius of curvature by varying relative streamwise distance (z/e) with a constant transverse distance x'/e = 10,14 and 18. Steady-state, turbulent flow heat transfer under thermal boundary conditions is to be analyzed by varying different Reynolds numbers (5600 to 21000). The duct with dimple-shaped protrusions and intrusions is compared with a simple triangular duct. Optimization of relative horizontal distance (z'/e) by keeping constant protrusion to protrusion distance as z/e = 28 and relative transverse distance as x/e = 10, 14, and 18. It was noted that there was a significant loss in friction and a rise in heat transfer. The relationship between friction factor and Nusselt number was formulated using operating and roughness parameters, using the data collected from the numerical investigation. The friction factor increases significantly with roughness elements, and it is maximum for x'/e = 20 at a low Reynolds number. Nusselt number increases with roughness elements, and it is maximum for x'/e = 14 for all Reynolds numbers and all the models. Enhancement of Nusselt number is due to increase of local heat transfer because of local vortex neat heat transfer zone. The maximum outlet temperature is obtained at a low Reynolds number. The maximum temperature of the heated surface is obtained for Rc = 0.67 h and the minimum for Rc = 0.33 h. [ABSTRACT FROM AUTHOR]

The study aims to examine how duct length affects the performance of a solar air heater (SAH) with a D‐shaped ribbed absorber plate, compared to a smooth absorber plate. The optimized D‐shaped ribs from previous research investigations are utilized in the present work to explore the absorber plate's length influence on the Nusselt number. The study reveals a slight decrease in the Nusselt number as the length of the absorber plate with D‐shaped ribs is increased. The observed behavior is attributed to the diminishing capacity of air to extract heat from the heated surface within the elongated duct. Moreover, the study calculates the pressure drop and thermo–hydraulic performance parameter (THPP) associated with the D‐shaped ribs and formulates correlations to establish a quantitative understanding of the relationship between duct length and D‐shaped rib performance. The maximum value of THPP was found to be 1.17 within the considered range of duct height. Furthermore, correlations have been derived for the Nusselt number and friction factor in terms of duct length to hydraulic diameter ratio and Reynolds number with maximum deviations of +1.7 and +2.13, respectively. These correlations serve as valuable tool for engineers and researchers seeking to optimize the design of SAHs, enabling them to balance the benefits of D‐shaped ribs with the considerations of duct length. This research contributes to the growing body of knowledge of SAH design, offering insights into the trade‐offs and intricacies of utilizing D‐shaped ribs and adjusting duct length for improved THPP. [ABSTRACT FROM AUTHOR]

This investigation is conducted to analyze the artificial surface roughness influence on the heat flow and friction characteristics within the ducts of solar air heaters (SAHs). This research aims to investigate the consequences of applying spherical-shaped surface roughness to the absorber in a linear and staggered manner with the intention of enhancing the heat transfer efficiency. The utilization of roughness elements in the shape of spheres is aimed at augmenting the heat transfer characteristics; however, it is crucial to acknowledge that this enhancement is concomitant with an elevation in pumping power due to heightened friction. An experimental campaign encom- passes a diverse set of operational and device parameters. These parameters include the Reynolds number (Re), which varies from 3,000 to 8,000. Additionally, the roughness pitch-to-height ratio (p/h) ranges from 10 to 20, while the roughness gap-to-height ratio (w/h) ranges from 4 to 8. Throughout the trials, a constant value of 0.06 is maintained for the roughness height-to-hydraulic diameter ratio (h/D) and an amount of 5 is maintained for the duct width-to-height ratio (W/H). The outcomes of this study indicate a considerable increase in the Nusselt number, ranging from 50.47% to 69.51%, concurrently with a substantial rise in the friction factor, ranging from 27.76% to 144.75%, when compared to designs using a smooth absorber surface in the context of SAHs. By utilizing the experimental data, relationships between the friction factor and the Nusselt number are established based on the artificial roughness parameters and the operating conditions. The current study’s findings significantly advance our knowledge of and ability to improve SAH systems’ heat transfer and friction characteristics. Thus, this investigation improves our understanding of these systems operational behavior in many situations. [ABSTRACT FROM AUTHOR]

Plate heat exchangers have served various industrial applications for decades, with brazed plate heat exchangers (BPHE) emerging as preferred choices due to their favorable operating conditions. While extensive research has been conducted on flow patterns in gasketed plate heat exchangers, similar studies for BPHE have been lacking, given their analogous geometry. However, recent years have witnessed a surge in research focusing on single and multi-phase flow dynamics. Advancements in computational fluid dynamics (CFD) have furthered our understanding by providing insights into flow and heat transfer patterns, while also reducing the need for costly experimental tests of different geometries. This has facilitated the adoption of parametrization, bolstered by the feasibility and accuracy of numerical models. Nevertheless, substantial research remains to be undertaken to develop comprehensive models capable of integrating multiple geometric and flow parameters. This article examines existing research on BPHE and outlines potential areas for future exploration to address current research gaps. [ABSTRACT FROM AUTHOR]

