Loading conditions and complex geometry have led the cylinder heads to become the most challenging parts of diesel engines. One of the most important durability problems in diesel engines is due to the cracks valves bridge area. The purpose of this study is a thermo-mechanical analysis of cylinder heads of diesel engines using a two-layer viscoplasticity model. The results of the thermo-mechani...

A quasi three-dimensional numerical model is developed to study vortex-induced vibration (VIV) of two tandem flexible circular cylinders. In this model, the whole cylinder is divided into many sections along its length. The hydrodynamics of each section are represented by the solution of the two-dimensional Navier-Stokes equations. The dynamic response of the flexible cylinder is predicted by t...

New direct spectral solvers for the 3D Helmholtz equation in a finite cylindrical region are presented. A purely variational (no collocation) formulation of the problem is adopted, based on Fourier series expansion of the angular dependence and Legendre polynomials for the axial dependence. A new Jacobi basis is proposed for the radial direction overcoming the main disadvantages of previously d...

The breakdown of finite element (FEM) computations for the flow of an Oldroyd-B fluid around a cylinder confined between parallel plates, at Weissenberg numbers Wi = O(1), is shown to arise due to a coil-stretch transition experienced by polymer molecules traveling along the centerline in the wake of the cylinder. With increasing Wi, the coil-stretch transition leads to an unbounded growth in t...

A numerical simulation of vortex-induced vibration of a 2-dimensional elastic circular cylinder with two degree of freedom under the uniform flow is calculated when Reynolds is 200. 2-dimensional incompressible Navier-Stokes equations are solved with the space-time finite element method, the equation of the cylinder motion is solved with the new explicit integral method and the mesh renew is ac...

Loading conditions and complex geometry have led the cylinder heads to become the most challenging parts of diesel engines. One of the most important durability problems in diesel engines is due to the cracks valves bridge area. The purpose of this study is a thermo-mechanical analysis of cylinder heads of diesel engines using a two-layer viscoelasticity model. The results of the thermo-mechani...

cylinder tumble flows of a single cylinder two-valve engine under motoring conditions with two pentroof pistons having different cavities at an engine speed of 1000 rev/min., during suction and compression strokes using particle image velocimetry (PIV). The two-dimensional velocity vector fields are analyzed on a vertical plane passing through the axis of the cylinder. To quantify the tumble fl...

The dispersion of pollutants, resulting from industrial chimneys, in the surrounding atmosphere made the interest in realizing emitting conditions appears. It also encourages the vertical dispersion of these pollutants. At a given wind velocity, the height of this dispersion is essentially a function of the thermal power and the flow rate at the chimney exit. To improve these qualities, we prop...