STUDY OF THE INFLUENCE OF THE DIAMETER OF MODIFIED TOOLS WITH INTERNAL COOLING CHANNELS UNDER DIFFERENT THERMAL FLOWS

In this work, the effect on heat generation at the chip-machine tool interface was studied by varying the diameter of internal grooves of a tool for the turning process. This tool is modified with internal channels that circulate water as a coolant through a closed system. As an output parameter, the maximum cutting temperature at the chip-tool interface was studied. The input parameters were the thermal flux present at the chip-tool interface and the diameter of the internal channels present in the cutting tool. All the analysis of variation of the internal channels of the tools and also of the thermal flow exerted on the chip-tool interface were carried out using the finite element method by the Ansys® Workbench 19.2 software. The main one was that the variation in the diameter of the tool's internal grooves does not expressly impact the machining specifications.

Thermal Flows

Flows of thermal origin and heat transfer problems are central in a variety of disciplines and industrial applications [...]

Multiscale Modeling of Convection and Pollutant Transport Associated with Volcanic Eruption and Lava Flow: Application to the April 2007 Eruption of the Piton de la Fournaise (Reunion Island)

Volcanic eruptions can cause damage to land and people living nearby, generate high concentrations of toxic gases, and also create large plumes that limit observations and the performance of forecasting models that rely on these observations. This study investigates the use of micro- to meso-scale simulation to represent and predict the convection, transport, and deposit of volcanic pollutants. The case under study is the 2007 eruption of the Piton de la Fournaise, simulated using a high-resolution, coupled lava/atmospheric approach (derived from wildfire/atmosphere coupled code) to account for the strong, localized heat and gaseous fluxes occurring near the vent, over the lava flow, and at the lava–sea interface. Higher resolution requires fluxes over the lava flow to be explicitly simulated to account for the induced convection over the flow, local mixing, and dilution. Comparisons with air quality values at local stations show that the simulation is in good agreement with observations in terms of sulfur concentration and dynamics, and performs better than lower resolution simulation with parameterized surface fluxes. In particular, the explicit representation of the thermal flows associated with lava allows the associated thermal breezes to be represented. This local modification of the wind flow strongly impacts the organization of the volcanic convection (injection height) and the regional transport of the sulfur dioxide emitted at the vent. These results show that explicitly solving volcanic activity/atmosphere complex interactions provides realistic forecasts of induced pollution.

Thermal flows in fractured porous media

We consider the thermal flow problem occuring in a fractured porous medium. The incompressible filtration flow in the porous matrix and the viscous flow in the fractures obey the Boussinesq approximation of Darcy-Forchheimer law and respectively, the Stokes system. They are coupled by the Saffman's variant of the Beavers-Joseph condition. Existence and uniqueness properties are presented. The use of the energy norm in describing the Darcy-Forchheimer law proves to be appropriate. In the ε-periodic framework, we find the two-scale homogenized system which governs their asymptotic behaviours when ε tends to 0 and the Forchheimer effect vanishes. Mainly is a model of two coupled thermal flows, neither of them being incompressible.