Research status of laser cladding on titanium and its alloys: A review

Effects of hydrogen and initial pressure on flame characteristics and explosion pressure of methane/hydrogen fuels

A review of studies on bricks using alternative materials and approaches

A three-dimensional transient numerical model was developed to study the temperature field and molten pool shape during continuous laser keyhole welding. The volume-of-fluid (VOF) method was employed to track free surfaces. Melting and evaporation enthalpy, recoil pressure, surface tension, and energy loss due to evaporating materials were considered in this model. The enthalpy-porosity technique was employed to account for the latent heat during melting and solidification. Temperature fields and weld pool shape were calculated using FLUENT software. The calculated weld dimensions agreed reasonable well with the experimental results. The effectiveness of the developed computational procedure had been confirmed.

Numerical simulation of transient temperature field during laser keyhole welding of 304 stainless steel sheet

CFD analysis of flow forces and energy loss characteristics in a flapper–nozzle pilot valve with different null clearances

A pulse laser (Nd:YAG) interaction with an AZ91 magnesium alloy has been experimentally and numerically studied. A two-dimensional (2D) axisymmetric model of a molten pool created by a laser heat source has been developed. The elaborated model solves the coupled equations of a laminar fluid flow and heat transfer to demonstrate the flow behavior in the pool. This model takes into account the coupled effects of buoyancy and Marangoni forces, the thermophysic variation properties with temperature, and the radiation and convection heat losses. Concerning numerical results, the molten temperature distribution, velocity field and molten shape were discussed. It was noted that the Marangoni flow significantly alters the characteristics of the thawing and solidifying processes, and makes the molten pool wider and shallower. On the other hand, the experimental results showed that the material thermal properties have significant effects on the transport phenomena which takes place in the molten pool, and consequently on the formation as well as the shape of the pool. Finally, a comparison between the numerical and experimental results exhibited a good agreement.

Numerical and experimental studies of molten pool formation during an interaction of a pulse laser (Nd:YAG) with a magnesium alloy

Reduction of the energy consumption of a tunnel kiln by optimization of the recovered air mass flow from the cooling zone to the firing zone

A numerical study of a turbulent axisymmetric jet emerging in a co-flowing stream

This paper deals with the numerical prediction of an axisymmetric turbulent jet discharged into a co-flowing stream. Two computational codes have been employed, in-house code using the standard k-ɛ model and commercial CFD software including the standard k-ɛ and the RSM model. The main object of our research is to investigate the recirculation phenomena induced by the change of the inlet and boundary conditions.We observed different recirculating regions (central and corner) induced by the inclusion of the nozzle thickness δe. The size and the strength of these recirculation bubbles are intensified by increasing δe. We also observed that the co-flowing jet emitted with a different velocity profile generates a wide central recirculation bubble and a small corner vortex. However, the formation of the recirculation bubble is destroyed by decreasing Froude number. Furthermore, the analysis of the size and strength of the recirculation bubbles is necessary in the case of the jet pump and the flame in c...

Wassim Kriaa

Papers

Numerical and experimental studies of molten pool formation during an interaction of a pulse laser (Nd:YAG) with a magnesium alloy

Reduction of the energy consumption of a tunnel kiln by optimization of the recovered air mass flow from the cooling zone to the firing zone

A numerical study of a turbulent axisymmetric jet emerging in a co-flowing stream

Numerical Analysis of Recirculation Bubble Sizes of Turbulent Co-Flowing Jet

Swirl generator effect on a confined coaxial jet characteristics