During solar cell operation, most light energy converts to heat, raising the battery temperature and reducing photoelectric conversion efficiency. Thus, lowering the temperature of solar cells is essential. Nanofluids, with their superior heat transfer capabilities, present a potential solution to this issue. This study investigates the mechanism of enhanced heat transfer by nanofluids in two-dimensional rectangular microchannels using the two-phase lattice Boltzmann method. The results indicate a 3.53% to 22.40% increase in nanofluid heat transfer, with 0.67% to 6.24% attributed to nanoparticle–fluid interactions. As volume fraction (φ) increases and particle radius (R) decreases, the heat transfer capability of the nanofluid improves, while the frictional resistance is almost unaffected. Therefore, the performance evaluation criterion (PEC) of the nanofluid increases, reaching a maximum value of 1.225 at φ = 3% and R = 10 nm. This paper quantitatively analyzes the interaction forces and thermal physical parameters of nanofluids, providing insights into their heat transfer mechanisms. Additionally, the economic feasibility of nanofluids is examined, facilitating their practical application, particularly in solar cell cooling. [ABSTRACT FROM AUTHOR]

Pin fin arrays, which have a high heat transfer capacity and minimal pressure loss, are currently being used as the primary cooling technique for the turbine trailing edge cooling channel used in modern gas turbines. To enhance the heat transmission efficiency of the channel, this study proposes the use of a circular-shaped pin and a teardrop pin, through both experimental and numerical investigations. The numerical simulations conducted in the Reynolds number range of 10,000 to 80,000 are used to investigate and compare the flow and heat transfer parameters of a wedge channel which has three rows of staggered circular-shaped and teardrop-shaped pin fins with a diameter of 12 mm. The experiment showed that teardrop pin fns with staggered arrangement has different effect on flow pattern and heat transfer characteristics. Heat transfer is increased by 10.45% when compared to the circular pin fins and the pressure drop of teardrop pin fins is reduced by 54.6%.Therefore thermal performance factor exhibits a 25.4% increase when compared to circular fins. [ABSTRACT FROM AUTHOR]

The present investigation employed computational techniques to analyze the heat transfer and fluid-flow properties of a Cu-water nanofluid moving through a rectangular micro-channel. The upper wall of the micro-channel is thermally insulated, while the lower wall is equipped with a ribbed surface maintained at a greater temperature than the fluid entering the channel. The governing equations were discretized using the finite volume method and solved using the ANSYS-FLUENT 16.0 CFD software. The study investigated the influence of many parameters, such as the Reynolds number (20 ≤ Re ≤ 200), volume percentages of nanoparticles (1% ≤ φ ≤ 8%), and rib height. The numerical results demonstrate that when the height of the ribs rises, e = 20 μm, e = 30 μm, and e = 40 μm, the contact surface area between the ribs and the nanofluid similarly increases. As a result, the friction factor of the heated surface rises, regardless of whether the Reynolds numbers are low or high. Furthermore, numerical analysis suggest that the average friction factor diminishes as the Reynolds number rises for all rib heights. Ribs in the micro-channel facilitate improved mixing, resulting in heightened heat transfer. The impact is intensified by augmenting the concentration of nanoparticles and the Reynolds numbers at all rib heights. [ABSTRACT FROM AUTHOR]

Solar air heater (SAH) is one of many applications of solar energy, but it has low thermal performance. To cater to this issue, a novel corrugated jet-impinging channel has been proposed for the absorbing plate of SAHs. The Nusselt number, pressure loss pumping power, and friction factor were computed by experimental and numerical studies for three different arrangements of jets, i.e., 1 × 1 square, 2 × 2, and 3 × 3 jet array with three target plates, i.e., smooth, trapezoidal, and sinusoidal corrugated plates over the Reynolds number range of 1740-2700 and jet-to-target plate spacing of 5.1-14.6. It was observed that jet-to-target plate distance and multiple jets impinging can affect the heat transfer enhancement significantly. An optimization study has been performed using the statistical Taguchi method. The optimum value of Nusselt number was found for the trapezoidal corrugated target plate, with 3 × 3 multiple jet impingement, jet-to-target plate distance of 5.1, and Reynolds number value of 2700, while the optimum value of friction factor was found for 3 × 3 jet impingement. Computational fluid dynamics (CFD) and experimental data are found to be in good agreement. An increase of 11 times was observed in the thermal performance factor as compared to the base case. Trapezoidal corrugation seems to be the effective profile for SAHs. [ABSTRACT FROM AUTHOR]

