Transferts ThermiquesSciences pour l'Ingénieur (ERE)

Know: • The laws of thermal transfer by: radiation, conduction and convection Master: • The basic rules of the thermal and aerothermal of the building in order to: o Be able to model the thermal exchange of a building o To define the thermal optimization axes of the building following an assessment of the thermal losses of an envelope and/or ventilation circuit o To dimension the system and its sub-assemblies of air conditioning and production or management of sanitary hot water

Heat transfer - Thermal conduction Heat Conduction Introduction This teaching presents the basic concepts necessary for approaches to thermal transfer phenomena. It helps to deal with classical situations and allows students to understand frequent situations where the thermal behaviour of the material must be taken into account Thermal conduction predicts the heat flow transferred into a system or process Objectives • Mastering knowledge of heat transfer by conduction in the fields of energy • Know the basic concepts: temperature, heat flux, Fourier's behavior law, heat source heating, temperature gradient, isotherms, isoflux, thermal resistance • Formulate in mathematical form the problem of conduction, choose the conditions at the limits • Analytically or numerically solve (various calculation codes) a conduction problem, interpret results to verify or dimension a system Elements to be incorporated into the content of the lessons Fourier's law, thermal gradient, thermal conductivity Equation of conduction • The first principle of thermodynamics and heat equation • Limit conditions and initial condition Permanent thermal regime • Heat transmission through a homogeneous or compound wall • Concept of wall, surface, contact thermal resistance • Two-dimensional permanent problems in limited medium: method of variable separation • Applications • Mathematical formulation of conduction problems, critical insulation thickness • Two-dimensional continuous driving • Heat transfer through a single or multilayer wall in continuous operation • Thermal conductivity measurement of solids using the thermal barrier method • Measurement of thermal diffusion and flux 2

Detailed summary • Heat conduction in a medium has a dimension. Fourier's law. The heat flow vector. Thermal conductivity: typical values for insulation and conductors • Equation of heat in 1 D medium. The thermal diffusion coefficient. Resolving the wall problem in the stationary case • 3D heat equation. Case without heat source. Case with heat source (or well) • Examples of heat equation solutions. Temperature profile in a cylindrical electric wire driven by a constant current and heated by Joule effect. Temperature profile in a spherical medium with source term (radioactive material ball). Solution of the heat equation in the case of a sinusoidal thermal attack: heat waves and their attenuation according to the distance travelled • Discretization of the heat equation Binder-Schmidt graphical resolution method. Application to the calculation of temperature change as a function of time in the furnace wall • Thermal resistance. Convection-type boundary conditions • Application: calculation of the thermal strength of a cylindrical pipe. Effect of heat repellent and identification of the critical radius of heat repellent • Directed work: the wall with source term; Pomerantsev criterion. Treatment of an infinite cooling wing. Presentation of the finished length fin

Table Control (Duration 1h30)

Heat transmission (Tome 1, 2) - A. B. De Vriendt; Gäetan Morin Publisher, 1982 Initiation of thermal transfer - J. F. Sacadura; Lavoisier (Tec & Doc), 1977 Fundamentals of Heat and Mass Transfer - F. P. Incropera and D. P.Dewitt; J. Wiley edition, 4th edition, 1988 Heat Transfer - J. P. Holman; McGraw Hill, S. I. Metric Edition, 1989 Heat Transfer, a Basic Approach Mr. N. Ozisik; McGraw Hill, 1985 Heat Conduction Mr. N. Ozisik; J. Wiley edition, 1980 Boundary Value problems of Heat Conduction Mr. N. Ozisik; Dover Publication, 1976 Conduction Heat Transfer - V. P. Arpaci; Addison Wesley Edition, 1956 Analysis of heat and Mass transfer - E. R. G. Eckert and R. M. Drak; McGraw Hill, 1959 Conduction in Solids - Carslaw and Jaegger; Oxford Publication, 1959.