1 Heat and Mass Transfer Prof. S. P. Sukhatme Department of Mechanical Engineering Indian Institute of Technology, Bombay Lecture No. 01 Namaste. My name is S P Sukhatme and along with my colleague professor U N Goitonade, I will be giving you a series of lectures on the subject of heat and mass transfer. We are from the department of mechanical engineering at the IIT Bombay. Now the subject matter which we will be covering under these lectures is the syllabus as is prescribed for the subject ‘heat and mass transfer’ in most universities in India and we will be doing this through about thirty odd lectures. We are from the department of mechanical engineering as I said. So, the matter that we will cover will be primarily from the point of view of mechanical engineering students. However, heat and mass transfer is an important subject also in the chemical engineering curriculum, in the aeronautical engineering curriculum and also taught, parts of it are also taught in other disciplines. So, although we will be covering the subject from the point of view of what is the syllabus in mechanical, what we have to say would, I think, be of interest also to students from other disciplines. We will proceed something like this. I will give you an outline of the lectures which we are going to give. First of all, we will have an introduction to the subject covering a few lectures to cover the laws - the basic laws - that govern the subject.
2 (Refer Slide Time: 02:32) Then, we will move on to the topic of heat conduction in solids, then thermal radiation, then the mode of heat transfer by convection and in this we will talk first of forced convection, then natural convection, then we will go on to change of phase. Change of phase means: either during the heat transfer process a liquid gets converted into vapor because it receives heat - latent heat - which converts it from liquid to vapor or heat is taken out of it and therefore it condenses and from the vapor state it becomes liquid. Now, during this heat transfer process what is the rate at which heat transfer occurs forms the subject matter of the topic condensation and boiling. Then we move on to the topic of heat exchangers. Heat exchangers are devices which are widely used for a variety of purposes in many applications to transfer heat from one fluid to another - one fluid at a higher temperature, one fluid at a lower temperature. And we will talk about the thermal design and the working of such heat exchangers and then finally we will go to the topic of mass transfer and introduce the elements of mass transfer. Now, you may ask me the question why is mass transfer taught alongside heat transfer when really we are covering heat transfer through most of these lectures. And the answer is something like this. The process of mass transfer has many similarities with the process of heat transfer. Heat transfer occurs when there is a temperature difference. Mass