Corrected second-order slip boundary condition for fluid flows in nanochannels

2010 ◽  
Vol 81 (6) ◽  
Author(s):  
Hongwu Zhang ◽  
Zhongqiang Zhang ◽  
Yonggang Zheng ◽  
Hongfei Ye
Keyword(s):  
Boundary Condition ◽  
Fluid Flows ◽  
Slip Boundary Condition ◽  
Second Order ◽  
Slip Boundary

Experimental and Numerical Studies on Gas Flow Through Silicon Microchannels

2017 ◽  
Vol 139 (8) ◽  
Author(s):  
K. Srinivasan ◽  
P. M. V. Subbarao ◽  
S. R. Kale
Keyword(s):  
Boundary Condition ◽  
Gas Flow ◽  
Stokes Equations ◽  
Pressure Ratio ◽  
Flow Characteristics ◽  
Slip Boundary Condition ◽  
Second Order ◽  
Navier Stokes ◽  
Slip Boundary ◽  
Aspect Ratios

The present work investigates the extension of Navier–Stokes equations from slip-to-transition regimes with higher-order slip boundary condition. To achieve this, a slip model based on the second-order slip boundary condition was derived and a special procedure was developed to simulate slip models using FLUENT®. The boundary profile for both top and bottom walls was solved for each pressure ratio by the customized user-defined function and then passed to the FLUENT® solver. The flow characteristics in microchannels of various aspect ratios (a = H/W = 0.002, 0.01, and 0.1) by generating accurate and high-resolution experimental data along with the computational validation was studied. For that, microchannel system was fabricated in silicon wafers with controlled surface structure and each system has several identical microchannels of same dimensions in parallel and the processed wafer was bonded with a plane wafer. The increased flow rate reduced uncertainty substantially. The experiments were performed up to maximum outlet Knudsen number of 1.01 with nitrogen and the second-order slip coefficients were found to be C1 = 1.119–1.288 (TMAC = 0.944–0.874) and C2 = 0.34.

On the no-slip boundary condition

1973 ◽  
Vol 59 (4) ◽  
pp. 707-719 ◽  
Author(s):  
S. Richardson
Keyword(s):  
Boundary Condition ◽  
Simple Model ◽  
Viscous Fluid ◽  
Viscous Dissipation ◽  
Solid Surface ◽  
Fluid Flows ◽  
Slip Boundary Condition ◽  
Rough Wall ◽  
Microscopic Scale ◽  
Slip Boundary

It has been argued that the no-slip boundary condition, applicable when a viscous fluid flows over a solid surface, may be an inevitable consequence of the fact that all such surfaces are, in practice, rough on a microscopic scale: the energy lost through viscous dissipation as a fluid passes over and around these irregularities is sufficient to ensure that it is effectively brought to rest. The present paper analyses the flow over a particularly simple model of such a rough wall to support these physical ideas.

scholarly journals Unified slip boundary condition for fluid flows

2016 ◽  
Vol 94 (2) ◽  
Author(s):  
Joseph John Thalakkottor ◽  
Kamran Mohseni
Keyword(s):  
Boundary Condition ◽  
Fluid Flows ◽  
Slip Boundary Condition ◽  
Slip Boundary

The effect of second order slip condition on MHD nanofluid flow around a semi-circular cylinder

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jiahui Cao ◽  
Jing Zhu ◽  
Xinhui Si ◽  
Botong Li
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Boundary Condition ◽  
Circular Cylinder ◽  
Volume Fraction ◽  
Velocity Slip ◽  
Slip Boundary Condition ◽  
Second Order ◽  
Ansys Fluent ◽  
Slip Boundary

Abstract Steady forced convection of non-Newtonian nanofluids around a confined semi-circular cylinder subjected to a uniform magnetic field is carried out using ANSYS FLUENT. The numerical solution is obtained using the finite volume method. The user-defined scalar (UDS) is used for the first time to calculate the second order velocity slip boundary condition in semi-circular curved surface and the calculated results are compared with those of the first order velocity slip boundary condition. Besides, the effects of volume fraction, size, type of nanoparticles and magnetic field strength on heat transfer are studied. The present study displays that adding nanoparticles in non-Newtonian fluids significantly enhances heat transfer. In addition, it is observed that the heat transfer rate decreases first and then increases with the increase of Hartmann number. The effects of blocking rate on Nusselt number, wake length and heat transfer effect are shown in the form of graphs or tables.

Slip mechanisms in complex fluid flows

Soft Matter ◽  
2015 ◽  
Vol 11 (40) ◽  
pp. 7851-7856 ◽  
Author(s):  
Savvas G. Hatzikiriakos
Keyword(s):  
Boundary Condition ◽  
Fluid Mechanics ◽  
Polymer Solutions ◽  
Polymer Melts ◽  
Complex Fluids ◽  
Fluid Flows ◽  
Slip Boundary Condition ◽  
Slip Boundary ◽  
Complex Fluid

The classical no-slip boundary condition of fluid mechanics is not always a valid assumption for the flow of several classes of complex fluids including polymer melts, their blends, polymer solutions, microgels, glasses, suspensions and pastes.

scholarly journals Unsteady Rotational Motion of a Slip Spherical Particle in a Viscous Fluid

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
E. A. Ashmawy
Keyword(s):  
Boundary Condition ◽  
Fluid Flow ◽  
Angular Velocity ◽  
Viscous Fluid ◽  
Spherical Particle ◽  
Rotational Motion ◽  
Fluid Flows ◽  
Slip Boundary Condition ◽  
Viscous Fluid Flow ◽  
Slip Boundary

The unsteady rotational motion of a slip spherical particle with a nonuniform angular velocity in an incompressible viscous fluid flow is discussed. The technique of Laplace transform is used. The slip boundary condition is applied at the surface of the sphere. A general formula for the resultant torque acting on the surface of the sphere is deduced. Special fluid flows are considered and their results are represented graphically.

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