English terminology of aircraft engines: lexical-semantic, structural-grammatical and pragmatic features.

Solovyeva Alexandra Educator, Department of foreign languages, Syzran branch of the Military Educational and Scientific Center of the Air Force of the "Air Force Academy named after Professor N. E. Zhukovsky and Y. A. Gagarin"  ul. marshala Zhukova 320- 66, Samarskaya oblast, Syzran, Russia sandraS91@yandex.ru Other publications by this author

The description of the essence of the term is one of the most urgent tasks of modern linguistics. Attempts to give an accurate definition of the concept of “term" have been made many times. In the works of such scientists as Averbukh K.Ya., Golovin B.N., Kobrin R.Yu., Grinev S.V., Danilenko V.P., Kandelaki T.L., Leychik V.M., Superanskaya A.V., Akhmanova O.S., Volodina M.N. various aspects of the issue are considered, but they are all united by one thing - the recognition of the term a complex and multidimensional phenomenon that requires an integrated approach to study.

Reflections on the topic “What is the term?” they led to the emergence of a number of definitions that differ from each other to varying degrees. Here are some of them. The term is:

- “an element of terminology (term system), which is a set of all variants of a non-linguistic sign or a steadily reproducible syntagma expressing a special concept of a certain field of knowledge” ^[1];

- “a word or phrase of a special sphere of use, created (borrowed, accepted) for the exact expression of special concepts and based on a definition” ^[3];

- “a verbalized result of professional thinking, a significant linguistic and cognitive means of orientation in the professional sphere and the most important element of professional communication” ^[4];

- “a word or subordinate phrase having a special meaning, expressing and forming a professional concept and used in the process of cognition and development of scientific and vocational objects and relations between them” ^[5];

- “a nominative special lexical unit (word or phrase) of a special language, accepted for the exact naming of special concepts” ^[6];

- “a word (or phrase) of a special sphere of use, which is the name of a special concept and requires a definition” ^[7];

- “a word or lexicalized phrase that requires the construction of a definition in order to establish its meaning in the corresponding system of concepts" ^[8];

- “a lexical unit of a language for special purposes, denoting a general – concrete or abstract – concept of a theory of a certain special field of knowledge or activity" ^[9];

- “a special word (or phrase) adopted in professional activity and used in special conditions; a verbal designation of a concept included in the system of concepts of a certain area of professional knowledge; the main conceptual element of the language for special purposes; requires a special definition (precise scientific definition) for its correct understanding” ^[10].

All of the above formulations, without a doubt, have high scientific value, make a significant contribution to the development of the theory of the term. As the basis of our research, we chose the definition (proposed by S.D. Shelov), according to which:

 - “a language sign (a word, a phrase, a combination of a word or a phrase with special symbols, etc.) expressing the concept of a field of knowledge and therefore having a definition (interpretation, explanation), which is consciously guided by those using this language sign, is a term;

- “a language sign (a phrase, a combination of a word or phrase with special symbols, etc.) is a term if it expresses the concept of any field of knowledge and is motivated by language signs (words, phrases, a combination of a word or phrase with special symbols, etc.), at least one of which is its (lexicosyntactic) part, expresses a special concept of the same field of knowledge and is recognized as a term by virtue of clause 1.” ^[11].

In our opinion, this definition most fully characterizes the essence of the term in the context of the terminology of aviation gas turbine engines analyzed by us. The latter is a very specific layer of terminology, in the structure of which the following semantic groups can be distinguished:

1. Types of gas turbine engines (single-shaft, two-shaft, three-shaft, lifting, marching, lifting-marching, auxiliary, turbojet, turboshaft, turboprop).

2. Design of gas turbine engines (gearboxes and drives, air intake, compressor and turbine, combustion chamber, automatic control systems, lubrication systems, cooling system, starting system) ^[12].

Within the framework of this study, 309 terminological units were analyzed. They are represented by both one-word terms and word combinations. Let's consider the structural, semantic and pragmatic features of terminology in each semantic group.

1. Types of gas turbine engines.

The terms of this group are multicomponent (two-, three-, four- and five-component) phrases that consist of nouns, adjectives and numerals. Two-component terms are formed according to the NN (noun+noun) model, for example, turboshaft engine (turboshaft engine), turboprop engine (turboprop engine), turbojet engine (turbojet engine), etc. Their share in the total number of multicomponent terms of the group is 20%.

