at present study the flow and heat transfer of non-newtonian nanofluid, aqueous solution of carboxymethyl cellulose-aluminum oxide with different volume fractions of nano particles in a two dimensional microtube is simulated for the first time. slip velocity and temperature jump boundary conditions are also considered along the microtube walls. the achieved results accuracy is investigated by c...

A simple molecular model is studied to explain wall slip in a polymer melt. We consider a tube model for tethered chains in which the most important relaxation mechanisms: convective constraint release and chain stretching (retraction), are incorporated. Furthermore, we take the interactions between tethered chains and bulk flow self-consistently into account. Numerical simulations show that ou...

Existence of a weak solution for the problem of dynamic frictional contact between a viscoelastic body and a rigid foundation is established. Contact is modelled with the Signorini condition. Friction is described by a slip rate dependent friction coefficient and a nonlocal and regularized contact stress. The existence in the case of a friction coefficient that is a graph, which describes the j...

Polymer – surface interactions strongly influence many important industrial and rheological flows. In particular, polymer melts and solutions slip against the surface; this has long been associated with sharkskin and spurt in extrusion, and recent experimental observations suggest that slip also plays a role in the formation of enhanced concentration fluctuations in entangled polymer solutions....

Microscale fluid dynamics has received intensive interest due to the emergence of MicroElectro-Mechanical Systems (MEMS) technology. When the mean free path of the gas is comparable to the channel’s characteristic dimension, the continuum assumption is no longer valid and a velocity slip may occur at the duct walls. Non-circular cross sections are common channel shapes that can be produced by m...

Molecular dynamics simulations are carried out to investigate the dynamic behavior of the slip length in thin polymer films confined between atomically smooth thermal surfaces. For weak wall-fluid interactions, the shear rate dependence of the slip length acquires a distinct local minimum followed by a rapid growth at higher shear rates. With increasing fluid density, the position of the local ...

Direct yaw moment control is an effective means to enhance vehicle stability and handling. The majority of the latest direct yaw moment control works employ sliding mode control to generate the target yaw moment. This paper proposes a new sliding mode-based direct yaw moment control method for simultaneous tracking of desired yaw rate and vehicle side-slip for electric and hybrid vehicles equip...

We estimate the rate of aftershocks triggered by a heterogeneous stress change, using the rate-and-state model of Dieterich [1994]. We show than an exponential stress distribution P (τ) ∼ exp(−τ/τ0) gives an Omori law decay of aftershocks with time ∼ 1/t, with an exponent p = 1−Aσn/τ0, where A is a parameter of the rate-and-state friction law, and σn the normal stress. Omori exponent p thus dec...