The Little Heat Engine:
Heat Transfer in Solids, Liquids and Gases
The question now is wherein the mistake consists and how it can be removed.
Max Planck, Philosophy of Physics, 1936.
While it is true that the field of thermodynamics can be complex,1-8 the basic ideas behind the study of heat (or energy) transfer remain simple. Let us begin this study with an ideal solid, S1, in an empty universe. S1 contains atoms arranged in a regular array called a "lattice" (see Figure 1). Bonding electrons may be present. The nuclei of each atom act as weights and the bonding electrons as springs in an oscillator model. Non-bonding electrons may also be present, however in an ideal solid these electrons are not involved in carrying current. By extension, S1 contains no electronic conduction bands. The non-bonding electrons may be involved in Van der Waals (or contact) interactions between atoms. Given these restraint, it is clear that S1 is a non-metal.
Ideal solids do not exist. However, graphite provides a close approximation of such an object. Graphite is a black, carbon-containing, solid material. Each carbon atom within graphite is bonded to 3 neighbors. Graphite is black because it very efficiently absorbs light which is incident upon its surface. In the 1800's, scientists studied objects made from graphite plates. Since the graphite plates were black, these objects became known as "blackbodies". By extension, we will therefore assume that S1, being an ideal solid, is also a perfect blackbody. That is to say, S1 can perfectly absorb any light incident on its surface.
Let us place our ideal solid, S1, in an imaginary box. The walls of this box have the property of not permitting any heat to be transferred from inside the box to the outside world and vice versa. When an imaginary partition has the property of not permitting the transfer of heat, mass, and light, we say that the partition is adiabatic. Since, S1 is alone inside the adiabatic box, no light can strike its surface (sources of light do not exist). Let us assume that S1 is in the lowest possible energy state. This is the rest energy, Erest. For our ideal solid, the rest energy is the sum of the relativistic energy, Erel, and the energy contained in the bonds of the solid, Ebond.
Most motor vehicles today use an Internal Combustion Engine (ICE) to give them power to drive down the road; ICEs are a form of a heat engine. Gasoline is burned to push a piston, which in return forces the car down the road. As the gas in the cylinder is ignited and expanded it forces the piston down the shaft. The force is carried through piston, which is connected to a crankshaft. The force moves through the transmission, down the driveshaft, and out the tires. The Otto Cycle is used to turn as much heat into the driving force as possible.
The amazing transformation the study of physics underwent in the two decades following the turn of the 20th century is a well-known story. Physicists, on the verge of declaring the physical world “understood”, discovered that existing theories failed to describe the behavior of the atom. In a very short time, a more fundamental theory of the ...
The Physics Behind the Power of an Engine Insert the key, turn, and vroom. And down the road you go. Most people take for granted the strange conglomeration of metal and plastic under that sheet of metal, either in front or back of their vehicle. The engine, as you may have guessed, is a modern marvel- so to speak. They’re found in cars, trucks, boats, airplanes.
Finding use in “spacecrafts, pacemakers, underwater systems, electric automobiles, and remote monitoring systems” (source 6), the atomic battery has existed for over a century and is growing to benefit our world. The atomic battery generates electricity from a nuclear reaction, utilizing the radioactive decay of specific elements. The atomic battery is certainly not meant for households or as a source of common battery use, but rather powerful equipment needing to run for long, extended periods. Atomic batteries are quite expensive, but can provide an immense amount of energy that will conduct over an extremely long life period. This paper will explain the basic functioning of an atomic battery, investigate a brief history of the atomic battery, and also examine one aspect of energy conversion within atomic batteries, thermal converters.
The molar specific heats of most solids at room temperature and above are nearly constant, in agreement with the Law of Dulong and Petit. At lower temperatures the specific heats drop as quantum processes become significant. The Einstein-Debye model of specific heat describes the low temperature behavior.
Conduction, convection and radiation are the three methods through which heat can be transferred from one place to another. The (www.hyperphysics.com) first method is the conduction through which heat can be transferred from one object to another object. This process is defined as the heat is transmitted from one to another by the interaction of the atoms and the molecules. The atoms and the molecules of the body are physically attached to each other and one part of the body is at higher temperature to the other part or the body, the heat begins to transfer. A simple experiment through which conduction can be understood easily is as follows. First of all, take a metallic rod of any length. Hold the rod in the hand or at any stand made up of the insulator so that the heat does not transfer to the stand. Heat up the one end of the rod with the help of the spirit lamp. After sometime, touch the other end of the end, the other end of the becomes heated too and the temperature of the other end of the rod has also increased. Although only one end of the rod is heated with the spirit lamp, but the other end of the rod has also been heated. This is represents that the heat has been transferred from one end of the rod to the other end of the rod without heating it from the other end. So, the transformation of the heat is taking place. This process is called the conduction. Conduction is a process which is lead by the free electrons. As the conduction happens occurs only in the metallic materials, the reason for it is that the metals has the free electrons and they can move freely from one part of the body to another part of the body. These electrons are not bounded by the nucleus so, they can move ea...
