In this paper, we simulate steady inviscid flows over a cylinder using potential and stream functions, including entropy and vorticity corrections for incompressible, subsonic, transonic and supersonic flows. The present hierarchical formulation is equivalent to Euler equations satisfying conservation of mass, momentum and energy. Standard numerical schemes and iterative algorithms are used for...

The lubricating oils in each mechanical device are affected by shear forces. Polymers in lubricating oils engine, in particular, undergo many changes because of the influence of the applied forces. Awareness of these changes can help us to design optimal formulations. In this work, shear stability of four commercial was studied. Calculation of various parameters about viscosity in the enhancing...

Motivated by seismological problems, we have studied a fourth-order split scheme for the elastic wave equation. We split in the spatial directions and obtain locally one-dimensional systems to be solved. We have analyzed the new scheme and obtained results showing consistency and stability. We have used the split scheme to solve problems in two and three dimensions. We have also looked at the i...

Design of shear walls is a complex procedure, especially if the cross section of the shear wall is not regular in shape. Shear walls are usually treated like cantilevers fixed at the foundation level. Normally, lift wells are designed as shear walls. The design of shear walls takes horizontal forces into account by shear and bending. Design for shear in the walls can be managed by computing the...

nowdays, production of high quality engine oils is one of the worries of our country’s engine oil industry. in this study, the behavior of four commercial polymers used in nation motor oil industry in obtaining the best viscosity index improver was investigated. in this regard, viscometric behavior, shear stability and polymers’ performance for engine cranking were compared at low temperature. ...

the effect of weak shear thickening and shear thinning on the stability of the taylor-couette flow is explored for a carreau-bird fluid in the narrow-gap limit. the galerkin projection method is used to derive a low-order dynamical system from the conservation of mass and momentum equations. in comparison with the newtonian system, the present equations include additional nonlinear coupling in ...

The aim of this paper is to study the L1-stability of periodic stationary solutions of scalar convection-diffusion equations. We obtain dispersion in L2 for all space dimensions using Kružkov type entropy. And when the space dimension is one, we estimate the number of sign changes of a solution to obtain L1-stability. Keyword : L-stability, periodic stationary solutions, entropy, dispersion ine...

The shear strength of cohesionless granular materials is generally attributed to the compactness or anisotropy of their microstructure. An open issue is how such compact or anisotropic microstructures, and thus the shear strength, depend on the particle properties. We first recall the role of fabric and force anisotropies with respect to the critical-state shear stress. Then, a model of accessi...

The task of keyword extraction aims at capturing expressions (or entities) that best represent the main topics of a document. Given the rapid adoption of these online semantic annotators and their contribution to the growth of the Semantic Web, one important task is to assess their quality. This article presents an evaluation of the quality and stability of semantic annotators on domain-specifi...