Réponse a un signal thermique sinusoïdal dans le cas d'un écoulement laminaire a plan directeur

A theoretical and numerical study of laminar forced convection in both parallel-plate channels, subjected to a sinusoidally varying inlet temperature, is presented. The plate's thermal response is coupled to the fluid via the congugation conditions at the interface (boundary condition of the fourth kind). A thermal diffusion in the plate and a boundary condition that accounts for external convection are considered. The temperature amplitude and phase lag are determined as a function of four parameters. The results are compared at the classical hypothesis of isothermal plates used by several authors. Exactness of the numerical scheme solutions are established by comparison with exact solutions for slug flows.     

Modélisation d'un panache d'émetteur de chaleur pour le logiciel de simulation énergétique des bâtiments SPARK

Plume's convector modeling for object-oriented thermal building simulation software SPARK. In this paper, a zonal model used to predict air movement and temperature distribution in a room is presented. This model is based on a rough partitioning of the room: it is an intermediate approach between one-node models (that consider a homogeneous temperature in each room) and CFD models. Flow rates are calculated in respect to the pressure distribution in low velocity domains and specific laws describe plumes and jets. The airflow model is coupled with a building envelope model. They are implemented in an object-oriented environment called SPARK. The modularity of SPARK allows the creation of very flexible tools, and its strict syntax permits having the simulations automatically generated.     

Un modèle simple de la pénétration couplée de chaleur et de matière dans l'absorption gaz-liquide en film ruisselant laminaire

In this paper we present a simple model based on the coupled penetration of heat and mass fronts for the study of the absorption kinetics of vapor in a concentrated salt solution falling in laminar flow down an adiabatic wall. Though this model is very simple, it permits a concrete and intuitive comprehension of the numerical integration of differential equations. The forecasts of this model, in the case of the absorption of water vapor in the lithium bromide solution, are presented and compared to the results of the numerical solution.     

Séchage superficiel d'un matériau poreux humide par convection forcée d'air chaud: couplage entre les équations de transfert dans le matériau et celles de la couche limite

The authors considered drying of a thick slab of humid porous material immersed in a laminar steady flow of hot air parallel to its surface. They wrote the boundary layer equations in air (continuity, momentum, energy and mass), those describing humidity and heat transfer in the porous medium deduced from Luikov's theory. Then, they coupled them at the air-product interface by expressing the continuity of the thermal and mass fluxes taking into account the evaporation. They solved numerically the resulting system of differential equations using an implicit finite-difference method. They determined the instantaneous evaluation of the spatial distributions of heat and humidity, the local values of the Nusselt and Sherwood numbers. They also studied the influences of principal parameters of the system.