MODELLING OR MODELING? By themselves, these words are used sometimes as synonyms, today do not surprise anyone, as our readers — even more so. Every young technician had used them many times and about. And maybe just because our reader in the most direct way the creative labor involved in its models, modeling and modeling, it is useful to carefully talk about it.
What is the model, when she appeared, where and what is used, what is the value in engineering and science, upbringing and education? These and many other questions can be put in front of us is so simple, it would seem at first glance, the technical concept.
First, let’s understand: what is a model?
Guys at such a “naive” question usually answer that the model is a reduced copy of ship, plane, car, rocket or some other moving of the representative of the world of technology. Then usually clarifies the functional side of the case and the degree of similarity with the original, the prototype: a model or a working table, a schematic, a copy or semi-copy of the racing — flying, swimming, running…
From table top models any movement is not required, its purpose. is to give us information only about the appearance of the object to tell how it looks from the outside. These are in the majority, for example, models of sailing ships, vintage automobiles or… jet planes!
It is not excluded that a simple piece of wood with reinforced it with a piece of bark served as a men’s model first sailboat.
The so determined properties are formidable fighting machines.
It would seem strange neighborhood: Columbus ‘ Caravel and the supersonic fighter! But people called modelers, these things nevertheless, it is considered approximately equal — just like the desktop models (they are also called layouts). Model sailboats make, as a rule, naplavki and jet flying. And that is their own, very valid reasons.
The thing is that marine, aviation and. other modelers is. people who must compete with each other: whose model will be faster the distance will make bigger circles in flight, above, rises into the air, farther, and more accurately swims under water? For all these indicators is charged a certain number of points and in accordance with the places in the competition.
Vintage sailboats in terms of competition in the race do not participate, and for the same reason, almost do not fly model jets. The latter has, however, a special for the occasion; not yet mass production model jet engines, and manually producing them is very difficult. People who build miniature flying machines, reduced many times boats, cars, space rockets and then make all this homemade microtechnology to swim, drive, fly, participate with her in competitions for agility and skill, and call us modelers. Regardless of age, profession, occupation. The view of such technical performances referred to as models (not simulation!) and refer it to the category of technical sports.
GREAT IDENTITIES
It seems that the concept of modelling does not require further explanation, as our readers know his essence from my own experience and on publications of the journal. Let us return to the model itself. This word occurs. from the Latin “modus”, “modulus”, which means “measure”, “image”, “method”, etc. Its original meaning was connected with the building art, and almost always it was used to denote a sample, a prototype or things that are similar in some respect to another thing. It is quite possible that this is the most common meaning of the word “model” was later the basis for using it as a scientific term in the technical, natural, mathematical, social and other Sciences.
It is unlikely that today remained on the Ground, at least one area of knowledge in which scientists are somehow not operated would term “model”. We’ll restrict our conversation technique and technical Sciences. With regard to him can agree that a model of any object, phenomenon or process, we will refer to a different object, a different phenomenon or different process, with similarities and common patterns. And touch a bit of history.
In the sixteenth century, the English physicist and physician William Gilbert first suggested that the Earth is a big magnet. To prove his theory the scientist had built a model of the Earth — magnetized iron ball, which he called terelli, that is, little earth. Hilbert showed that a magnetic needle on the surface of the ball behaves about the same as on the surface of the Earth. Hence, the scientist concluded that the Earth is a giant natural magnet. Moreover, due to this discovery he put forward the hypothesis (which was confirmed many years later) that the magnetic pole of the Earth coincides with the geographic.
Water-lifting wheel, increased tenfold, the century will be the ally of the farmer.
Model helicopters were built in the middle ages.
Using an iron model of the Earth and the magnetic needle, Gilbert, based on commonality (similarity) phenomena has made its conclusion on unity of the reasons, them causing. But for the second is not necessarily the adequacy of the material, which comprises the model and the prototype. Therefore, we cannot say that the experience of Gilbert corresponds to the true nature of things, as the Earth consists not only of iron but also of many other heavy elements.