An experimental investigation is carried out to analyze the thermo-hydraulic characteristics of a triangular solar air heater duct having transverse ribs with gaps. The roughness parameters, such as non-dimensional pitch (̅P/e or) and non-dimensional height (̅e/Dh or) are kept in the range of 4.88-20 and 0.021-0.044, respectively. Reynolds number (Re) is kept in the range of 4000-18,000. Two and three gaps of each of 0.01 m are provided to each odd and even number ribs, respectively. Non-dimensional primary width (w1/W) and non-dimensional secondary width (w2/W) are kept constant at 0.29 and 0.4, respectively. A maximum heat transmission of 3.14 times that of the base model is achieved for the transverse ribs with gaps having non-dimensional pitch and height of 9.76 and 0.044, respectively, at Re = 18,000. In the parametric range, the highest friction factor of 3.88 times the base model is encountered for the non-dimensional pitch and height of 4.88 and 0.044, respectively, at Re = 4000. The highest thermal enhancement ratio of 2.31 is reported for the non-dimensional pitch and height of 9.76 and 0.044, respectively, at Re = 18,000. The correlation for the Nusselt number and friction factor is formulated, agreeing with experimental data within ±12% and ±8% deviation, respectively. [ABSTRACT FROM AUTHOR]

Breaking laminar sub-layer and creating turbulence flow is the main characteristic of solar air heater to increase heat transfer. Several geometries have been employed, and their effect on heat transfer has been studied by researchers. These effects are studied in form of Nusselt number (Nu) and friction factor (Fr) rise and correlations for them are developed. In current experimental study, a novel geometry in shape of rhombus is used as roughness. Rhombus shape is selected because of its feature of v shape and converging nature on its end sides which helps to guide the flow of air and offer more secondary flow and less resistance. The geometrical and flow parameters are varied as number of elements (W/Vr), relative diagonal length (dr/e), Reynolds number (Re), relative roughness height (e/Dh), relative roughness pitch (P/e) within range of 8–12, 6–13.33, 2500–14200, 0.0202–0.0337 and 6–14, respectively. Variation of 258–378% and 215–148% more compared to smooth plate is achieved for Nu and Fr, respectively. Nu increases when values of P/e increases and attains maxima at P/e = 10, e/Dh = 0.03375, W/Vr = 10 and dr/e = 9.6. Experimental correlations are grounded in actual data making them applicable to real-world scenarios and practical applications. The deviation between Nu and Fr calculated from the correlation and experimentation was ± 12% and ± 10%, respectively. [ABSTRACT FROM AUTHOR]

This article presents a study of aerothermal performance of tubes with regularly-spaced multi-channel twisted tape elements (RS-MTT) installed. This research aimed to find the proper design RS-MTTs that induce swirl flow which potentially improves fluid mixing between the core fluid and the fluid near the tube wall, thereby accelerating the heat transfer rate. Additionally, the effects of Reynolds numbers and free-spacing ratios (s/y) on heat transfer, friction loss, and thermal performance behaviors were examined. The RS-MTTs having different free-spacing ratios (s/y) of 0.0, 0.25, 0.5, 0.75, and 1.0 were tested. Air was utilized as the testing fluid in experiments with Reynolds numbers (Re) spanning from 6000 to 20,000. The utilization of RS-MTTs with s/y = 0.0, 0.25, 0.5, 0.75, and 1.0 augmented heat transfer rates up to 1.74, 1.80, 1.85, 1.90, and 2.15 times given by the plain tube alone while the friction factors increased by 4.22, 4.61, 3.87, and 4.05 times, respectively. At the lowest Reynolds number of 6000, the thermal enhancement factors of the tube containing the RS-MTTs with s/y = 0.0, 0.25, 0.5, 0.75, and 1.0 reached the maximum values of 1.42, 1.35, 1.31, 1.27, and 1.23, respectively. Among the RS-MTTs tested, the RS-MTT with s/y = 0.0 showed the best thermal enhancement factor of 4.56%, corresponding to the heat transfer augmented of 11.52% with a friction penalty of 8.71%. [ABSTRACT FROM AUTHOR]

The present work experimentally investigates the effect of novel turbulators on improving heat exchanger (HE) performance. Tests are conducted by insertion of three types of turbulators, 3PS, 4PS, and 5PS, including two pitch ratio PR (5-3.76). The results showed that the enhancement in heat transfer (HT) when using 5PS was more than the remaining two types. The greatest worth was at the lowest pitch ratio. The outcomes of experiments showed that the enhancement in the Nusselt number for each type of 5PS, 4PS and 3PS for small pitch ratio was 194%, 177% and 164% more than that of the plain tube, correspondingly. Also, the thermal performance factor, friction factor, and Nusselt number are all increased as the pitch ratio decreases. As a result, the small pitch ratio delivers a more considerable rate of HT and lower loss in friction. In addition, the results showed that the factor of thermal performance was more significant compared to unity for each type studied, and the maximum value of thermal performance factor acquired at η=1.54 is accomplished for the 5PS turbulators. The Correlations between the friction factor and Nusselt number were evolved for the range of Reynolds number (Re) of 12385 to 24766. The most relevant results of the evaluated study were presented to aid researchers in understanding the advances in HT enhancement in double pipe HE using novel turbulators inserts. [ABSTRACT FROM AUTHOR]

