Mixed convective slip flow of hybrid nanofluid (MWCNTs + Cu + Water), nanofluid (MWCNTs + Water) and base fluid (Water): a comparative investigation

Author(s):  
K. Muhammad ◽  
T. Hayat ◽  
A. Alsaedi ◽  
B. Ahmad ◽  
S. Momani
2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
S. Sindhu ◽  
B.J. Gireesha

Purpose Thermal features of hybrid nanoliquid consist of Cu–Ti, CuO–TiO2 and C71500–Ti6Al4V/H2O as hybrid mixtures of nano-sized particles in a base fluid through a microchannel are inspected. In this study, flow model of Darcy–Forchheimer is hired to examine the flow of hybrid composition. Design/methodology/approach The equations which delineate the physical occurrence of the flow are resolved via Runge–Kutta–Fehlberg scheme united through shooting procedure. Findings It is established that flow velocity of hybrid nano composition satisfies the identity U_(CuO-TiO2/water)>U_(Cu–Ti/water)>U_(C71500–Ti6Al4V/water). Originality/value Hybrid nanofluid flow of Cu–Ti, CuO–TiO2 and C71500–Ti6Al4V/H2O hybrid mixtures in a base fluid through a microchannel are inspected.


Fluids ◽  
2021 ◽  
Vol 6 (4) ◽  
pp. 138
Author(s):  
Ali Rehman ◽  
Zabidin Salleh

This paper analyses the two-dimensional unsteady and incompressible flow of a non-Newtonian hybrid nanofluid over a stretching surface. The nanofluid formulated in the present study is TiO2 + Ag + blood, and TiO2 + blood, where in this combination TiO2 + blood is the base fluid and TiO2 + Ag + blood represents the hybrid nanofluid. The aim of the present research work is to improve the heat transfer ratio because the heat transfer ratio of the hybrid nanofluid is higher than that of the base fluid. The novelty of the recent work is the approximate analytical analysis of the magnetohydrodynamics mixed non-Newtonian hybrid nanofluid over a stretching surface. This type of combination, where TiO2+blood is the base fluid and TiO2 + Ag + blood is the hybrid nanofluid, is studied for the first time in the literature. The fundamental partial differential equations are transformed to a set of nonlinear ordinary differential equations with the guide of some appropriate similarity transformations. The analytical approximate method, namely the optimal homotopy analysis method (OHAM), is used for the approximate analytical solution. The convergence of the OHAM for particular problems is also discussed. The impact of the magnetic parameter, dynamic viscosity parameter, stretching surface parameter and Prandtl number is interpreted through graphs. The skin friction coefficient and Nusselt number are explained in table form. The present work is found to be in very good agreement with those published earlier.


2018 ◽  
Vol 67 ◽  
pp. 03057 ◽  
Author(s):  
Wayan Nata Septiadi ◽  
Ida Ayu Nyoman Titin Trisnadewi ◽  
Nandy Putra ◽  
Iwan Setyawan

Nanofluid is a liquid fluid mixture with a nanometer-sized solid particle potentially applied as a heat transfer fluid because it is capable of producing a thermal conductivity better than a base fluid. However, nanofluids have a weakness that is a high level of agglomeration as the resulting conductivity increases. Therefore, in this study, the synthesis of two nanoparticles into the base fluid called hybrid nanofluids. This study aims to determine the effect of nanoparticle composition on the highest thermal conductivity value with the lowest agglomeration value. This research was conducted by dispersing Al2O3-TiO2 nanoparticles in water with volume fraction of 0.1%, 0.3%, 0.5%, 0.7% in the composition of Al2O3-TiO2 ratio of 75%:25%, 50%:50%, 25%:75%. The synthesis was performed with a magnetic stirrer for 30 minutes. The tests were carried out in three types: thermal conductivity testing with KD2, visual agglomeration observation and absorbance measurements using UV-Vis, wettability testing with HSVC tools and Image applications. The test results showed that the ratio composition ratio of 75% Al2O3-25% TiO2 with a volume fraction of 0.7% resulted in an increase in optimum thermal conductivity with the best wettability and the longest agglomeration level.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
M. C. Mbambo ◽  
M. J. Madito ◽  
T. Khamliche ◽  
C. B. Mtshali ◽  
Z. M. Khumalo ◽  
...  

Abstract We report on the synthesis and thermal conductivity of gold nanoparticles (AuNPs) decorated graphene nanosheets (GNs) based nanofluids. The GNs-AuNPs nanocomposites were synthesised using a nanosecond pulsed Nd:YAG laser (wavelength = 1,064 nm) to ablate graphite target followed by Au in ethylene glycol (EG) base fluid to obtain GNs-AuNPs/EG hybrid nanofluid. The characterization of the as-synthesised GNs-AuNPs/EG hybrid nanofluid confirmed a sheet-like structure of GNs decorated with crystalline AuNPs with an average particle diameter of 6.3 nm. Moreover, the AuNPs appear smaller in the presence of GNs which shows the advantage of ablating AuNPs in GNs/EG. The thermal conductivity analysis in the temperature range 25–45 °C showed that GNs-AuNPs/EG hybrid nanofluid exhibits an enhanced thermal conductivity of 0.41 W/mK compared to GNs/EG (0.35 W/mK) and AuNPs/EG (0.39 W/mK) nanofluids, and EG base fluid (0.33 W/mK). GNs-AuNPs/EG hybrid nanofluid displays superior enhancement in thermal conductivity of up to 26% and this is due to the synergistic effect between AuNPs and graphene sheets which have inherent high thermal conductivities. GNs-AgNPs/EG hybrid nanofluid has the potential to impact on enhanced heat transfer technological applications. Also, this work presents a green synthesis method to produce graphene-metal nanocomposites for various applications.