Conduction, convection and radiation are the three methods through which heat can be transferred from one place to another. The (www.hyperphysics.com) first method is the conduction through which heat can be transferred from one object to another object. This process is defined as the heat is transmitted from one to another by the interaction of the atoms and the molecules. The atoms and the molecules of the body are physically attached to each other and one part of the body is at higher temperature to the other part or the body, the heat begins to transfer. A simple experiment through which conduction can be understood easily is as follows. First of all, take a metallic rod of any length. Hold the rod in the hand or at any stand made up of the insulator so that the heat does not transfer to the stand. Heat up the one end of the rod with the help of the spirit lamp. After sometime, touch the other end of the end, the other end of the becomes heated too and the temperature of the other end of the rod has also increased. Although only one end of the rod is heated with the spirit lamp, but the other end of the rod has also been heated. This is represents that the heat has been transferred from one end of the rod to the other end of the rod without heating it from the other end. So, the transformation of the heat is taking place. This process is called the conduction. Conduction is a process which is lead by the free electrons. As the conduction happens occurs only in the metallic materials, the reason for it is that the metals has the free electrons and they can move freely from one part of the body to another part of the body. These electrons are not bounded by the nucleus so, they can move easily. And when the temperature of the ...
In 1907, Einstein used Planck’s hypothesis of quantization to explain why the temperature of a solid changed by different amounts if you put the same amount of heat into the material. Since the early 1800’s, the science of spectroscopy had shown that different elements emit and absorb specific colors of light called “spectral lines.” In 1888, Johannes Rydberg derived an equation that described the spectral lines emitted by hydrogen, though nobody could explain why the equation worked. This changed in 1913 when Danish physicist Niel Bohr applied Planck’s hypothesis of quantization to Ernest Rutherford’s 1911 “planetary” model of the atom, which affirmed that electrons orbited the nucleus the same way that planets orbit the sun. Bohr offered an explanation for why electrical attraction does not make the electrons spiral into the nucleus. He said that electrons in atoms can change their energy only by absorbing or emitting quanta. When an electron absorbs a quantum it moves quickly to orbit farther from nucleus. When an electron emits a quantum the electron jumps to a closer
The jet engine is a great mechanical piece of engineering. It has been used in almost all aircraft since its invention. This one improvement in aircraft allowed aircraft to fly higher, faster, and more efficient. The turbocharged engine invented by GE was the main building block for other engines. Since its invention, the jet engine has been the workhorse for all jet powered aircraft.
Since the days of Aristotle, all substances have been classified into one of three physical states. A substance having a fixed volume and shape is a solid. A substance, which has a fixed volume but not a fixed shape, is a liquid; liquids assume the shape of their container but do not necessarily fill it. A substance having neither a fixed shape nor a fixed volume is a gas; gases assume both the shape and the volume of their container. The structures of gases, and their behavior, are simpler than the structures and behavior of the two condensed phases, the solids and the liquids
Rolle, K. C. (2005). Thermodynamics and heat power (6th ed.). Upper Saddle River, NJ: Prentice Hall.
Conduction is the process by which heat is transferred from on solid to another. When a solid is heated the molecules inside, which are normally almost static, start to vibrate. When another solid is brought into contact with the heated solid the energy from the vibrating molecules at the edge of the heated solid is transferred to the outer molecules of the other solid.
Looking into the present day and the future, bond enthalpies will play a big role in the scientific world. Breaking bonds between two atoms that have a strong attractive force requires a deal of energy. Which is also why it is an endothermic process, and is true for the opposite in that making a new bond between atoms is an exothermic process.6. Understanding the energy required to break each of these bonds may someday lead to much more conservative ways of going about
When we place two objects with different temperatures in contact with each other, the heat from the hotter object will immediately and automatically flow to the colder object. This is known as conduction. Some objects make excellent conductors of heat while others make poor conductors of heat or excellent insulators. Silver, copper, and gold make excellent conductors of heat. Foams and plastics make good insulators of heat but make poor conductors. Last night for dinner, I made myself a grilled cheese sandwich and a bowl of tomato soup. I heated the soup faster than I cooked the sandwich so I poured the hot soup into a bowl and finished cooking the sandwich. Once I was done cooking, I gabbed the soup bowl and burned my hand. The heat from the soup made the bowl hot. This is an example of conduction.
Fleisher, Paul. Matter and Energy: Principles of Matter and Thermodynamics. Minneapolis, MN: Lerner Publications, 2002.