It is known that great attention was paid to the issues of modeling and Leonardo da Vinci. The movement of the swimmer, the influence of wind on the flight of birds, the work of human muscles and animals were to him the object of careful study. Based on observations, scientists build models and were judged on the objects and phenomena. So, in an effort to comprehend the Laws of falling bodies, Leonardo wrote in the notebook of the task himself: “tomorrow Make the figures falling in the air, different, shapes from cardboard that you throw our bridge. Then sketch the shapes and movements that describes each of them in his fall on different parts of its path.”
Using a specially constructed model of a scientist trying to identify the role of the tail of the bird during its flight: “Let it be dangling here like a bird whose tail is rotated with a different inclination. With the help of this body you can give General rules for the various turns of the birds in the case of movements by bending their tail.”
A kite, invented many millennia ago, is essentially a “model” for the main part of the aircraft wing. The same laws of aerodynamics to explain the principle that can rise into the air a huge plane and simple children’s toy — a sheet of paper with a thin wooden frame .and a long tail.
Curiously, the Great encyclopedia, published in Russia in the beginning of this century, classifying known at that time directions of development of aircraft, says literally “snakes or airplanes; they uplift occurs due to the combined action of the engine and inclined surfaces”. It is natural that in the years of the first timid steps of the aircraft, in cosmolene time of flying snakes may be considered as the airplane, were the main source of experimental data and knowledge about the flight of heavier-than air. Flying on such structures was extremely risky, and their creators usually tried your design first on a small models, and then proceeds to the test of real aircraft.
Models of aircraft built in Europe in the late nineteenth century.
“Kepten” turn over!” warned Reid.
The model of the icebreaker “Yermak” in the testing tank are proposed pool.
Excellent flying model, for example, constructed in 1876, inventor of the first airplane, A. F. Mozhaisky. The engine model is equipped with three small propellers, served as a clock spring, the factory key. Launched by the hand of the inventor, the model is run on the table, easily rose into the air. Present during this experience it seemed incredible that a mechanical toy is heavier than air, having filled with light gas cylinder, as in an airship or balloon, able to fly.
Flying models at all stages of the development of aviation played a vital role as a tool of experimental research.
THE CRITERION OF TRUTH!?
The construction of models of practice, and the latter, as is known, serves as the main criterion of truth in cognition. Evidence in the history of science and technology innumerable. The most convincing of them are the most known, has become a “classic”. Sometimes such a fame gains at the cost of great human tragedies. Here is just one such example.
In London St. Paul’s Cathedral more than a hundred years ago, he installed a bronze plaque begins with the inscription; “the Eternal condemnation of the ignorant obstinacy of the lords of the Admiralty…” the ignorance of the aristocracy, administers all Maritime Affairs of the Empire, in this. the case has cost the lives of 533 English sailors who died along with his ship in 1870.
“Captan” — a new iron battleship of the British Navy — the idea of the author of the project of captain Kolza had to combine many important for vehicle quality. His side defended from enemy shells, especially thick armor on the deck stood a menacingly armored rotating turret. To reduce the possibility of the enemy’s shells, the freeboard of the ship has made less than half that of other battleships. Like many warships of those times, “Captan”, except for steam engines, which resulted in the action of propellers, and had a full sailing rig. But to eliminate the guy that prevented the guns have high angle of attack, the ship was equipped with a heavy three-legged mast.
After reviewing the project “Catena” chief naval engineer of the British fleet, Reid refused to approve it: the battleship is too highly placed heavy loads, low freeboard, large sail, small width. But the teachings about the ability of the ship to safely withstand the roll, the doctrine of stability in those years did not exist, and no one wanted to listen to the voice of reed, to believe his calculations. Then Reid, anticipating an irreparable disaster, began to seek new evidence. He made a model of “Catena” and checked how the new fancy battleship will behave on the water. The results of the experiment confirmed the fears of the engineer, but they, despite all the efforts of reed, did not help to overcome the obstinacy of the lords. The Admiralty decided to send a ship to sea in the composition of the armored squadron.
