Kossi Atchonouglo

Identification of the Dynamic Coefficients of Hybrid Bearings

Within the linear region, the oil-film force increment of journal bearing is a fourdegree- of-freedom linear system. This paper presents an experimental method to identify hybrid bearing coefficients. Under various testing conditions described, experimental data are required on a complex test rig. An inverse technique based on least square method in time domain is developped for the coefficients identification. It results from the experimental data exploitation that the linear stiffness and damping coefficients are sensitive to the pressure feed, but the mass coefficients are insensitive.

Simulation of Thermo Mechanical Behavior of Structures by the Numerical Resolution of Direct Problem

The aim of our study is to develop an approach to both experimental and numerical modeling to the thermal behavior of a material by identifying these thermal parameters. The theoretical part is based on the finite element method which is a starting point to solve a two-dimensional inverse heat. The experimental measurements are performed by infrared thermography. All these experimental and numerical techniques give this method properties valued in the industrial world as the non-intrusive measurements and real-time calculations. For this, we have supported a system of equations and the temperature field, so before starting the inverse problem, we addressed the direct problem by finite element method that has been compared to measures experimental infrared thermography well to check the validity of equations, so it’s the purpose of this work.

Investigation on the combustion of volatile organic compounds for a cleaner planet

The incineration of municipal wastes involves the generation of volatile organic compounds which contribute to climate change. The present study attempted to optimize volatile organic compounds combustion during municipal solid wastes incineration. A detailed numerical computation has been performed to investigate the turbulent combustion of volatile organic compounds considering radiative heat transfer. Mass, momentum, heat transfer and concentrations of chemical species are numerically studied by solving the respective governing equations using the CFD code “Fluent”, which uses the finite volume method. The standard k-epsilon model has been used to simulate the turbulent flow. The turbulence-chemistry interaction is depicted by Eddy-Dissipation model. Discrete ordinate method is used for the modeling of the radiative heat transfer. The effects of inclination angle of the incinerator, walls thickness and walls emissivity on flow field, temperature and concentration of chemical species distributions and combustion effectiveness are investigated. The results showed that the inclination angle of the incinerator is effective on the flow structure, temperature and concentration of chemical species distributions. The efficiency of the combustion of organic compounds decreases with the increase of the inclination angle and Reynolds number. The variation of the walls emissivity modifies the combustion process in the incinerator. The thermo destruction efficiency depends on the inlet and outlet ports position.

Identification of Thermal Parameters by Treating the Inverse Problem

aim of this work is to identify the tensor of thermal conductivity and volumetric heat of an anisotropic material with conductivity tensor diagonal, the heat conduction follows the linear Fourier law. The temperature field in the plate is obtained by solving the analytical heat equation. The solution of the direct problem is simulated by applying the Finite Element Method 2D. The inverse problem is solved by returning the intermediate step of the MEF. An optimization method based on conjugate gradient algorithm has enabled us to develop an identification of thermophysical parameters procedure.