2021 ◽  
Vol 25 (Spec. issue 2) ◽  
pp. 279-285
Author(s):  
Prvaeen Dadheech ◽  
Priyanka Agrawal ◽  
Anil Sharma ◽  
Kottakkaran Nisar ◽  
Sunil Purohit

In the present study Al2O3-SiO2-TiO2/C2H6O2 modified nanofluid flow over a stretching surface is considered with imposed inclined magnetic field. Three different suspended nanoparticles in a base fluid are considered in this next generation of hybrid nanofluid called as modified nanofluid. Ethanol glycol is taken as a base fluid with suspension of three nanoparticles of Al2O3, SiO2, and TiO2. The mathematical model of the flow is encountered by Runga-Kutta fourth order method using appropriate similarity transformations. As a key result it is observed that the capacity of heat transportation of modified nanofluid is higher as compared with nanofluids and hybrid nanofluids. Numerical solutions with graphical representation are presented. With increased inclined angle, parameter of magnetic field, and volume friction parameter a decrement in velocity field has been noticed for modified nanofluid.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Saeed Dinarvand ◽  
Mohammadreza Nademi Rostami ◽  
Ioan Pop

Abstract In this study, we are going to investigate semi-analytically the steady laminar incompressible two-dimensional boundary layer flow of a TiO2-CuO/water hybrid nanofluid over a static/moving wedge or corner that is called Falkner-Skan problem. A novel mass-based approach to one-phase hybrid nanofluid model that suggests both first and second nanoparticles as well as base fluid masses as the vital inputs to obtain the effective thermophysical properties of our hybrid nanofluid, has been presented. Other governing parameters are moving wedge/corner parameter (λ), Falkner-Skan power law parameter (m), shape factor parameter (n) and Prandtl number (Pr). The governing partial differential equations become dimensionless with help of similarity transformation method, so that we can solve them numerically using bvp4c built-in function by MATLAB. It is worthwhile to notice that, validation results exhibit an excellent agreement with already existing reports. Besides, it is shown that both hydrodynamic and thermal boundary layer thicknesses decrease with the second nanoparticle mass as well as Falkner-Skan power law parameter. Further, we understand our hybrid nanofluid has better thermal performance relative to its mono-nanofluid and base fluid, respectively. Moreover, a comparison between various values of nanoparticle shape factor and their effect on local heat transfer rate is presented. It is proven that the platelet shape of both particles (n1 = n2 = 5.7) leads to higher local Nusselt number in comparison with other shapes including sphere, brick and cylinder. Consequently, this algorithm can be applied to analyze the thermal performance of hybrid nanofluids in other different researches.


Author(s):  
S. Ahmad ◽  
Samreen Sheriff ◽  
Aisha Anjum ◽  
M. Farooq

The utility of convergent/divergent channel driven flow to improve the effectiveness of heat transport rate in industrial and engineering systems is diverse. This motivates us to disclose hybrid nanofluid flow features through non-parallel walls under hydro-magnetic aspect. The modified Darcian (Darcy–Forchheimer) expression is utilized for formulation. Reflection of improved Darcian form modifies the expression of velocity via square of velocity term. The effects of temperature jump and viscous dissipation are implemented in energy expression. Additionally, the slip flow phenomenon under the stretching/shrinking characteristics is studied. The analysis is carried out under the theory of boundary layer. Significant variables are implemented to acquire the dimensionless mathematical expressions. Dimensionless problem is tackled through a well-known homotopy technique. To observe the upshots of numerous pertinent parameters upon non-dimensional profiles of velocity and temperature, the graphs are plotted for both convergent/divergent channels. The heat transfer rate as well as drag force is also analyzed. In this study, it is concluded that temperature field rises in both divergent/convergent channels for dominant thermal slip parameter. Moreover, inertia parameter effects are seen weaker in converging channel for the velocity profile, while opposite trend is observed for diverging channel.


2021 ◽  
pp. 2150342
Author(s):  
P.-Y. Xiong ◽  
M. Ijaz Khan ◽  
R. J. Punith Gowda ◽  
R. Naveen Kumar ◽  
B. C. Prasannakumara ◽  
...  

This investigation is about hybrid nanofluid flowing over a sheet. We considered two-dimensional Darcy–Forchheimer flow of different hybrid nanofluids with the influence of uniform heat source sink and nonlinear thermal radiation. Different nanoparticles can be used to improve the thermal conductivity of a liquid. A study comparing the various hybrid nanofluids to nanofluid is considered. Here, we have selected manganese Zinc ferrite and Nickel Zinc ferrite as nanoparticles with kerosene oil and engine oil as carrier liquids. Suitable similarity transformations are used to construct the required ordinary differential equations. The influence of several non-dimensional parameters on velocity and thermal gradients is analyzed through graphs. Also, entropy generation is computed and analyzed through graph for different involved parameters. Here, we observed that [Formula: see text]–[Formula: see text]–[Formula: see text]–[Formula: see text] had lower velocity when compared to other two solutions. The entropy generation and Bejan number are high in [Formula: see text]–[Formula: see text]–[Formula: see text] when compared to [Formula: see text]–[Formula: see text]–[Formula: see text]–[Formula: see text] and [Formula: see text]–[Formula: see text]–[Formula: see text] and increase in heat generation parameter increases the rate of heat transfer.


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