Determination of the geometrical parameters of the heat exchanger has important effects on the thermohydraulic performance of the heat exchanger. In this study, the effects of geometric parameters of a plate heat exchanger on thermohydraulic performance have been extensively investigated using computational fluid dynamics (CFD). Parametric studies were performed on 8 different corrugated channel geometries with various chevron angles (β) and aspect ratios (2b/λ) for Reynolds numbers ranging from 500 to 3000. An entire fluid channel was numerically studied using the same mass flow rate and the Reynolds number. As results of the study, temperature distribution, pressure gradient, velocity, turbulent kinetic energy distribution, Nusselt number, friction factor, and flow properties were evaluated comparatively for each case. It was determined that the sinusoidal corrugations promote the turbulence intensity and the swirling flow which leads to thermal boundary layer mitigation and enhanced convection heat transfer in response to the increasing of aspect ratio. The results of the study show that the (CFD) model is a reasonable and effective technique for displaying 3D contour plots, streamlines, and determining performance parameters. [ABSTRACT FROM AUTHOR]

In recent scenario world is facing the problem of energy consumption. Researchers are keen on developing less energy consuming devices; in this regard, heat transfer using nanofluid has got the attention of current researchers for application in heat exchangers. In present study, an experiment was performed on double pipe heat exchanger using CuO-water nanofluids and sodium lauryl sulphate as the surfactant to examine the thermal performance factor (TPF) and pressure drop. The studies were conducted for a single phase fully developed flow with volume fractions of 0.005%, 0.02%, 0.04%, and 0.07% in the turbulent range between Reynolds numbers 5500 and 15,000. Along with thermal conductivity, Brownian motion and thickness of interfacial layer are also responsible for heat transfer enhancement in heat exchangers. For a volume fraction of 0.07% at Reynolds number 5500, the maximum enhancement in Nusselt number was observed 67.9% with the penalty of 189.47% increase in friction factor. The highest TPF recorded during the experiment is 1.18 for a volume fraction of 0.07% at 5500 Reynolds number. In present study a novel correlation was also developed for Nusselt number and friction factor. For better understanding the characterization of CuO nanoparticle, XRD, FeSEM, and EDS testing were conducted in the laboratory. [ABSTRACT FROM AUTHOR]

Turbine inlet air temperatures are extremely high, which can result in blade material damage. As a result, cooling the turbine blades is required, and a variety of cooling techniques have been introduced. The majority of the previous research on pin fins has focused on circular fins using a wedge duct to apply a constant temperature and uniform heat flux to the end wall and pin fin surfaces. The present study compares seven oblong pin-fins to seven circular pin fins in a wedge duct with a Reynolds number range of 10,000–50,000 and a constant heat flux (surface) of 3280 W/m2 applied to the endwall and surfaces of the oblong pin fin. The results indicate that the friction factor for oblong fins is 14% lower than for circular pin fins. The thermal performance factor is increased by 11.4%. The thermal performance factor can be improved by using oblong pin fins with higher Reynolds numbers. [ABSTRACT FROM AUTHOR]

The need to reduce energy usage is one of the main issues with creating heat exchangers. This may be accomplished by increasing the heat transfer augmentation which results in the higher thermal performance factor (TPF). The aim of the present study is to experimentally determine the thermal hydraulic performance factor of DPHE with a novel wire coil insert. The experiments were performed in the range of Reynolds number (Re): 5500–15000, and the data were recorded for fifteen different combinations of wire coil (WC) inserts, including five different pitch ratios (P/Dc = 0.625, 1.25, 1.875, 2.5 and 3.125) and three wire diameters (d = 1, 1.5 and 2 mm). The application of WC inserts results in notable enhancement in heat transfer rate as compared to different TT. For the given range of Re, the heat transfer performance was improved to a maximum of 126.7% for pitch ratio (PR) P/Dc = 0.625 at wire diameter (d = 2 mm), while friction was recorded in the range of 2.67–4.71 times higher compared to PT. The TPF (η) with WC inserts for all combination was recorded greater than unity. The maximum value of TPF (η) obtained for wire coil inserts is 1.35 with PR (P/Dc = 0.625) and (d = 2 mm). Since TPF(η) in all cases is greater than 1.0 which shows that it is an effective approach. [ABSTRACT FROM AUTHOR]

This study investigated the convective heat transfer coefficient and friction coefficient in a copper helical double pipe heat exchanger utilizing biosynthetic aqua-based silver (Ag) nanofluids prepared with Histiopteris incisa leaf extract. The nanofluids were characterized using UV–Vis spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and high-resolution transmission electron microscopy. The experimental approach involved the constant heat flux method under laminar flow conditions with flow rates ranging from 100 to 160 litres per hour (LPH). Biosynthesized aqua-based silver nanofluids were synthesized using a one-step biosynthesis method, resulting in volume concentrations ranging from 0.3 to 0.9%. Our findings demonstrated that the biosynthesized aqua-based silver nanofluids exhibited enhanced convective heat transfer compared to pure water. Additionally, the heat transfer coefficient showed an increasing trend with higher volume concentrations of biosynthesized aqua-based silver nanofluids. Notably, the most significant improvement in convective heat transfer, reaching 40%, was achieved with a 0.9% volume concentration of biosynthesized aqua-based silver nanofluids, a flow rate of 140 LPH, and a Dean number of 1400. Moreover, the friction coefficients observed for biosynthesized aqua-based silver nanofluids were 35% higher than those of water in the Dean number range of 1400–2400. [ABSTRACT FROM AUTHOR]