To form three-component terms (20% of the total number of terms in the group), models are used:

1. NNN (noun+noun+noun) - gas turbine engine (gas turbine engine), afterburning turbojet engine (turbojet engine with afterburner combustion chamber)^{[12, 13]} and others.

2. ANN (adjective+noun+noun) - pure turbojet engine (turbojet single-circuit engine)  ^{[12, 13]} and others.

Four-component terms within this group make up the majority (35%). Structurally , they are designed as follows:

1. NNNN (noun+noun+noun+noun) - lift gas turbine engine (lifting gas turbine engine), cruise gas turbine engine (mainline gas turbine engine) ^{[12, 14]}, etc.

2. ANNN (adjective+noun+noun+noun) - auxiliary gas turbine engine (Auxiliary gas turbine engine), etc.

3. NumNNN (numeric+noun+noun+noun) - three flow turbojet engine (turbojet three-circuit engine) ^{[12, 14]}, etc.

The second largest number in the group “types of gas turbine engines” is occupied by five-component terminological phrases (25%). The following models are involved in their education:

1. NumNNNN (numeric+noun+noun+noun+noun) - one shaft gas turbine engine (single-shaft gas turbine engine) ^{[12, 15]}, etc.

2. NNNNN (noun+noun+noun+noun+noun) - lift cruise gas turbine engine (lifting and marching gas turbine engine), etc.

3. NANNN (noun+adjective+noun+noun+noun) - aircraft auxiliary gas turbine power plant (auxiliary power plant of the aircraft) ^{[12, 15]}. The analysis showed that three-, four- and five-component terms-phrases are formed on the basis of the original two-component, functioning as independent terms, by adding defining components to them (turbine engine?gas turbine engine?regenerative gas turbine engine?one shaft gas turbine engine).

Next, we will focus on the issues of synonymy and ambiguity of the terms of this group. The study allowed us to conclude that the terminology used to describe the types of aircraft engines meets the requirement of unambiguity. At the present stage of the analytical work, it was not possible to identify cases of terminological ambiguity in this group of vocabulary. Moreover, the existence of synonymous relations between units has not been established. It can be said, therefore, that the terms are close to ideal, if based on the criteria of “ideality” of the term, which are postulated in many works devoted to terminology issues ^[6].

In terms of pragmatics, the following should be noted. Firstly, the terms of this group represent a way of implementing scientific knowledge ^[2], reflecting the essential characteristics of various types of engines. Secondly, the terms contain information that regulates and directs the activities of specialists in the field of operation and production of engines of a specific type. Thirdly, this information is encoded using specific term elements that form complex multicomponent equivalents of words - terminological phrases.

The analysis of the structure of the terms of this group showed that such term elements are nouns, adjectives and numerals. A number of nouns (turboprop, turbojet, turboshaft) indicate that the typology of engines is based on the principle of their operation. In the case of a turbojet, the fuel energy is converted into the kinetic energy of the gas jet flowing from the jet nozzle ^[12]. A turboprop engine is an engine in which the output shaft power is used to drive a pulling screw (prop is short for propeller) ^[12]. In a turboshaft engine, the predominant share of fuel combustion energy is converted into output shaft operation ^[12].

The nouns lift, cruise encode information that engines are classified by purpose, depending on the sections of the flight path that they provide. Thus, the lift gas turbine engine (lifting gas turbine engine) is designed to provide transitional sections of the flight path, and the cruise gas turbine engine (cruise gas turbine engine) is designed to provide the main section of the flight path ^[12]. 

The adjective auxiliary indicates to the specialist that the auxiliary gas turbine engine is intended for auxiliary purposes. As for numerals, they encode the design features of various types of engines: one shaft (single shaft, with one shaft), two shaft (two shaft, with two shafts), three shaft (three shaft, with three shafts) ^[12].

