Abstract:
In this research, the specification of 3-dimensional flow stagnation point of hybrid Nano fluids passing through circular cylinder with sinusoidal radius are analyzed. C2H6O2, H2O and Engine oil are used as an ordinary liquid, while nano-particles include SWCNT and MWCNT. Fluid stream is taken into account with/without considering the effect of thermal slippage. Higher order non-linear phrases are transformed to ordinary prime-order differential equations and then solved applying the Analytical Method (HPM) in Matlab-14 software. Graphical analysis of the impressive parameters like: Prandtl number, thermal slip parameter, CNTs volume fraction is precisely checked on the profiles of velocity and temperature for various carbon nano-tubes. Consequences display that: cooling process or heat transfer rate can be increased by employing smaller thermal slippage parameter. Further, due to the better thermal conductivity of SWCNT carbon nanotube, the temperature increase in these carbon nanotubes is more than that of MWCNT.
Keywords: Hybrid Nanofluids; Circular cylinder; SWCNT and MWCNT; Thermal slip; HPM method
Introduction:
Recent studies reveal that some carbon structures have very good thermal conductivity. Therefore, diverse studies have been carried out on the thermal properties of Nano fluids using carbon Nano structres such as graphite, single-walled carbon nano-tubes (SWCNT), multi-walled carbon nano-tubes (MWCNT), Nano-diamonds and graphene [1-8]. Carbon nano-tubes with only one graphene layer are called single-walled carbon nanotubes, while nanotubes with more than one graphene layer are described as multi-walled nanotubes that can slip into one another. The unique characteristics of these materials as a new form of carbon material include strength, hardness, adhesion, chemical stability, thermal conductivity and more interesting than all electrical conductivity, and they have many applications in microelectronics and Nano electronics, fuel storage, preparing flat panel display, constructional composite materials, anti-deposition paint, H2 storage, radar absorber coating, technical tissues, conductive plastics, improved lifetime batteries, super-capacitors, super strong fibers, biomass sensors for harmful gases, etc. Iijima [9] began investigating carbon nanotubes. Experimental research on MWCNT–H2O nanoliquid stream and heat transfer in the heat exchanger with cancellous media has been practiced out by Moradi et al. [10]. Application of retrievable carbon nanotube Nano fluids in solar desalination system is examined by Chen et al. [11]. In the similar paper, the influence of surfactants on the resistance and solar thermal sorption specifications of multi-walled carbon nanotubes Nano fluids is discussed by Choi et al. [12]. Selimefendigil and Öztop [13] investigated the MHD free convection of CNT-H2O nanoliquid in a cavity with a corrugated partition. Also, the use of carbon nanotube Nano fluid in increasing the efficiency of discharged tube solar collector studied by Mahbubul et al. [14]. Effect of magnetic and non-magnetic nanoparticles on mixed convection flow of a new thermal conductivity model with Cu-Fe3O4 hybrid nanoliquid over a straight stretching plate has been done by Hussanan et al. [15]. The output of this essay indicates that liquids based in SA should be used to attain high heat transfer rate. Some other essays about carbon nanotubes nano liquid are in references [16-20].
Hybrid nanofluids are potential fluids that offer better thermal efficiency and thermos-physical properties than basic heat transfer fluids (including mineral oils, water and ethylene glycol) and nanofluids with a single nanoparticle type. Hybrid nanofluid is a new fluid that is made by dispersing two different types of nanoparticles into the heat transfer base fluid. Researchers have shown that hybrid nanofluids can replace conventional coolers, especially fluids that operate at very high temperatures. Hybrid nanoliquid also has a large potential to maintain and absorb energy due to the unique and special structure of any nanoparticle. Another matter propounded in this essay is the tensile cylinder. Tensile cylinder is increasingly used in the laboratory to investigate the reaction between liquids and solid surfaces. This cylinder often works at high temperature gradients. Recent studies demonstrate the importance of this topic, for example: Numerical check on entropy generation during natural convection of hybrid nanoliquid in a sigmoid passage between straight elliptic cylinders has been done by Tayebi and Öztop [21]. Sundar et al. [22] discussed friction factor and turbulent heat transfer in a horizontal tube of Nano diamond-nickel hybrid Nano fluids flow. Impact of hybrid Nano fluids in solar thermal systems on the proficiency of parabolic trough gatherers is analyzed by Minea and Maghlany [23]. In the similar paper, Bellos and Tzivanidis [24] considered the mono and hybrid Nano fluids for thermal investigate of parabolic trough collector. Entropy generation analysis and heat transfer proficiency in a flat tube of hybrid Nano fluids is addressed by G. Huminic and A. Huminic [25]. Some other activities about hybrid Nano fluids and Nano fluids flow are in references [26-29].
In this research, the aim is to check the characteristics of 3-dimensional flow stagnation point of hybrid nano liquids passing through circular cylinder with sinusoidal radius. The flow regime is considered with both electromagnetic source and the effects of thermal slippage. The potent nonlinear systems calculations are offered using the analytical manner after non-dimensionalization. Plus, graphical analysis of the impressive parameters is precisely checked on the profiles of velocity and temperature for various carbon nano-tubes (SWCNT - MWCNT).
Mathematical formulation:
The 3-dimensional stream of hybrid nano fluids is considered as independent of time for a circular cylinder. The cylinder’s radius changes sinusoidally. It is substantial to note that at each point M, N and O (utmost and minim radius), there exists an immobility point. The W, V and U are the component of velocities along Z − path, Y – path and X – path respectively. Following us have [30]: