The book describes the concept of heat transfer in different realistic situations. It contains 15 chapters which are completed with 4 addenda.
In the short introduction, the author describes the concept of heat transfer and the three modes conduction, convection and radiation. He presents the many possible branches of engineering and of technology where heat transfer is present.
The author starts in the first chapter with the introduction of the heat flux written as \(q=-\lambda \frac{dt}{dn}\), where \(\lambda \) is the thermal conductivity and \(\frac{dt}{dn}\) is the temperature gradient in the direction of the normal \(n\) to the surface. In the case of an isotropic body, the heat flux through a surface element \(dA\) may be written as \(q= \frac{d\dot {Q}}{dA}\), where \(\dot {Q}\) is the heat transfer rate. Then, the author writes the heat flux in any direction \(s\) as \(q_{s}= \frac{d\dot {Q}}{dA}\cos \delta =-\lambda \frac{dt}{dn}\cos \delta \), where \(\delta \) is the angle between the direction \(s\) and the normal \(n\). This leads to the introduction of the heat flux vector \(\overrightarrow{q}\) using the three components \(q_{x}\), \(q_{y}\) and \(q_{z}\). Writing the first law of thermodynamics, the author derives the net heat flow out of the volume element \(dxdydz\) for an isotropic body at rest \(\Delta \dot {Q} _{x}=-\frac{\partial }{\partial x}(\lambda \frac{dt}{dx})dxdydz\) (and similar expressions for the other components). This leads to the heat equation for an isotropic body, this heat equation being then written in cylindrical or spherical coordinates. The chapter ends with a short description of the boundary conditions which may be associated to this heat equation.
In Chapter 2, the author focuses on the dependence of the thermal conductivity on physical quantities and for different media (gas, solid or liquid). A table gathers the values of the thermal conductivity for the main materials.
Chapter 3 is devoted to the study of the steady heat conduction process. The author starts with a plane wall or with a multilayered plane wall. He then considers circular or spherical tubes or layers, and many other realistic situations. In each case, he solves this steady heat equation.
In Chapter 4, the solution of the unsteady heat equation is given in some particular cases. The author mainly uses the method of separation of variables.
In the short Chapter 5, the author considers the heat convection for a multiphase body with moving interphase. He describes here the melting and sublimation processes.
Chapter 6 is devoted to the description of the convection process. Considering solid bodies, the author writes the mass conservation equation, the equation of motion (Navier-Stokes’ equation) and the energy equation (using the first law of thermodynamics). The chapter ends with the description of some particular cases and with the introduction of the notion of similarity.
In Chapter 7, the author builds some similarity solutions for the boundary layer equation and for 2D, steady and incompressible flows with negligible body forces. He introduces the stream function and ends with a coupled system of two odes which describes the evolution of the stream function and of the temperature distribution. The resolution of this system is drawn using the Runge-Kutta method.
In Chapters 8 and 9, the author deals with forced convection for laminar or turbulent flows. The author justifies the study of laminar flows considering heat exchangers with narrow channels. Chapter 8 describes the conditions and the properties of laminar flows. Some particular examples are studied in detail and the chapter also describes the transition to turbulent flows which are further described in Chapter 9. The author starts here with the Navier-Stokes equations and the equation for the temperature field in order to describe turbulent flows. He then studies the cases of pipes, tubes and flows between flat plates. The role of different parameters is emphasized for the characterization of turbulent flows.
Natural convection is presented in Chapter 10, which is characterized through the property \(\frac{\mathrm{Gr}}{\mathrm{Re}}\gg 1\), where \(\mathrm{Gr}\) (respectively, \(\mathrm{Re}\)) denotes the Grashof (respectively, Reynolds) number. The case of vertical surfaces is first considered with a laminar boundary layer. The author writes the corresponding equations and boundary conditions. He solves this problem partly considering the stream function. The cases of horizontal circular cylinders and of enclosures are finally considered.
The forced convection is analyzed in Chapter 11 for bodies which are immersed in a flow. The author intends, for example, to model heat exchangers. The author considers cylinders, tube bundles or spheres, and describes the convective heat transfer from such bodies. He essentially gives the expression of some characteristic numbers which can be associated to the convective heat transfer in such situations.
In Chapter 12, the author moves to the third mode of heat transfer that is thermal radiation. He first describes the physical mechanism introducing discrete quanta. He introduces the reflectivity \(\rho \), the absorptivity \( \alpha \) and the transmissivity \(\tau \), which are linked through \(\rho +\alpha +\tau =1\). This leads to the notions of opaque surface (\(\tau =0\)) and of black body (\(\rho =0\)). The Stefan-Bolzmann law is introduced which describes the radiation from a black body. The chapter ends with examples of radiations between different materials.
The condensation process is explained in Chapter 13. The author first considers a film condensation along a vertical surface for a laminar flow. He writes the mass conservation equation, the momentum equation and the temperature field equation for the liquid and vapour layer. He introduces the Nusselt simplifying assumptions and the corresponding boundary conditions. The case of a turbulent flow in the condensate layer is then considered. Next, the author considers other, different situations where a film condensation occurs.
Chapter 14 is devoted to the description of the boiling and evaporation processes. The chapter starts with the presentation of some experimental results concerning the heating of saturated water, leading to typical boiling curve. The author decomposes the mechanism of the boiling process in different zones along this boiling curve: natural convection, nucleate boiling (with single bubbles and vapour jets), maximum heat flux, transition regime and film boiling. Each zone is then analyzed and characterized with some appropriate characteristic numbers. The chapter ends with the study of two-phase flows (gas-liquid) and the description of the heat flux which occur within this context.
The final Chapter 15 deals with the study of heat exchangers. The author starts with the description of some typical heat exchangers which are used in different contexts. He then introduces two methods which quantify the properties of such exchangers.
The book ends with addenda which gather some mathematical tools such as the Laplace transform, or some computations on the balance equations. The final addendum gathers some exercises on the concepts developed throughout the book, the author ending this addendum with some hints on these exercises.
Many figures illustrate the different chapters which make the book easy to read. The author indeed presents both the physical concepts and some mathematical computations, both being illustrated with appropriate figures.