It is believed that terminological information can be misleading ^[2] due to the fact that the lexical and conceptual meaning of the term are not always compatible. In the context of the terminology of the group “types of aviation gas turbine engines”, no such cases have been identified. Terminological information embedded in two-, three-, four- and five-component phrases can be considered correctly orienting, which, in turn, contributes to its adequate assimilation, interpretation and use in achieving specific goals in the process of professional communication and activity.

2. The design of gas turbine engines.

The terminology of this group is represented by both one-word terms and word combinations. One-word terms make up 4.6% of the total number of units in the group, multi-word terms make up 95.6%. One-word terms, as a rule, are borrowings from automotive terminology (for example, compressor - compressor). Wordy terms are represented by two-, three-, four-, five- and six-component phrases. Among them, three-component units occupy a dominant position (39%). The following models are involved in their education:

1. ANN (adjective+noun+noun) - variable-geometry inlet (adjustable air intake), subsonic compressor stage (subsonic compressor stage), centrifugal compressor stage (centrifugal compressor stage)  ^{[12, 13]} and others.

2. NAN (noun+adjective+noun) - turbine transonic stage (transonic turbine stage), turbine partial stage (partial turbine stage)  ^{[12, 13]} and others.

3. NNN (noun+noun+noun) - combustion chamber diffuser, flame tube head (front device of the combustion chamber), sound suppression nozzle (jet nozzle with muffler)  ^{[12, 13]} and others.

4. NumNN (numeric+noun+noun) - two spool compressor (two-stage compressor), one stage turbine (single-stage turbine)  ^{[12, 13]} and others.

Two-component terminological phrases occupy the second place in terms of prevalence (25.5%). They are formed according to models:

1. AN (adjective+noun) - subsonic inlet (subsonic air intake), supersonic inlet (supersonic air intake), centrifugal compressor (centrifugal compressor) ^{[12, 15]}, etc.

2. NN (noun+noun) - compressor stage (compressor stage), combustion chamber (combustion chamber of a gas turbine engine), nozzle vane (nozzle blade) ^{[12, 15]}, etc.

Four-component terms and phrases (21.3%) are structured as follows:

1. NNAN (noun+noun+adjective+noun) - turbofan engine primary flow (internal circuit of a turbojet two-circuit engine),turbofan engine secondary flow (external circuit of a turbojet two-circuit engine) ^{[12, 15]}, etc.

2. AANN (adjective+adjective+noun+noun) - supersonic external compression inlet (supersonic flow external compression air intake), conical supersonic jet nozzle (conical supersonic jet nozzle) ^{[12, 15]}, etc.

3. ANNN (adjective+noun+noun+noun) - axial compressor stage rotor (compressor stage impeller), direct impingement starting system (starting system with direct compressed air supply) ^{[12, 15]}, etc.

4. NNNN (noun+noun+noun+noun) - compressor stage guide vanes (axial compressor stage guide), compressor inlet guide vanes (compressor inlet guide), combustion chamber transition liner (combustion chamber gas collector) ^{[12, 15]}, etc.

5. ANAN (adjective+noun+adjective+noun) - centrifugal compressor vaneless diffuser (bladeless diffuser of the centrifugal compressor stage), centrifugal compressor varied diffuser (bladeless diffuser of the centrifugal compressor stage) ^{[12, 15]}, etc.

6. NNwithAN (noun+noun+with+adjective+noun) - turbine stage with subsonic rotor (subsonic turbine stage), thrust reverser with rotating cascade (reversing device with deflecting grids) ^{[12, 15]}, etc.

7. NNinNN (noun+noun+in+noun+noun) - fan turbine in turbofan engine (fan turbine of a two-circuit gas turbine engine) ^{[12, 15]}, etc.

5 models are used to form five-component terms (7.8%):

1. NNNNN (noun+noun+noun+noun+noun) - turbofan engine add compressor stage (retaining stage of a two-circuit gas turbine engine), inlet boundary layer control system (control system of the boundary layer in the air intake) ^{[12, 15]}, etc.

2. NNofANN (noun+noun+of+adjective+noun+noun) - afterburning channel of augmented turbojet engine (afterburner circuit of a turbojet engine with afterburner chamber) ^{[12, 15]}, etc.

3. NANNN (noun+adjective+noun+noun+noun) - compressor variable inlet guide vanes (adjustable compressor inlet guide) ^{[12, 15]}, etc.