This article presents an in-depth analysis of internally finned tube heat exchangers, which are used in a broad variety of condensers and evaporators for air conditioners, as well as radiators for vehicles and solar air heaters, amongst other places. The growing need for cooling systems that are more efficient and heat exchangers that take up less space has inspired many studies in this area of expertise. This research uses both experimental and computational analysis to compare and contrast the efficacy of various heat transfer enhancement processes in internally finned tube heat exchangers concerning the impacts they each have and the operating parameters they each need. This study aims to investigate how altering the fins' design affects heat transfer and pressure drop under varying operational situations. This paper examines the ranges in which these correlations have been verified, as several correlations have been created to assist in estimating heat transfer and pressure drop characteristics on internally finned tube heat exchangers. This study extensively delves into various analytical approaches such as Log Mean Temperature Difference (LMTD), Computational Fluid Dynamics (CFD), Finite Element Analysis (FEA), and other methodologies specifically tailored to address the unique goals of the particular problem. To derive a conclusion with practical significance, we categorize these relationships into multiple groups and conduct a comparative analysis. [ABSTRACT FROM AUTHOR]

The thermal-hydraulic performance of plain tubes with and without wire coils in turbulent regimes is investigated experimentally and numerically. The effects of wire coil distribution (circular cross section) within the tube were explored experimentally, and water was employed as the working fluid. The numerical simulation was carried out using software programmer ANSYS Fluent 2019 R3 using the finite-volume approach. In the turbulent regime, six cross-sectioned wire coils were analyzed, including: circular, rectangular, hexagonal, square, star shape, and triangle. The utilization of a tube with a wire coil has been shown to increase heat transfer rate and pump consumption. The results indicate a high level of concurrence, as the deviations are all below 8%. Compared with plain tube, the wire coils, according to the arrangement (TWD), gave the best PEC. The heat transfer enhancement ability of different cross sections follows the following order: StCS > RCS > HCS > SqCS > CCS > TCS. Also, the sequence of pump consumption for each cross section is as follows: RCS > StCS > SqCS > HCS > CCS > TCS. [ABSTRACT FROM AUTHOR]

The present research investigates heat transfer and the flow characteristics of periodically corrugated wavy channels numerically under pulsatile flow conditions. The numerical method used here is Lattice Boltzmann Method (LBM), and the validation of the study is done by Ansys-Fluent which is finite volume based commercial Computational Fluid Dynamics (CFD) code. For modeling walls, bounce-back method, namely, staircase method and three different curved boundary treatments, which are extrapolation, Filippova-Hänel (FH) and Mei-Luo-Shy (MLS), are used. For modeling constant temperature at walls, staircase method and the same curved wall treatments are used. Corrugated channels have a sharp wavy peak, and its inclination angle is 30°. Two different minimum channel heights are considered, which are 5 and 10 mm in corrugated channels. Flow regime is assumed as laminar (50 < Re < 300) and Prandtl number is kept as 0.7. Four kinds of different sinusoidal pulsatile flows are used with a combination of two different dimensionless frequencies and dimensionless amplitudes. For varying Reynolds number range, Nusselt number and friction factor are calculated. Narrow channel creates higher Nusselt number and friction factor than wide channel. At low Reynolds number, Nusselt number does not changed with pulsatile flow conditions, however at high Reynolds number cases of lower dimensionless frequency and higher dimensionless amplitude produce higher Nusselt numbers. Lower dimensionless frequency cases produce higher Nusselt number than higher dimensionless frequency cases. Pulsatile flow conditions have no effect on friction factor and for narrow and wide channel. Nusselt number prediction of FVM is close to STR and EXT for all cases of narrow channels, and close to the FH, MLS and EXT for all cases wide channel. Correlation equations for Nusselt number and friction factor are constructed by deep neural network (DNN) algorithm. [ABSTRACT FROM AUTHOR]

