Heat Transfer In Stagnation-point Flow Research Articles

Numerical study of melting heat transfer in stagnation-point flow of hybrid nanomaterial (MWCNTs+Ag+kerosene oil)

PurposeThe purpose of this study is to analyze hybrid nanofluid (MWCNTs+Ag+Kerosene oil) over a stretched cylinder. Flow analysis is carried out in presence of stagnation-point. Features of heat transport are examined via melting conditions.Design/methodology/approachGoverned expression (partial differential equations) for flow and heat transfer are transmitted into ordinary differential equations (ODEs) via applying adequate transformations. For solutions development shooting method (bvp4c) is used on these non-linear coupled ODEs.FindingsComparative observation among hybrid nanofluid (MWCNTs+Ag+Kerosene oil), basefluid (kerosene oil) and nanofluid (MWCNTs+Kerosene oil) are performed. Influences of physical parameters on heat transfer rate, velocity, skinfriction coefficient and temperature are visualized graphically. Higher values nanoparticle volume fractions, curvature parameter, melting parameter and velocity ratio parameter lead to intensification in the velocity profile. The temperature of the fluid reduces with higher values nanoparticle volume fractions, curvature parameter and melting parameter. The surface friction coefficient is minimized via a higher melting parameter and velocity ratio parameter. Heat transmission rate intensifies with velocity ratio parameter, nanoparticle volume friction and curvature parameter while it reduces gradually with larger melting parameter. During comparative study performance of hybrid nanomaterial (MWCNTs+Ag+Kerosene oil) is outstanding and is proceeded by nanomaterial (MWCNTs+ Kerosene oil) and basefluid (kerosene oil).Originality/valueIn the presented study authors have analyzed the flow of hybrid nanomaterial (MWCNTs+Ag+Kerosene oil) by a stretching cylinder. The further cylinder is subjected to stagnation point and melting condition. The authors believe that all the consequences of the presented study and numerical technique (bvp4c) are original and not published before.

Heat transfer in stagnation-point flow of a Jeffrey fluid past a lubricated surface

In this manuscript, heat transfer in flow of Jeffrey fluid past a lubricated surface near a stagnation point is considered. A shear-thinning (power-law) fluid is utilized for the lubrication purpose. The interfacial conditions are developed by applying the continuity of velocity and shear stress of Jeffrey and power-law fluids. Similarity solutions are obtained by selecting power-law index as 0.5. Approximate numerical results are achieved using Keller box scheme. Effects of involved parameters in the presence of lubrication are expressed by graphs and tables. It is found that the lubricant enhances the effects of the retardation parameter while opposes the ratio parameter effects. The temperature is reduced in the presence of the lubricant.

Similarity Solution of Unaxisymmetric Heat Transfer in Stagnation-Point Flow on a Cylinder With Simultaneous Axial and Rotational Movements

Similarity solution of unaxisymmetric heat transfer of an unsteady viscous flow in the vicinity of an axisymmetric stagnation point of an infinite circular cylinder with simultaneous axial and rotational movement along with transpiration Uo is investigated when the angular velocity, axial velocity, and wall temperature or wall heat flux vary arbitrarily with time. The impinging free stream is steady and with a strain rate of k¯. The results presented are found by numerical integration. The local coefficient of heat transfer (Nusselt number) is found to be independent of time and place, though the cylinder wall temperature or wall heat flux are functions of both time and place.

Heat transfer in stagnation-point flow towards a stretching sheet

Steady two-dimensional stagnation-point flow of an incompressible viscous fluid over a flat deformable sheet is investigated when the sheet is stretched in its own plane with a velocity proportional to the distance from the stagnation-point. It is shown that for a fluid of small kinematic viscosity, a boundary layer is formed when the stretching velocity is less than the free stream velocity and an inverted boundary layer is formed when the stretching velocity exceeds the free stream velocity. Temperature distribution in the boundary layer is found when the surface is held at constant temperature and surface heat flux is determined.