Non-Newtonian electromagnetic fluid flow through a slanted parabolic started Riga surface with ramped energy

The present study deals with the implications of non-Newtonian fluid via a slanted parabolic started surface with ramped energy. In addition, the characteristics of electrically conducting viscoelastic liquid moving across the Riga surface are investigated systematically, emphasized within the time-dependent concentration and temperature variations. The mathematical model is made possible by enforcing momentum and heat conservation principles in the format of partial differential equations (PDEs). Heat considerations are emphasized with respect to radiant heat influx. Similarity characteristics are leveraged to convert PDEs to ordinary differential equations. The Laplace transform method is used to find the exact solutions for the obtained differential configuration. The effect of flow on associated patterns is depicted graphically and with tables. Furthermore, fluctuation in relevant engineering parameters such as wall shear stress, temperature, and mass variability on the surface is measured. The range of parameters selected is as follows: $\psi [0.1-1]$, $Pr[0.71-10]$, $Sc[0.16-2.01]$, $Gr=Gc[5-20]$, $E[1-5]$, and $R[2-10]$. The analytical and numerical solutions are validated and in good agreement. It is worth reporting that the improved Hartmann number and thermal radiation values boost velocity dispersion and skin friction. As expected, respectively, energy and mass transfer rates are escalated with large values of Prandtl number and Schmidt number.     

Boundary layer flow and stability analysis of forced convection over a diverging channel with variable properties of fluids

The objective of the current study is to investigate the forced convection laminar boundary layer flow over a flat plate in a diverging channel with variable viscosity. The physical governing equations are converted to nondimensional partial differential equations (PDEs) using similarity transformation. The coupled PDEs with boundary constrains are solved numerically using quasilinearization technique. Computational results are given in terms of flow parameter $ϵ\left(0<ϵ<1\right)$, suction or injection A, and viscous dissipation parameter Ec. Stability analysis was conducted and the solutions were found to be stable for real values of $\gamma$. We found that variable Prandtl number with quasilinearization technique method gives smoothness of solution compared to fixed Prandtl number. This is shown graphically for different fluids in Section 5. Also, the significant effect of the suction/injection parameter $\left(A\right)$ on velocity, temperature profiles, skin friction, and heat transfer is observed.     

Thermohydraulic and entropy characteristics of Al2O3-water nanofluid in a ribbed interrupted microchannel heat exchanger

In this study, an interrupted microchannel heat sink with rib turbulators was studied for its thermohydraulic effectiveness and entropy generation in a compact space. The rib edges are modified to enhance the overall functioning of the system by reducing the pressure drop. The working fluid used was Al₂O₃-water nanofluid, and increasing the Reynolds number and nanoparticle concentration triggered a reduction in the heat sink's maximum temperature. These also offer a decrease in resistance to heat transfer, and there is an improvement in the evenness of the temperature of the interrupted microchannel heat sink, as regions with the likelihood of hot spot reduced drastically. At Re = 100, increasing the nanoparticle concentration from 0% to 4% enhanced the heat transfer coefficient by 38.41% for the interrupted microchannel heat sink-base (IMCH-B) configuration. Under similar conditions, the convective heat transfer coefficient for the interrupted microchannel heat sink-fillet (IMCH-F) increased by 43.69%. Furthermore, at 0.5% concentration, changing the Reynolds number from 100 to 700 augmented the heat transfer coefficient by 70.65%. Thus, the maximum temperature of the substrate's bottom surface was reduced by 53.83°C when the system was operated at Re = 700 and nanoparticle concentration of 4%. The IMCH-C also showed relatively close results at all observed volume fractions. For the IMCH-C, the maximum temperature of the bottom surface was reduced by 41.98°C at Re = 700 when compared with Re = 100% and 4% concentration. Although at high Reynolds numbers and concentrations, the pressure drops are higher, the performance enhancement criteria prove that the nanofluid is superior to water and the edge modifications show significant performance improvement. More importantly, the IMCH-F heat sink showed the optimum performance based on the performance evaluation criteria at Re = 300 and $\phi =2\%$ (ie, at this point, the heat transfer coefficient is maximum and the pressure drop is minimum). On the other hand, the optimal thermodynamic performance was observed at Re = 700 and $\phi =4\%$. The numerical results demonstrated a potential way to exploit nano-suspensions for thermal applications, especially for high-energy flux systems with compact space constraints.     

A mathematical simulation of unsteady MHD Casson nanofluid flow subject to the influence of chemical reaction over a stretching surface: Buongiorno's model

In this study, unsteady boundary layer flow with Casson nanofluid within the sight of chemical reaction toward a stretching sheet has been analyzed mathematically. The fundamental motivation behind the present examination is to research the influence of different fluid parameters, in particular, Casson fluid $\beta (0.2\le \beta \le 0.4)$, thermophoresis $Nt(0.5\le Nt\le 1.5)$, magnetohydrodynamic $M(3.0\le M\le 5.0)$, Brownian movement $Nb(0.5\le Nb\le 2.0)$, Prandtl numberty, unsteadiness parameter $A(0.10\le A\le 0.25)$, chemical reaction parameter $\gamma (0.1\le \gamma \le 0.8)$, and Schmidt number $Sc(1.0\le Sc\le 3.0)$ on nanoparticle concentration, temperature, and velocity distribution. The shooting procedure has been adopted to solve transformed equations with the assistance of Runge–Kutta Fehlberg technique. The impact of different controlling fluid parameters on flow, heat, and mass transportation are depicted in tabular form and are shown graphically. Additionally, values of skin friction coefficient, Nusselt number, and Sherwood number are depicted via tables. Present consequences of the investigation for Nusselt number are related with existing results in writing by taking $Nb=0$ and $Nt=0$ where results are finding by utilization of MATLAB programming. Findings of current research help in controlling the rate of heat and mass aspects to make the desired quality of final product aiding manufacturing companies and industrial areas.