Copyright of SDU Journal of Engineering Sciences & Design / Mühendislik Bilimleri ve Tasarım Dergisi is the property of Journal of Engineering Sciences & Design and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, we aim to investigate the heat transfer and flow characteristics of diverse hybrid nanofluids (CuO-ZnO-Water, EG-Water, CuO-EG-Water, SiO2-EG-Water, and Al2O3-EG-Water) as coolants across eight discrete inlet velocities in a shell and tube heat exchanger. Various materials (copper, stainless steel, titanium, and carbon steel) have been employed for the tubing to optimize system performance. The impact of Reynolds number concerning hybrid nanofluids on Nusselt number and friction factor was assessed in this research. The results of the numerical simulations are found to agree well with experimental results within an average deviation of 1.8%. The results indicated the superior heat transfer capabilities of the hybrid nanofluid compared to the base fluid across all conditions. The outcomes revealed the superior heat transfer capabilities of the CuO-ZnO-Water hybrid nanofluid under all tested conditions. When employing CuO-ZnO-Water as a coolant, a substantial increase of over 9% in temperature reduction was observed, as opposed to the approximately 6% attained by other hybrid nanofluids at a lower velocity of 0.5 m/s. Notably, higher Reynolds numbers corresponded to increased Nusselt numbers and decreased friction factors. The decline percentage of the friction factor was 43% at Reynolds number ranging between 10,000 to 40,000. We emphasize the imperative need to optimize nanoparticle types for crafting hybrid nanofluids to enhance the performance of industrial heat exchangers and their coolant efficiency. Ultimately, the utilization of hybrid nanofluids in conjunction with shell and tube heat exchanger systems has yielded a notable enhancement in the overall thermal efficiency of these systems.

Lattice structures such as triply periodic minimal surface (TPMS) structures have gained significance due to advancements in additive manufacturing, particularly 3D printing, which enable their engineering to be tailored to specific applications, such as heat exchangers. While traditional heat exchanger designs have been extensively studied, investigations into the thermal performance of TPMS structures are limited. Considering the extensive range of the geometric design variations in TPMS structures, highly efficient structures on par with the performance of conventional heat exchanger designs can be expected. This study aims to comprehensively evaluate the thermal and flow characteristics of a specific TPMS structure (Fischer Koch S), and, in particular, the impact of various volume fractions on its heat transfer performance and on its friction factor. Another key objective of this study is to develop Nusselt and friction factor correlations as a function of the investigated volume fractions for potential use in future design tools. To this end, a broad CFD study was carried out. Additionally, this study provides insights into the procedures involved in generating Fischer Koch S geometries and the modeling methodology employed in CFD investigations. Based on the results of the CFD study, the thermal and fluid dynamic performances of Fischer Koch unit cells were evaluated, resulting in heat transfer coefficients up to 160 W/m2K for the investigated structures. A comparison between the heat transfer coefficient of the examined TPMS structure and a conventional plate heat exchanger suggested a potential increase in the heat transfer coefficient of approximately 35%. The generated CFD data were subsequently utilized to formulate fitting correlations for the Nusselt number and friction factors as a function of the volume fraction. The fitted parameters of these correlations are provided in this work. [ABSTRACT FROM AUTHOR]

In this study, we aim to investigate the heat transfer and flow characteristics of diverse hybrid nanofluids (CuO-ZnO-Water, EG-Water, CuO-EG-Water, SiO2-EG-Water, and Al2O3-EG-Water) as coolants across eight discrete inlet velocities in a shell and tube heat exchanger. Various materials (copper, stainless steel, titanium, and carbon steel) have been employed for the tubing to optimize system performance. The impact of Reynolds number concerning hybrid nanofluids on Nusselt number and friction factor was assessed in this research. The results of the numerical simulations are found to agree well with experimental results within an average deviation of 1.8%. The results indicated the superior heat transfer capabilities of the hybrid nanofluid compared to the base fluid across all conditions. The outcomes revealed the superior heat transfer capabilities of the CuO-ZnO-Water hybrid nanofluid under all tested conditions. When employing CuO-ZnO-Water as a coolant, a substantial increase of over 9% in temperature reduction was observed, as opposed to the approximately 6% attained by other hybrid nanofluids at a lower velocity of 0.5 m/s. Notably, higher Reynolds numbers corresponded to increased Nusselt numbers and decreased friction factors. The decline percentage of the friction factor was 43% at Reynolds number ranging between 10,000 to 40,000. We emphasize the imperative need to optimize nanoparticle types for crafting hybrid nanofluids to enhance the performance of industrial heat exchangers and their coolant efficiency. Ultimately, the utilization of hybrid nanofluids in conjunction with shell and tube heat exchanger systems has yielded a notable enhancement in the overall thermal efficiency of these systems. [ABSTRACT FROM AUTHOR]

An improved method for heat transfer calculation inside rough tubes is provided. The model has been obtained from a second assessment developed early by the authors on fluid flow in single-phase inside rough tubes. The proposed correlation has been verified by comparison with a total of 1 666 experimental available data of 34 different fluids, including air, gases, water and organic liquids. The proposal model covers a validity range for Prandtl number ranging from 0.65 to 4.52x104, values of Reynolds number from 2.4x10³ to 8.32x106, a range of relative roughness ranging from 5x10-2 to 2x10-6 and viscosity ratio from 0.0048 to 181.5. The proposed model provides a good correlation for 104=Re and Re<104, with an average error of 18.3% for 70.4% of the data and 16.6% for 74.8% of the data, respectively. The method presents a satisfactory agreement with the experimental data in each interval evaluated; therefore, the model can be considerate accurate enough for practical application. At the present time, in the available technical literature, a method with similar characteristics is unknown. [ABSTRACT FROM AUTHOR]

