Study of thermal and hydrodynamic characteristics of water-nano-encapsulated phase change particles suspension in an annulus of a porous eccentric horizontal cylinder

Ghalambaz, Mohammad; Mehryan, S.A.M.; Mozaffari, Masoud; Zadeh, Seyed Mohsen Hashem; Pour, Mohsen Saffari

doi:10.1016/j.ijheatmasstransfer.2020.119792

Cited by 37 publications

(7 citation statements)

References 41 publications

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“…Currently, the free convective flow of a nanoencapsulated phase change material suspension in an eccentric annulus was numerically examined by Mehryan et al 30 Also, Ghalambaz et al 31 examined the hydrodynamic and thermal features of a suspension with water–nano‐encapsulated phase change material in an annulus of a porous eccentric horizontal cylinder. Furthermore, the entropy generation in the natural convection of water combined with nano‐sized particles having the encapsulated phase change material in a square enclosure with a solid triangular block was investigated by Zadeh et al 32 From their findings, it was revealed that the heat transfer rate can be improved by applying the phase change core of nanoparticles, and the generated entropy grows as the volume fraction of the nanocapsules increases.…”

Section: Introductionmentioning

confidence: 99%

Mixed convection hybrid nanofluids flow of MWCNTs–Al₂O₃/engine oil over a spinning cone with variable viscosity and thermal conductivity

Tulu

Ibrahim

2021

Heat Trans

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This work analyzed the effects of variable viscosity and thermal conductivity, with mixed convection, thermal radiation and viscous dissipation effects, on multiwalled carbon nanotubes (MWCNTs)–aluminum oxide (Al2O3)/engine oil hybrid nanofluid flow due to a vertically inverted spinning cone embedded in a porous medium. Using suitable similarity transformation, the boundary layer fluid flow governing equations are transformed into dimensionless systems of coupled nonlinear ordinary differential equations. Then, the solutions are obtained numerically employing the spectral relaxation method. The influences of involved parameters are examined, and the results are presented with graphs and tables. The obtained results disclose that both the tangential and azimuthal skin friction coefficients increase with increasing values of temperature‐dependent viscosity and mixed convection parameters. The local heat transfer rate reduces with increasing values of the Eckert number and variable thermal conductivity parameter, whereas it enhances with greater values of the thermal radiation parameter. Generally, hybrid nanofluids of (MWCNTs–Al2O3)/engine oil show better flow distributions with good stability of thermal properties than MWCNTs/engine oil and Al2O3/engine oil mono‐nanofluids.

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Section: Introductionmentioning

confidence: 99%

Mixed convection hybrid nanofluids flow of MWCNTs–Al₂O₃/engine oil over a spinning cone with variable viscosity and thermal conductivity

Tulu

Ibrahim

2021

Heat Trans

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“…Other investigations examined the installation of porous baffles in ducts. Abbasi [66] and Ho et al [67] inspected the influence of several aspect ratio ducts and various configurations of porous VGs. Their results suggested a powerful relationship between of the thermal exchange and the assigned parameters.…”

Section: Introductionmentioning

confidence: 99%

CFD-Based Simulation and Analysis of Hydrothermal Aspects in Solar Channel Heat Exchangers with Various Designed Vortex Generators

Salmi¹,

YounesMenni²,

Chamkha³

et al. 2021

Computer Modeling in Engineering &Amp; Sciences

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The hydrothermal behavior of air inside a solar channel heat exchanger equipped with various shaped ribs is analyzed numerically. The bottom wall of the exchanger is kept adiabatic, while a constant value of the temperature is set at the upper wall. The duct is equipped with a flat rectangular fin on the upper wall and an upstream V-shaped baffle on the lower wall. Furthermore, five hot wall-attached rib shapes are considered: trapezoidal, square, triangular pointing upstream (type I), triangular pointing downstream (type II), and equilateral-triangular (type III) cross sections. Effects of the flow rates are also inspected for various Reynolds numbers in the turbulent regime (1.2 × 10 4 -3.2 × 10 4 ). The highest performance (η) value is given for the II-triangular rib case in all Re values, while the square-shaped ribs show a significant decrease in the η along the achieved Re range. The η value at Re max is 2.567 for the II-triangular roughness case. Compared with the other simulated cases, this performance is decreased by about 3.768% in the case of I-triangular ribs, 15.249% in the case of III-triangular ribs, 20.802% in the case of trapezoidal ribs, while 27.541% in the case of square ribs, at the same Re max . Also, a comparison is made with air-heat exchangers that have non-rough walls and contain cross-shaped VGs presented previously, in order to highlight the effectiveness of the rough surface presence in the baffled and finned channels. The obtained results indicated that the triangular-shaped rib (type II) has the most significant hydrothermal behavior than the other cases. This indicates the necessity of roughness heat transfer surfaces for finned and baffled channels to improve significantly the performance of the air-heat exchangers they contain.

