Heat Transfer 2

Michel Ledoux was Professor and Vice-President at the University of Rouen, France. He was also Director of the UMR CNRS CORIA, then Regional Delegate for Research and Technology in Upper Normandy, France. Specializing in fluid mechanics and transfers, he has worked in the fields of reactive boundary layers and spraying. Currently retired, he is an adviser to the Conservatoire National des Arts et Métiers in Normandy, collaborating with the Institute of Industrial Engineering Techniques (ITII) in Vernon, France. Abdelkhalak El Hami is Full Professor of Universities at INSA-RouenNormandie, France. He is the author/co-author of several books and is responsible for the Chair of mechanics at the Conservatoire National des Arts et Métiers in Normandy, as well as for several European pedagogical projects. He is a specialist in problems of optimization and reliability in multi-physical systems.

• Preface ixIntroduction xiiiChapter 1. General Remarks 11.1. Introduction 11.2. Propagation of a sinusoidal electromagnetic wave 11.2.1. Frequencies and wavelengths 11.2.2. Radiation spectrum 41.3. The concept of photometry 61.3.1. Geometric parameters 61.3.2. Radiance 91.3.3. Bouguer–Lambert law 121.3.4. Intensity 131.3.5. Lambert’s law – a surface’s emissivity 14Chapter 2. Calculating Luminances 172.1. Introduction 172.2. The black body: concept, luminance, Planck’s law and approximations 182.2.1. Paradoxically, the black body is defined with reference to its absorption 182.2.2. Black body luminance 192.2.3. Emittance from the black body 222.2.4. Approximations of the luminance of the black body 232.2.5. Writing the luminance in terms of frequency 252.3. Stefan–Boltzmann law 272.3.1. Establishing the law 272.3.2. A direct application 292.4. Wien’s laws 322.4.1. Wien’s displacement law 322.4.2. Wien’s second law 342.4.3. Greenhouse effect 352.5. Fraction of the total emittance of a black body radiated in a spectral band 382.5.1. An important tool: G0−λT functions 382.5.2. An application 422.6. Emissivity of any body: a general case of a non-black body 432.6.1. Definition of monochromatic emissivity 432.6.2. Definition of global emissivity: a tricky concept 452.6.3. Emissivity of a gray body: a particular case 452.7. Simple applications 48Chapter 3. Emission and Absorption 533.1. Introduction 533.2. Absorption, reflection, transmission 533.3. Kirchhoff’s law 563.4. Recap on the global absorption coefficient 573.4.1. General case 573.4.2. Case of the gray body 583.5. General case: multiple transfers 593.6. Absorption: the Beer–Lambert law 613.6.1. Radiation transfer 613.6.2. Beer’s law 62Chapter 4. Radiation Exchanges Between Surfaces 654.1. Introduction 654.2. Classification 654.3. The case of total influence 664.3.1. The case of two parallel plates. Lambert’s law 664.3.2. Total influence between two black body surfaces, of temperatures Tw and Ta 684.3.3. Total influence between two surfaces 684.3.4. Total influence between two surfaces 694.3.5. Wall in total influence in an enclosure 714.3.6. Important note on the “thermal balance” 724.3.7. A practical approximation 724.3.8. Complex system of radiant finished surfaces: geometric form factor 754.3.9. Application 79Chapter 5. Analytic Applications 895.1. Introduction 895.2. Radiators, convectors and radiating fins 895.3. Radiation and oven 1145.4. Radiation and metrology 1235.4.1. Measuring a thermal conductibility 1375.5. General problems 148Chapter 6. Modeling and Simulations under ANSYS 1696.1. Conduction, convection and radiation 1696.2. Conduction and convection using ANSYS software 1726.2.1. Representation of the temperature field 1746.3. Radiation using ANSYS software 1756.4. Examples of modeling and analysis with ANSYS 1776.4.1. Simple thermal conduction 1776.4.2. Mixing conduction/convection/isolation 1806.4.3. Transient thermal conduction 1826.4.4. Study of thermal transfers from a brick wall and a cement wall (application to an oven) 1866.4.5. Study of stationary thermal conduction in a reservoir intersected by a tube 1916.4.6. Stationary thermal conduction on a cylinder 1966.4.7. Cooling of a puck in transitory thermal 1996.4.8. Study of a heat exchanger 2026.5. Study of a thermal exchanger on ANSYS 2046.5.1. Effectiveness of the PCM 2046.5.2. Parameterizing the analysis 2046.5.3. Thermal exchanger without an PCM 2076.5.4. Thermal exchanger with hydrated salt 2076.5.5. Thermal exchanger with paraffin 2106.5.6. Influence of heat flux 2126.5.7. Comparing PCM 2136.6. Conclusion 214Appendix. G0−λT Function Table 217References 223Index 225