Imposed pressure driven flow in peristalsis

Peristaltic transport phenomena are of great significance in biological sciences. The physiological transport of fluid takes place under the action of peristalsis generated as a pressure gradient. The peristaltic waves generate a pressure gradient which is responsible for the fluid flow in the forward direction. The further properties of this phenomena can be seen if an imposed pressure gradient is applied in addition to the one appearing due to peristaltic waves. This situation has not been discussed in the literature that needs further attention. The effects of the wavy boundaries and imposed pressure on the velocity of the flow field are analyzed. Here we impose a question: what happens if an imposed pressure gradient is also applied? This question of physical importance has not been addressed; and thus, remains the topic of this study. In previous papers of peristaltic motion, the flow generated by peristaltic waves only has been examined while in this study we will discuss the contribution of imposed pressure gradient on velocity field. The analytical results for the velocity field are obtained using the boundary perturbation method. The study shows that the impact of the wavy boundaries on the flow increases with the increase in corrugation parameter and imposed pressure.

Radiation of waves by a thin cap submerged in ice-covered ocean

Summary The present article is concerned with the radiation of flexural gravity waves due to a thin cap submerged in the ice-covered ocean. The problem is reduced to a system of hypersingular integral equations using the boundary perturbation method. The first-order approximation has only been considered. The effects of the rigidity of the ice sheet and depth of submergence on the added mass and damping coefficient have been analysed. Two types of caps (for example, concave upwards and concave downwards) have been considered for the numerical results. The effect of the concavity on added mass and damping coefficient has also been studied. The present study should be helpful to understand the nature of waves generated by a heaving submerged body in an ice-covered ocean.

Optimal Form for Compliance of Membrane Boundary Shift in Nonlinear Case

In this work, we search the existence shifting compliance optimal form of some boundary membrane, which is not elastic and not isotropic, generating nonlinear PDE. An optimal form of the elastic membrane described by the p-Laplacian is investigated. The boundary perturbation method due to Hadamard is applied in Sobolev spaces.

Nearly frictionless states of ultra-high temperature amorphous matter

The almost frictionless transport of very high-temperature amorphous matter that resembles colored glass condensate (possibly having much of its origin in the RHIC heavy ion collisions) in a confined annular tube with transverse corrugations is investigated using the verified transition-rate model and boundary perturbation method. We found that for certain activation volume and energy there exist possible frictionless states that might be associated with perfect fluid formation during the early expansion stage in RHIC Au+Au collisions. We also address the possible similar scenario in LHC Pb+Pb collisions considering possible perfect fluid formation in ultra-high temperature transport of amorphous matter.

FLOW BEHAVIOR OF AN EYRING-FLUID IN NANODOMAIN: EFFECT OF SMALL WAVY-ROUGHNESS

The steady velocities and volume flow rates (up to the second order) of an Eyring-fluids along the cross-section of an (approximated) wavy-rough nanotube are obtained analytically by using the verified fluid model and boundary perturbation method. Our results show that the wavy-roughness could tune the flow rate especially for larger forcing due to the larger surface-to-volume ratio and slip-velocity effect. The effects of wave number and slip length are also addressed.