This work aims at determining the heat transfer enhancement as well as friction losses of CeO2 nanofluids (NFs) in a double pipe heat exchanger. Cerium Oxide nanopowder was characterised by Energy-Dispersive X-ray Spectroscopy (EDX), X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). Thermo-physical properties were measured at different temperatures and concentrations of the NF. Friction factor and Nusselt numbers were determined for various particles loading of 0.1%, 0.2% and 0.3%. Thermal conductivity enhanced by 7.92% to 12.9% than the based fluid. Experiments were performed for the range of Reynolds numbers of 2000 to 9000. Experimental results showed that for 0.3% concentration of NF, the maximum augmentation in the Nusselt number is 32.35% with a penalty of 1.18 times in terms of friction factor at a Reynolds number of 8720 in contrast to that of the carrier fluid. [ABSTRACT FROM AUTHOR]

The combination of passive and active heat transfer recovery techniques in channel flows has significant potential in terms of increasing thermal performance. Therefore, this study focused on the numerical examination of the flow and thermal behavior of pulsating flow in a straight duct containing a rhombus chamber. In the context of the study, iterations were solved using the finite volume method (FVM). The study was carried out for different pulsating amplitudes (A: 0.2, 0.4, 0.6, and 0.8), Strouhal numbers (St: 1, 2, 3, 4), and Reynolds numbers (200 ≤ Re ≤ 800). The surfaces other than the adiabatic lengths at the inlet and outlet of the duct were kept constant at Tw = 360 K. Results were compared with the results of the steady flow case. The effects of pulsating velocity and oscillatory parameters on Nusselt number, pressure drop, and performance factor were discussed. Velocity and temperature images were presented for different Reynolds numbers and pulsating components in the channel. The findings revealed that although the pulsating parameters significantly enhanced the heat transfer at increasing Reynolds numbers, they had a fairly low effect on heat transfer at the same Reynolds number. It was observed that at Re = 800, the Nusselt number formed a peak at St = 3 for all tested pulsating amplitudes. For the parameters of Re = 800, A = 0.6, and St = 2, heat transfer and performance factor in pulsating flow increased by 8.96 and 8.22 times, respectively, compared to steady flow conditions. [ABSTRACT FROM AUTHOR]

To enhance overall thermal performance factor of tubular heat exchanger, use of twisted tape has been very effective. Twisted tape creates turbulence in the flow which enhances rate of heat transfer and friction factor. Present experimental study aims to limit this penalty of increase in friction factor and achieve high thermal performance factor. For this, present article analyzes the effect of different design modifications in twisted tape on thermohydraulic performance of heat exchanger tube. Different inserts, i.e. Simple Twisted tape (STT), Double V-Cut Twisted Tape (DVCTT) and Perforated Double V-Cut Twisted Tape (PDVCTT), of varying twist ratio (TR) 3, 4 and 5 are considered for the investigation. Further design modification such as V-cut with width of cut (wc) 5 mm, depth of cut (dc) 4 mm, and perforation of 5 mm diameter is produced in twisted tape. Water is used as the working fluid for the study. Data pertaining to Nusselt number and friction factor is collected for the analysis in turbulent region where Reynolds number varied from 4000 to 16,000. Maximum enhancement in Nusselt number and friction factor is recorded 2.44 times and 3.71 times of plain tube respectively at Re = 4000 in case of TR = 3. Further PDVCTT leads to maximum decrement in Nusselt number and friction factor 3.83% and 27.35% when compared with DVCTT. Maximum thermal performance obtained is 1.71 in case of PDVCTT with TR of 3 at Re = 4000. [ABSTRACT FROM AUTHOR]

Copyright of Duzce University Journal of Science & Technology is the property of Duzce University Journal of Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Heat exchanger (HE) is an instrument that facilitates the operation of HE between two fluids that are at various temperatures. Double-pipe HEs are used in many organizations because of their low installation, design, maintenance costs, flexibility, and their suitability for high pressure applications. Heat transfer (HT) augmentation techniques (passive, active or compound techniques) are used in heat exchangers to reduce the HT surface area, to increase HT capacity and to reduce pumping power. Passive augmentation techniques are much cheaper and do not involve any external power input. They aim to improve the effective surface area, the residence time of the HT fluid and its thermal conductivity by the usage of nanofluids. Nanofluids are used for cooling applications in organizations, transportation, nuclear reactors, electrical and electronic devices and for biomedical applications. Hybrid nanofluids have higher thermal conductivity, low PD and frictional losses and pumping power as compared to the mono nanofluids. In this present work, experiments are conducted in a double pipe HE using TiO2, and SiC-water nanofluids by varying the volume concentration and cold fluid mass flow rate ranging from 17.5 to 34.5 lpm by making constant hot fluid mass flow rate. Further, experiments are conducted using TiO2–SiC/water hybrid nanofluids. Influence of nano and hybrid nanofluids on the overall HTC and friction factor are experimentally investigated. From the experiments, TiO2–SiC/water hybrid nanofluid with nanoparticle ratio TiO2:SiC = 1:2 is found to be optimum as the heat transfer enhancement is more with less improvement in friction factor. The overall heat transfer, and friction factor enhancement is 22.92 %, and 11.20 % higher respectively when compared with base fluid for TiO2:SiC = 1:2. [ABSTRACT FROM AUTHOR]