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“…Many experimental, analytical, and numerical studies on the melting and solidification of the PCM in encapsulated geometries have been reported in the literature by imposing constant temperature or heat flux at the encapsulation boundary and for a variety of encapsulation geometries such as spheres [24][25][26], rectangular containers [27][28][29][30], and horizontal [31][32][33] and vertical cylinders [34][35][36][37][38][39][40][41][42][43]. These studies provide a good understanding of the heat transfer and thermal storage characteristics of the encapsulated PCMs (EPCMs) under fixed temperature or heat flux boundary conditions.…”

Section: Introductionmentioning

confidence: 99%

Phase-Change Process Inside a Small-Radii Cylinder Subjected to Cyclic Convective Boundary Conditions: A Numerical Study

Kanani

Karmakar

Acharya

2021

Journal of Heat Transfer

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We numerically investigate the melting and solidi?cation behavior of phase change materials encapsulated in a small-radii cylinder subjected to a cyclic convective boundary condition (square wave). Initially, we explore the effect of the Stefan and Biot numbers on the non-dimensionalized time required (i.e. reference Fourier number Tref ) for a PCM initially held at Tcold to melt and reach the cross?ow temperature Thot. The increase in either Stefan or Biot number decreases Tref and can be predicted accurately using a correlation developed in this work. The variations of the PCM melt fraction, surface temperature, and heat transfer rate as a function of Fourier number are reported and analyzed for the above process. We further study the effect of the cyclic Fourier number on the periodic melting and freezing process. The melting or freezing front initiates at the outer periphery of the PCM and propagates towards the center. At higher frequencies, multiple two-phase interfaces are generated (propagating inward), and higher overall heat transfer is achieved as the surface temperature oscillates in the vicinity of the melting temperature, which increases the effective temperature difference driving the convective heat transfer.

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Study of thermal and hydrodynamic characteristics of water-nano-encapsulated phase change particles suspension in an annulus of a porous eccentric horizontal cylinder

Cited by 37 publications

References 41 publications

Mixed convection hybrid nanofluids flow of MWCNTs–Al₂O₃/engine oil over a spinning cone with variable viscosity and thermal conductivity

Mixed convection hybrid nanofluids flow of MWCNTs–Al₂O₃/engine oil over a spinning cone with variable viscosity and thermal conductivity

CFD-Based Simulation and Analysis of Hydrothermal Aspects in Solar Channel Heat Exchangers with Various Designed Vortex Generators

Phase-Change Process Inside a Small-Radii Cylinder Subjected to Cyclic Convective Boundary Conditions: A Numerical Study

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Study of thermal and hydrodynamic characteristics of water-nano-encapsulated phase change particles suspension in an annulus of a porous eccentric horizontal cylinder

Cited by 37 publications

References 41 publications

Mixed convection hybrid nanofluids flow of MWCNTs–Al2O3/engine oil over a spinning cone with variable viscosity and thermal conductivity

Mixed convection hybrid nanofluids flow of MWCNTs–Al2O3/engine oil over a spinning cone with variable viscosity and thermal conductivity

CFD-Based Simulation and Analysis of Hydrothermal Aspects in Solar Channel Heat Exchangers with Various Designed Vortex Generators

Phase-Change Process Inside a Small-Radii Cylinder Subjected to Cyclic Convective Boundary Conditions: A Numerical Study

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Mixed convection hybrid nanofluids flow of MWCNTs–Al₂O₃/engine oil over a spinning cone with variable viscosity and thermal conductivity

Mixed convection hybrid nanofluids flow of MWCNTs–Al₂O₃/engine oil over a spinning cone with variable viscosity and thermal conductivity