Traditionally, engineering activities have been grouped into certain areas of specialization. These originated as civil and military engineering, catering to man’s early needs. Scientific discoveries and their development gave birth to a variety of fields of application such as mechanical, chemical, and electrical engineering. Today the rapid rise of technology is bringing the adequacy of even these widely accepted designations into question in describing specialist areas within engineering. Several of the more commonly accepted categories are described below.
Aerospace Engineering combines two fields, aeronautical and astronautical engineering. The former is concerned with aerodynamics, structure and propulsion of vehicles designed for the flight in the Earth’s atmosphere. The latter relates to flight above the Earth’s atmosphere and involves the design of rockets and space vehicles incorporating sophisticated propulsion, guidance, and life support systems. The day when one man drew his design in chalk on the floor and then proceeded to build it are long past. Today large teams of engineers are needed to cope with the complexity of modern flight vehicles. The design of an aircraft involves a multitude of specialty areas such as stress analysis, control surface theory, aircraft stability, vibration, production techniques and flight testing.
Agricultural Engineering is one of the earliest forms of engineering practiced by man. It uses agricultural machinery, irrigation, and surveying and deals with the many associated problems of crop raising and animal husbandry. Not only are the fundamental engineering subjects such as hydraulics, metallurgy, and structures of importance, but soil conservation, biology, and zoology are also necessary components. It is here tat machines interface with the animal and kingdoms. Challenging problems occur in areas such as land reclamation and efficient utilization, and improved methods of food production and harvesting.
Chemical Engineering encompasses the broad field of raw material and food processing and the operation of associated facilities. It is mainly involved with the manufacture and properties of materials such as fuels, plastics, rubber, explosives, paints, and cleaners. The chemical engineer is well grounded in both basic and engineering chemistry and apart the production of special materials, may be involved in such areas a combustion, recycling of waste products, and air and water pollution.
Civil Engineering is one of the oldest branches of the engineering profession. It covers a wide field, and many subsidiary branches have grown from it. The civil engineer is mainly employed in the creation of structures such as buildings, bridges, dams, highways, harbors, and tunnels. He is usually knowledgeable in hydraulics, structures, building materials, surveying, and soil mechanics. One important area comprises water supply, drainage, and sewage disposal. More than any other branch of engineering, the results of the civil engineer’s efforts are the most visible in a permanent form.
Electrical Engineering, in general, deals with creation, storage, transmission and utilization of electrical energy and information. Most of its activities may be identified with power or communications. Electrical engineering is of recent origin, dating back only to the eighteenth century, when electrical phenomena were first subjected to scientific scrutiny. After this, useful applications were quickly identified. Today, the impact of a power failure graphically illustrates our dependence on electrical power. The field encompasses information systems, computer technology, energy conversion, automatic control, instrumentation, and many other specialties.
Industrial Engineering is mainly concerned with the manufacture of useful commodities from raw materials. Since most of the other engineering fields have a bearing on this activity, the industrial engineer requires a particularly broad view. The management of men, materials, machines, and money are all within his endeavor in achieving effective production. Plant layout, automation, work methods, and quality control are included, and, more than in most of the other traditional branches of engineering, the industrial engineer needs to have some grounding in psychology and dealing with personnel.
Mechanical Engineering develops machines for the generation and utilization of power. Mechanical engineers design turbines, engines, pumps, and their ancillary mechanisms and structures. Heating, ventilating, airconditioning, transportation, manufacturing, and vibration are some areas falling within their domain. The art of mechanical engineering dates back to the labor-saving devices and military machines of ancient times, but it received its greatest boost in the eighteenth century with the invention of the steam engine and industrial machinery, which marked the onset of the industrial revolution.
Mining and Metallurgical Engineering. The production and use of metals, has two distinct branches. One deals with the location, extraction, and treatment of ores to obtain base metals, and the other with the transformation of these metals into useful forms and with the study of techniques for improving their performance in specific applications. The study of ceramics is often included in this field. Special topics range all the way from materials that may be used with living tissue to the development of composites for high-temperature applications such as in the heat shields used for satellite reentry.
In addition to the fields identified above, other categories of engineering are often encountered. These include architectural, ceramic, geological naval and marine, nuclear, petroleum, sanitary, and textile engineering.
TEXT 18. Engines
Do you know what the first engine was like? It was called the “water wheel”. This was an ordinary wheel with blades fixed to it, and the current of a river turned it. These first engines were used for irrigating fields. Then a wind-powered engine was invented. This was a wheel, but a very small one. Long wide blades were attached to it. The new engine was driven by the wind. Some of these one can still see in the country. Both of these, the water- and wind-operated engines are very economical. They do not need fuel in order to function. But they are dependant on the weather.
Many years passed and people invented a new engine, one operated by steam. In a steam engine, there is a furnace and a boiler. The furnace is filled with wood or coal and then lit. The fire heats the water in the boiler and then it boils, it turns into steam which does some useful work. The more coal is put in the furnace, the stringer the fire is burning. The more steam there is the faster a train or a bout is moving.
The steam engine drove all sorts of machines, for example, steam ships and steam locomotives. Indeed, the very first aeroplane built by A.F. Mozhaisky also had a steam engine. However, the steam engine had its disadvantages, It was too large and heavy, and need too much fuel. The imperfection of the steam engine led to the design of a new type. It was called the internal combustion engine, because its fuel ignites and burns inside the engine itself and not in a furnace. It is smaller and lighter than a steam engine because it does not have a boiler. It is also more powerful, as uses better-quality fuel: petrol or kerosene.
The internal combustion engine is now used in cars, diesel locomotives and motor ships. But to enable airplane to fly faster than the speed of sound another, more powerful engine was needed. Eventually, one was invented and it was given the name “Jet engine”. The gases in it reach the temperature of over a thousand degrees. It is made of a very resistant metal so that it will not melt.