The future of the giant liner “grows” from the model, which is freely placed on the table surface.
Real brass disk (1) and ideal (mental) models: 2 — shaped, painted and 3 — iconic, written as a formula the area of a circle.
The ideal model, familiar from school chemistry textbook:
1 — model of a molecule of benzene; 2 —it figuratively-sign (mixed) model, showing the shape of valence bonds in molecules; 3 — iconic model of the benzene formula.
On the morning of 6 September 1870 “Kepten” took start sailing race in the Atlantic ocean: a kind of contest was to identify the driving characteristics of armored ships under sail. And at dawn the next day, when by order of the Admiral, all ships came together, it turned out that “Catena” no. A search began. In the ocean discovered its wreckage and near the Spanish port — the boat with eighteen crew members of the ill-fated battleship. The officer and the sailors said that “Captan” there was a big roll and the edge of its right side touching the water. When the wind increased, the ship tilted even more, was commanded to clean up and the last sail. But the team did not have time to perform the battleship went overboard on water, then capsized keel up and sank together with the crew.
The court handling the case of the death of “Catena”, issued a condemnation of the stubbornness of the ignorant lords of the Admiralty and decided to engrave his sentence on a bronze plate, bistabil its public display in the Cathedral for the edification of posterity.
After the death of “Catena” the results of experiments with reed models and the resulting calculations were published in the press. Many shipbuilders stability of ships began to assess a “reed chart”.
In 1871, another English engineer, William Froud, offered a kind of testing of models and recalculation of their results to determine the resistance of the ship environment. He also recommended to build a special pool-the facility in which the shipbuilders were able to Conduct experiments with models of future courts, to identify their quality before construction.
Great attention was paid to the modelling of Russian inventors and scientists. It is known that at. models tested the principle, kinematics, reliability of their inventions A. K. Nartov, I. I. Slides, I. P. Kulibin, and many others. So, in 1738, in a letter to the Academy of Sciences of the Narts reported about the invention of new machines for drilling of guns and for cutting screws, and requested that he “was commanded to write pomenutih Mahin make models and making these models… detailed description of the machine of the Academy of science to apply”.
Already in the early XVIII century in Russia was considered mandatory to check the validity and efficiency of the pre-invented machinery to build their models. The model was tried on the merits and demerits, efficiency, readiness of the design for implementation into production, possible ways of its improvement. The quality of the models were presented to a very high standard. Often they are implemented in force, to be able to judge the reliability of the new machines in operation. The model was subjected to a thorough examination, on the basis of inspection or tests made conclusions about the value of inventions.
To using models are often used Mikhail Lomonosov and L. Euler. Outstanding Russian shipbuilders academician. Krylov and the Admiral S. O. Makarov thought of modeling one of the major methods of experimental research. In particular, a comprehensive analysis and study they both criticized at the time, the model of the famous icebreaker “Ermak”, built by S. O. Makarov. Using it was detected early, many important features and updated capabilities of the most powerful at that time icebreaker.
Developing and improving over the years, modeling has firmly occupied in science and technology the role of one of the most important methods of obtaining new knowledge about the laws and processes of nature. It serves as a valuable tool for the development and creation of new, unprecedented and machines, equipment and new technological processes.
And what is a simulation? What it represents as a process?
A LITTLE PROLOGUE
Of the many interpretations of modeling, proposed by various authors in different years and in different countries, the most successful is the definition given prominent Soviet scientist, academician L. I. Sedov. “Simulation,” he writes, ” this is the replacement study we are interested in phenomena in nature, the study of similar phenomena on the model of lesser or greater magnitude, usually in a special laboratory. The main point of the simulation is that experiments with models could provide the needed answers about the nature of the effects and of the different quantities related to the phenomenon in situ”.
If you follow this idea of modeling, and to the very concept of the model will have to be very respectful, to clarify the boundaries of its application.