4. ANNNN (adjective+noun+noun+noun+noun) - variable compressor stage guide vanes (adjustable guide device of the axial compressor stage), cold gas turbine engine start (cold gas turbine engine start) ^{[12, 15]}, etc.

5. AANNN (adjective+adjective+noun+noun+noun) - solid propellant gas turbine starter ^{[12, 15]}, etc.

The structure of six-component terms (1.6%) can have the form:

1. NNofNNNN (noun+noun+of+noun+noun+noun+noun) - cooling system of gas turbine engine component (gas turbine engine unit cooling system) ^{[12, 15]}.

2. NNNNNNN (noun+noun+noun+noun+noun+noun+noun) - gas turbine engine air gas channel ^{[12, 15]} (flow part of a gas turbine engine).

3. ANofNumNNN (adjective+noun+of+numeric+noun+noun+noun) - intermediate flow of three flow turbojet engine (intermediate circuit of a turbojet three-circuit engine) ^{[12, 15]} .

The analysis showed that two-, three-, four-, five-, and six-component terminological phrases of the group are formed on the basis of the original one-component terms - words that function independently by adding defining components to them (inlet?supersonic inlet?supersonic external compression inlet; vanes?guide vanes?inlet guide vanes?compressor variable inlet guide vanes). In addition, it should be noted that, like the terms of the first group, the terms that are used to describe the design of engines are unambiguous. At this stage of the study, it was not possible to establish cases of ambiguity. As for synonymy, in the second group of terms we identified only 3 examples illustrating the presence of this type of semantic relations in terminology: vane=blade; cold gas turbine engine start= cold gas turbine engine starting; hot gas turbine engine start=hot gas turbine engine starting.

The pragmatic features of the terminology of the group can be reduced to several provisions:

1. The terms are a way of implementing scientific knowledge reflecting the specifics of the design of gas turbine engines and their components.

2. The terminology contains information that guides the activities of specialists in the field of production and operation of engine components.

3. This information is encoded using term elements, which (as in the first group) are adjectives, nouns and numerals.

Thus, the adjectives external, internal, mixed indicate to the specialist in which parts of the supersonic air intake the air flow is compressed. In the case of an external compression air intake (supersonic external compression inlet), compression is carried out in front of the inlet plane. In the air intake of internal compression (supersonic internal compression inlet), it occurs inside the channel. The air intake of mixed compression (supersonic mixed compression inlet) assumes compression both in front of the plane of entry into the air intake and inside its channel ^[12]. The adjectives subsonic, supersonic encode information about the speeds of the incoming air flow at which one or another type of air intake operates. Subsonic air intake (subsonic inlet) is designed to operate at subsonic (subsonic) speeds, supersonic (supersonic inlet) is designed to operate at supersonic (supersonic) speeds ^[12]. Combinations of numerals with nouns (two spool compressor, three spool compressor, one stage turbine) are intended to indicate the design features of the main parts of the engine: two spool compressor (two-stage compressor, i.e. consisting of two (two) cascades (spool)), three spool compressor (three-stage compressor, i.e. consisting of three (three) cascades (spool)), one stage turbine (single-stage turbine, i.e. a turbine having one (one) stage) ^[12].

It is important to note that in the context of the terminology of the group “design of gas turbine engines” (as well as in the terminology of the group “types of gas turbine engines”), there were no cases of false orienting information. Terminological information embedded in one-, two-, three-, four-, five- and six-component terms is correctly orienting. This, in turn, means its adequate interpretation and effective use for solving professional tasks.

Thus, our study of the English terminology of aircraft engines allowed us to draw a number of significant conclusions:

1. Terminology is a set that includes both single-word and multicomponent terms. The latter make up the majority (with the dominance of three- and four-component phrases).

2. The phenomena of synonymy and ambiguity are not widely used in the terminology under study.

3. Multicomponent terms - phrases are formed from one-component and two-component units functioning as independent terms by attaching defining components expressed by adjectives, nouns and numerals.

4. With the help of the latter, terminological information about the types and design features of aircraft engines is encoded. This information is correctly orienting, it directs the activities of specialists engaged in the production and operation of aircraft engines of various types.