Helically coiled pipes are widely used in many industrial and engineering applications because of their compactness, larger heat transfer area per unit volume and higher efficiency in heat and mass transfer compared to other pipe geometries. They are commonly encountered in heat exchangers, steam generators in power plants and chemical reactors. The most notable feature of flow in helical pipes is the secondary flow (i.e., the cross-sectional circulatory motion) caused by centrifugal forces due to the curvature. Other important features are the stabilization effects of turbulent flow and the higher Reynolds number at which the transition from a laminar to a turbulent state occurs compared to straight pipes. A survey of the open literature on helical pipe flows shows that a good deal of experimental and theoretical work has been conducted to derive appropriate correlations to predict frictional pressure losses under laminar and turbulent conditions as well as to study the dependence of the flow characteristics and heat transfer capabilities on the Reynolds number, the Nusselt number and the geometrical parameters of the helical pipe. Despite the progress made so far in understanding the flow and heat transfer characteristics of helical pipe flow, there is still much work to be completed to address the more complex problem of multiphase flows and the impact of pipe deformation and corrugation on single- and multiphase flow. The aim of this paper is to provide a review on the state-of-the-art experimental and theoretical research concerning the flow in helically coiled pipes. [ABSTRACT FROM AUTHOR]

The heat transfer, friction and exergy loss of a square duct with combined circular and truncated rectangular ribs are analyzed using computational fluid dynamics. The study is focused on the effect of rib arrangements on the flow and heat transfer performance. The analysis is carried out with six truncated rib angles varying between 15° and 90° and Re range of 12000 -- 43000. The heat transfer is maximum in the middle part of the duct for 30° and 45° rib angles along span wise direction. The position of wake region is highly dependent on separation point over the circular rib as wake moves away radially from the axis of the duct for rib angles of 60°, 75° and 90°. The turbulent flow structures in large scale originates from side wall have marked effect on the heat transfer for the rib angles of 60°, 75° and 90° and with nearly with equal intensity for 15°, 30° and 45° rib angles. The exergy loss associated with friction is higher for 60° rib angle. While the normalized friction factor obtained with Fanning's equation varied between 1.8 and 4.2 and thermal hydraulic performance varied between 0.2 and 1.3 for the range of reexamined. [ABSTRACT FROM AUTHOR]

In this study, the flow and heat transfer characteristics of microencapsulated phase change material (MPCM) slurry were experimentally investigated using a newly designed helical coil heat transfer device. The conventional helical coil has been structurally modified with passive enhancement features aiming to further promote fluid mixing. Specifically, 360° plastic tubing with or without wire coil inserts was added after each 180° of the main helical loop to enhance fluid mixing and improve the overall thermal performance of the device. Pressure drop and heat transfer experiments with MPCM slurry were conducted under turbulent flow and constant heat flux conditions. A new friction factor and Nusselt number correlations for MPCM slurry in helical coils with reversed loops and wire coil inserts are proposed. Experimental results show that the structural modifications did enhance the heat transfer performance of MPCM slurry. The experimental results revealed that the phase change process of MPCM considerably enhanced the heat transfer rate of MPCM slurry. Furthermore, the use of reversed loops and wire coil inserts led to better fluid mixing within the coil, resulting in improved convective heat transfer of the MPCM slurry. [ABSTRACT FROM AUTHOR]

This numerical investigation is made to estimate the effect of Al2O3 and Cu nanofluids on heat transfer rate, friction factor and thermal performance factor of a shell and tube heat exchanger. Mass flow rates of shell side (water) fluid are varied. Water based nanofluids are used inside the tubes with 0.01, 0.03, and 0.05% volume concentrations of Al2O3 and Cu nanofluids. Nusselt number obtained from the present investigation is compared with Dittus–Bolter equation and Pongjet Pomvonge et al. and found to be in good agreement with a maximum deviation of 3%. The Nusselt number of the dispersed nanofluids increased with the increase of nanofluids volume concentrations and shell side mass flow rate. In this study, maximum enhancement in Nusselt number is 7.50%, 8.65%, and 9.61% for Al2O3, and 1.46%, 2.23%, and 3.18% for Cu nanofluid respectively at 0.01, 0.03, and 0.05% volume concentrations were compared to base fluid as water. Friction factor is highest by 58.00% at 0.05% volume concentration of Cu/H2O nanofluid when relate to Al2O3/H2O nanofluid. Thermal Enhancement factor achieved is highest for Al2O3/H2O nanofluid. [ABSTRACT FROM AUTHOR]