Stefan blowing effect on bioconvective flow of nanofluid over a solid rotating stretchable disk

A mathematical model for the unsteady forced convection over rotating stretchable disk in nanofluid containing microorganisms and taking into account Stefan blowing effect is presented theoretically and numerically.Appropriate transfonnations are used to transform the governing boundary layer equations into non-linear ordinary differential equations,before being solved numerically using the Runge-Kutta-Fehlberg method.The effect of the governing parameters on the dimensionless velocities,temperature,nanoparticle volume fraction(concen­tration),density of motile microorganisms as well as on the local skin friction,local Nusselt,Sherwood number and motile microorganisms numbers are thoroughly examined via graphs.It is observed that the Stefan blowing increases the local skin friction and reduces the heat transfer,mass transfer and microorganism transfer rates.The numerical results are in good agreement with those obtained from previous literature.Physical quantities results from this investigation show that the effects of higher disk stretching strength and suction case provides a good medium to enhance the heat,mass and microorganisms transfer compared to blowing case.

Numerical solution of thermo-solutal mixed convective slip flow from a radiative plate with convective boundary condition

A mathematical model for mixed convective slip flow with heat and mass transfer in the presence of thermal radiation is presented. A convective boundary condition is included and slip is simulated via the hydrodynamic slip parameter. Heat generation and absorption effects are also incorporated. The Rosseland diffusion flux model is employed. The governing partial differential conservation equations are reduced to a system of coupled, ordinary differential equations via Lie group theory method. The resulting coupled equations are solved using shooting method. The influences of the emerging parameters on dimensionless velocity, tempera- ture and concentration distributions are investigated. Increasing radiative-conductive parameter accelerates the boundary layer flow and increases temperature whereas it depresses concentration. An elevation in convection-conduction parameter also accelerates the flow and temperatures whereas it reduces concentrations. Velocity near the wall is considerably boosted with increasing momentum slip parameter although both temperature and concentration boundary layer thicknesses are decreased. The presence of a heat source is found to increase momentum and thermal boundary layer thicknesses but reduces concentration boundary layer thickness. Excelle- nt correlation of the numerical solutions with previous non-slip studies is demonstrated. The current study has applications in bio- reactor diffusion flows and high-temperature chemical materials processing systems.

Melting and second order slip effect on convective flow of nanofluid past a radiating stretching/shrinking sheet

A mathematical model is presented for forced convective slip flow of a nanofluid past a radiating stretching/shrinking sheet.Melting boundary condition is taken into account.The nanofluid model involves the Brownian motion and thermophoresis effects.Lie group transformation is used to the transport equations as well as the boundary conditions to develop the similarity equations,before being solved numerically using the Runge-Kutta-Fehlberg fourth-fifth order numerical method.To show the effects of the controlling parameters on the dimensionless velocity,temperature,nanoparticle volume fraction,skin friction factor,local Nusselt,and local Sherwood numbers,numerical results are presented both in graphical and tabular forms.It is found that the friction factor decreases with slip and melting parameters for both stretching/shrinking sheets.It is also found that the Nusselt number decreases with the first order slip while it increases with melting and radiation parameters in both cases.Also,the Sherwood number decreases with the melting parameter both for radiating and non-radiating stretching/shrinking sheets.An excellent agreement is found between the present numerical results and published results.