A numerical simulation of micro Poiseuille flow has performed for rarefied and compressible flow at slip flow regimes. The wall roughness is simulated in two cases with triangular microelements and random micro peaks distributed on wall surfaces to study the effects of roughness shape and distribution on flow field. Two values of Mach and Knudsen numbers have used to investigate the effects of ...

A fundamental problem in heat transfer is the convective cooling of the heated walls of a channel. We find steady two-dimensional (2D) flows that maximize the heat removed from fixed-temperature walls for a given rate of energy used to drive the flow, Pe (Pe is the Peclet number, a dimensionless flow speed). For parabolic (Poiseuille) flow, the heat transfer scales as Pe. Starting from Poiseuil...

A new universal theory for flow instability and turbulent transition is proposed in this study. Flow instability and turbulence transition have been challenging subjects for fluid dynamics for a century. The critical condition of turbulent transition from theory and experiments differs largely from each other for Poiseuille flows. This enigma has not been clarified so far owing to the difficult...

We study a large-scale instability in a sheared nonhelical turbulence that causes generation of large-scale vorticity. Three types of the background large-scale flows are considered, i.e., the Couette and Poiseuille flows in a small-scale homogeneous turbulence, and the "log-linear" velocity shear in an inhomogeneous turbulence. It is known that laminar plane Couette flow and antisymmetric mode...

Many flows at microscale and below are characterised by an inherent multiscale nature and accurate numerical modelling of the phenomena involved is the cornerstone for enhancing the applicability of micro and nanofluidics in the industrial environment. This paper presents a hybrid molecular-continuum strategy named as point wise coupling for studying complex microand nanoscale flows. In this st...

Abstract An in-house Direct Simulation Monte Carlo (DSMC) code has been developed using an object-oriented interface for the purpose of eventually modelling gas and plasma microflows in micromechanical systems, by coupling it with existing Particle-In-Cell (PIC) solver. The is validated canonical flow problems such as micro-Couette micro-Poiseuille flows. Since emphasis on supersonic highly com...

We derive a class of equations describing low Reynolds number steady flows incompressible and viscous fluids in networks made straight channels, with several sources sinks adaptive conductivities. A graph represents the network, fluxes at control flow. The conductivities describe transverse channel elasticities, mirroring network structures found physics biology. Minimising dissipated energy pe...

A continuum mechanical model is presented to analyze the negative electrorheological responses of a particle-liquid mixture with the suspended micro-particles undergoing Quincke rotation for both Couette and Poiseuille flow geometries by combining particle electromechanics and continuum antisymmetric/couple stress analyses in the zero spin viscosity limit. We propose a phenomenological polariza...