Convection, Conduction and Radiation Essay Example | Topics and Well Written Essays - 1500 words

Convection, Conduction and Radiation - Essay Example The energy transferred from one system to another is called the internal energy. Internal energy is, although not in all cases, is proportional to temperature. Essentially, the transfer of energy or heat starts from the system with the higher temperature to the system with the lower temperature. The higher the internal energy of the system, the higher is the temperature of the system. However, there are cases when there are no changes on the temperature of the system even though there was an increment on the internal energy of that system. Such case will be explained later as part of the examples of conduction. There are several ways on how to transfer energy or heat: thermal convection, thermal conduction and thermal radiation or simply called convection, conduction and radiation. These three modes of transfer of energy have different operations going on. This particular study aims to explain heat transfer via the three methods aforementioned. Keywords: conduction, convection, radia tion, internal energy, heat, system HEAT TRANSFERS: CONVECTION, CONDUCTION, AND RADIATION 3 Thermal Convection Thermal convection, also known as convection, is a transfer of heat from one object to another wherein the heat travels in motion through liquids. In Physics, fluids include liquid substances, gases, and some plastic solids. When the temperature of a liquid rises, the liquid becomes lighter or less dense; nevertheless, if the temperature of the liquid decreases, it becomes denser and it relatively falls down. In thermal convection, what happens is that when there is a massive motion by the liquids like gases or liquid substances, it tends to create a circular motion since a solid body, when heated, transfers the energy to the liquid. Convection takes place when the liquid that was heated becomes lighter and therefore rises. When it reaches the top of the circulation, the temperature of the liquid decreases, hence, making it denser which causes it to fall down. The cycle cre ates convection current. Further, free convection takes place when the movements of the fluids are caused to move by the buoyant forces as a result of varying densities brought about by the rapid changed in the temperature. Forced convection, on the other hand, takes place when the fluid gets in contact with the surface of the solid system using outside or external means. There are several examples that will help us clearly understand the principles behind thermal convection. If you happen to observe when you boil pasta or beans, the moment the water (liquid) reaches its boiling point, the beans or the pasta moves up and down and from side to side or it triggers the pasta or the beans to move in random directions. The explanation of this HEAT TRANSFERS: CONVECTION, CONDUCTION, AND RADIATION 4 particular scenario as what have been explained earlier is that, the moment the temperature of the liquid increases, it becomes less dense or lighter causing it to rise above the surface and wh en it reaches the top and it cools down, which means there is a relative decrease on the temperature, it becomes denser and therefore falls down which creates a cycle. The changes on the temperature and the density of the liquid are principal factors causing the rising and falling movement of the pasta and the beans. The portion where