Numerical investigation of velocity slip and temperature jump effects on unsteady flow over a stretching permeable surface

2017 ◽  
Vol 132 (2) ◽  
Author(s):  
E. Hosseini ◽  
G. B. Loghmani ◽  
M. Heydari ◽  
M. M. Rashidi
Keyword(s):  
Unsteady Flow ◽  
Numerical Investigation ◽  
Temperature Jump ◽  
Velocity Slip ◽  
Permeable Surface

scholarly journals Thermal radiation effects on the onset of unsteadiness of fluid flow in vertical microchannel filled with highly absorbing medium

2016 ◽  
Vol 20 (5) ◽  
pp. 1585-1596 ◽  
Author(s):  
Jamalabadia Abdollahzadeh ◽  
Hyun Park ◽  
Chang Lee
Keyword(s):  
Reynolds Number ◽  
Nusselt Number ◽  
Thermal Radiation ◽  
Skin Friction ◽  
Temperature Jump ◽  
Velocity Slip ◽  
Radiation Parameter ◽  
Absorbing Medium ◽  
Grashof Number ◽  
Temperature Parameter

This study presents the effect of thermal radiation on the steady flow in a vertical micro channel filled with highly absorbing medium. The governing equations (mass, momentum and energy equation with Rosseland approximation and slip boundary condition) are solved analytically. The effects of thermal radiation parameter, the temperature parameter, Reynolds number, Grashof number, velocity slip length, and temperature jump on the velocity and temperature profiles, Nusselt number, and skin friction coefficient are investigated. Results show that the skin friction and the Nusselt number are increased with increase in Grashof number, velocity slip, and pressure gradient while temperature jump and Reynolds number have an adverse effect on them. Furthermore, a criterion for the flow unsteadiness based on the temperature parameter, thermal radiation parameter, and the temperature jump is presented.

Algebraic solutions of flow and heat for some nanofluids over deformable and permeable surfaces

2017 ◽  
Vol 27 (10) ◽  
pp. 2259-2267 ◽  
Author(s):  
Mustafa Turkyilmazoglu
Keyword(s):  
Heat Transfer ◽  
Design Methodology ◽  
Temperature Jump ◽  
Volume Fraction ◽  
Velocity Slip ◽  
Jump Conditions ◽  
Content Type ◽  
Layer Flow ◽  
Working Out ◽  
Algebraic Solutions

Purpose This paper aims to working out exact solutions for the boundary layer flow of some nanofluids over porous stretching/shrinking surfaces with different configurations. To serve to this aim, five types of nanoparticles together with the water as base fluid are under consideration, namely, Ag, Cu, CuO, Al2O3 and TiO2. Design/methodology/approach The physical flow is affected by the presence of velocity slip as well as temperature jump conditions. Findings The knowledge on the influences of nanoparticle volume fraction on the practically significant parameters, such as the skin friction and the rate of heat transfer, for the above considered nanofluids, is easy to gain from the extracted explicit formulas. Originality/value Particularly, formulas clearly point that the heat transfer rate is not only dependent on the thermal conductivity of the material but it also highly relies on the heat capacitance as well as the density of the nanofluid under consideration.

Erratum: "Conical Nozzle Flow with Velocity Slip and Temperature Jump"

AIAA Journal ◽  
1969 ◽  
Vol 7 (2) ◽  
pp. 0384a-0384a
Author(s):  
JAMES C. WILLIAMS
Keyword(s):  
Temperature Jump ◽  
Velocity Slip ◽  
Nozzle Flow ◽  
Conical Nozzle

EFFECTS OF THERMAL CREEP ON COOLING OF MICROFLOWS IN SHORT MICROCHANNELS WITH CONSTANT WALL TEMPERATURE

2012 ◽  
Vol 23 (11) ◽  
pp. 1250072 ◽  
Author(s):  
ALI AMIRI-JAGHARGH ◽  
HAMID NIAZMAND ◽  
METIN RENKSIZBULUT
Keyword(s):  
Wall Temperature ◽  
Temperature Jump ◽  
Control Volume ◽  
Velocity Slip ◽  
Temperature Gradients ◽  
Thermal Creep ◽  
Inlet Temperature ◽  
Constant Wall Temperature ◽  
Aspect Ratios ◽  
Wide Range

Fluid flow and heat transfer in the entrance region of rectangular microchannels of various aspect ratios are numerically investigated in the slip-flow regime with particular attention to thermal creep effects. Uniform inlet velocity and temperature profiles are prescribed in microchannels with constant wall temperature. An adiabatic section is also employed at the inlet of the channel in order to prevent unrealistically large axial temperature gradients due to the prescribed uniform inlet temperature as well as upstream diffusion associated with low Reynolds number flows. A control-volume technique is used to solve the Navier–Stokes and energy equations which are accompanied with appropriate velocity slip and temperature jump boundary conditions at the walls. Despite the constant wall temperature, axial and peripheral temperature gradients form in the gas layer adjacent to the wall due to temperature jump. The simultaneous effects of velocity slip, temperature jump and thermal creep on the flow and thermal patterns along with the key flow parameters are examined in detail for a wide range of cross-sectional aspect ratios, and Knudsen and Reynolds numbers. Present results indicate that thermal creep effects influence the flow field and the temperature distribution significantly in the early section of the channel.

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