In everyday life you can hear the expression: “came off the Assembly line another model car”, “Demonstrate new models of clothes”, or a sign of a Shoe shop “Repair shoes”. And certainly not everyone realizes that in this case we are talking not about the models, but only the varieties or finished product samples that the models have a relationship any more than, say, the designer—the person who creates new styles of clothing — from engineers to experiment with the model of the future ship or aircraft. It almost no, only a coincidence applicable terminology without considering its true meaning.
Numerous family of models used in science, technology, public practice, depending on the method of their construction, from the media, which is the modeling of the studied objects, divided into two large classes: 1st — the material (real, real, existing) and the 2nd — ideal (imaginary, speculative, mental).
MODEL IMAGES AND PATTERNS-SIGNS
In the creative process of the material model are inextricably linked with the ideal, the imaginary, as before to build a model of any materials, persons mentally imagines her design, is theoretically justified, expects future technical device: draws sketches, preparing drawings, making calculations. Karl Marx said that “the worst architect from the best bee from the beginning, distinguished by the fact that before building a cell from wax, he had already built it in my head. At the end of the labor process we get a result that already in the beginning of this process there were representation of a human, i.e. perfect.”
These words of Marx are quite applicable to the characterization of the mental (ideal) models. Last, before they come to reality (metal, plastic, wood, etc.) and will become due to creative human labor, the material, originally exist in the human imagination as the images of real objects as their theoretical schemes.
Ideally, mental models and distinguish klassificeret into separate groups. Among them we can distinguish two main: group shape and group landmark models. The first is the ideal model, which in the view of mentally constructed from the familiar “sensory-intuitive” elements, figuratively similar to those that exist in environmental engineering. For example, these imaginary levers, springs, flows of liquids and gases, the motion of bodies on trajectories, etc. They can be locked in the form of technical drawing, drawing, sketch, diagram, and in a sense are clear. “Whatever people may think, wrote about this outstanding Russian physicist N. A. Minds — the ideas or images of reality, as those and others have one common origin — the area of feelings… Our destiny is the creation of pictures, moving panoramas, shapes, images — in short, models of the existing and done, do not contradict each other, and bound together”. In this sense, the section drawing of the internal combustion engine can serve as a vivid model of the real engine. A popular scientific cartoon explaining, say, the phenomenon of electromagnetic induction, is a moving, imaginative model of this physical phenomenon.
The second group — iconic models — are ideal, mental models in which elements, relations and properties of phenomena are expressed by a system of signs: formulas, graphs, tables, etc. a Feature of such models is the complete lack of resemblance between their elements and the corresponding elements of the real object. For example, any coin has no resemblance with the formula of area of a circle πR2, although the latter can be considered as a symbolic model of the coin, a real metal disc of specific diameter.
In addition to the figurative and symbolic of the ideal models in this class provide a further intermediate — shaped symbolic models that are characterized by features of both the first and second main types of mental models. They combine iconic elements (for example, the chemical symbol for the atom, and the valence band touch, indicating a chemical bond between atoms) with a spatial image that is regarded as geometric similarity of the spatial structure of real molecules. An example of this is the model of benzene in the form of a hexagon, shown in the lower figure. Another compelling example of imagery and iconic models can serve us all well-known ordinary geographical map, which in the form of signs, conventional symbols and diagrams beautifully modeled to scale some part of the surface of our planet with its population, industry, climate, vegetation and other features.
Talk about the perfect (mental) models, mostly living in our imagination or on paper, this is possible and finish. Here are some received ideas about the existence of such models can be useful later when we will talk about designing, creating physical models. In the future we will be mainly interested in the technical model is the real stuff: a small experimental design of future machines, devices, apparatus and other equipment that are created in scientific laboratories and design offices,> in clubs and clubs of young technicians, private enthusiasts technical search and whole creative teams. This type of modeling — technical — the story in the following article.
Yuri STEPANOV
