Методические указания по обучению чтению технической литературы на английском языке по тепломассобмену

1. Дайте перевод следующих существительных, основываясь на значениях глаголов:

to collide – collision to measure – measurement to reduce – reduction

to continue – continuum to determine – determination to interrelate – interrelation to relate - relation

2. Прочитайте текст, найдите в тексте определения таких понятий
как: “свойство”, “давление”, “средняя длина пути свободного пробега /молекулы/”.

3. Переведите текст, обращая внимание на :

а) перевод инфинитива в начале предложения (1-ый абз.); б) перевод причастия с предшествующим союзом (2-ой абз.); в) значения союзов “as”, “since” – т.к., поскольку.

TEXT A: FLUID PROPERTIES AND THE CONTINUUM
1. To understand matter it is necessary to consider its molecules, which are
in constant motion, colliding and rebounding not unlike billiard balls. To describe matter the history of each molecule must be known. This requires knowing each molecule’s velocity and acceleration which is quite impossible except statistically.
In engineering applications, however, we are interested only in the manifestations
of the molecular motion, i.e., what can be sensed and expressed in measurable terms? The answer is properties.
2. A property (an observable quantity) always has the same value when measured under the same conditions, regardless of how those conditions were reached. Consider a small closed container of gas. What happens as the number
of molecules is reduced? The force per unit area on the wall of the container resulting from the collision of molecules, which is the pressure “p”, is decreased, since pressure is the effect of the average force resulting from repeated impacts of the molecules on the wall. There is a point, however, below which a reduction in one molecule produces a pressure which is discontinuous; hence, it is not reproducible when brought to the same conditions, and therefore it is not a property. This occurs when the mean free path of the molecules, the average distance traveled by the molecules between collisions, is of the same order of magnitude as the smallest significant length (the side of the container in the case under consideration). This point where behavior changes determines the lower bound of the continuum. The continuum results from a continuous distribution of matter.

3. A property has meaning only in a continuum. Noncontinuum behavior
is treated in statistical mechanics and the kinetic theory of gases.
4. The property density “p” is defined as the mass per unit volume. Specific volume “v” is the reciprocal of density; that is, v=I/p. Specific gravity “S” is the ratio of the density of a substance to that of pure water at 4⁰C and 76 cm Hg.
5. Temperature “T” is a property which enables us to determine whether two bodies or two adjacent fluid elements are in thermal equilibrium. It is a measure
of the average translational kinetic energy of the molecules. We use the terms “hot” and “cold” in reference to high and low temperatures. Although temperature
is a familiar property, it is difficult to define because the definition must be indirect, through the concept of equality of temperature.
6. The property concentration “w” is of value when dealing with mixtures, such as dye in water or lemon in iced tea. In a diffusing mixture, the mass of individual species per unit volume, mass concentration, may be significant as in the example of having enough sugar in one’s coffee.
7. Properties are interrelated. For example, water and sulforic acid, initially
at the same temperature, will rise in temperature when they are mixed. The amount
of temperature rise depends on the concentration.
8. The interrelation of fluid properties is in the domain of thermodynamics. During the conversion of energy within the fluid or between the fluid
and its surroundings, the condition and motion of the fluid are affected. An equation of state relates the properties of the fluid as it undergoes a change. Fortunately,
for most substances of engineering interest, the equation of state has a simple mathematical form.

TEXT B: MEDIA

Терминология, слова и словосочетания

1. Переведите текст, обращая внимание на пассивную конструкцию
с глаголами “to affect”: The transfer processes are affected by the medium… -
На процессы переноса влияет среда…

2. Обратите внимание на определения слов “solid” и “fluid”; объясните разницу между словами “fluid” и “liquid”. Сравните определения, взятые
из текста, и определения, взятые из словаря Хорнби. SOLID – a firm substance; not liquid or a gas. FLUID – able to flow easily, like water or a gas, not solid, as fluid substances. LIQUID – a substance that is neither a solid nor a gas, e.g. Air is a fluid but not a liquid. Water is both a fluid and liquid.

TEXT B: MEDIA

1. All matter is made up of solid, liquid, or gas or a combination of them. Since the transfer processes are affected by the medium in which the changes occur,
it is imperative to understand the characteristics of each state.
2. A solid is generally thought of as a substance which offers resistance
to change of shape (deformation), whereas, a fluid will deform continuously when subjected to a shearing stress, no matter how small. The mode of resistance distinguishes between a solid and a fluid.
3. A fluid may be either liquid or gas or a combination of the two. Fluids conform to the shape of their container. A liquid has a free surface, but a gas fills
the entire container and has no free surface.
4. We readily think of water and air as fluids, but many other substances which behave quite differently are also fluids, e.g. asphalt, glass. Blood is a fluid whose behavior varies widely, depending upon its content of hemocytes (blood cells), sugar, and plasma.
5. Fluids whose density changes are insignificant in a given process are said
to be incompressible. Under normal conditions liquids are considered incompressible: gases and vapors may be compressible since their density may change considerably.


TEXT C: UNITS AND DIMENSIONS

1. 
   Прочитайте текст без словаря:
   

а) обратите внимание на различие понятий “dimensions” и “unit”; б) сравните метрические и английские единицы мер длины.
TEXT C: UNITS AND DIMENSIONS

A set of basic entities expressing our observations of the magnitudes of certain quantities is known as a dimension. Many units can be used to describe a dimension. For example, 36 inches = 3 feet = 1 yard = 91.44 centimeters.

Inches, feet, yard, and centimeters are units, but they all represent a measure
of length – dimension. In transport processes the basic dimensions are defined
to be force “F”, length “L”, time “T”, temperature “Q”, and mass “M”.

PART II.

TEXT A. Fundamentals of Transport Phenomena
Термины, слова и словосочетания к тексту А

1. 
   Прочитайте текст и дайте ответы на следующие вопросы:
   

1. How does the author explain the difference between lagrangian and eulerian method of analysis? 2. What examples of fields are given in this text? 3. What definitions of such quantities as “scalar”, “vector” and “tensor” are given in this text?
2. Из приведенных ниже значений глагола to involve выберите наиболее подходящее для данного текста.

1. включать в себя; заключать; содержать, подразумевать, предполагать. 2. влечь за собой; вызывать; приводить к ч.л. 3. вовлекать; впутывать, запутывать.
4. погружаться во что-либо. 5. окутывать.

TEXT A: FUNDAMENTALS OF TRANSPORT PHENOMENA
1. We can study transport phenomena from two viewpoints, lagrangian
or eulerian, and it is important to adopt the one which will yield accurate answers
to our physical problems in the most straightforward manner.
2. In elementary solid mechanics the lagrangian method of analysis is used.
It describes the behavior of discrete particles, or point masses, as they move in space. Fundamental laws, such as Newton’s second law, apply directly to the discrete masses under consideration. The same viewpoint can also be used to study transport phenomena, but consider the complexity of describing the behavior of a particle of fluid as it flows through a region in space. Not only is it difficult to follow, but its shape may change continuously. Therefore, it is more advantageous to describe what happens at a fixed point or in a fixed region in space. This method, the eulerian method, allows us to observe phenomena at points of interest rather than trying to follow a particle throughout a region in space, e.g., the temperature at the nose of a rocket, the pressure at an elbow in a water main, the velocity at the tip of a compressor blade. The eulerian method is used primarily here, but whenever results are easier to obtain by the lagrangian method, we shall use the latter.

FIELDS

3. A field is a region where things happen – observable things. We describe
a thermal field in terms of temperatures at various locations, an electrical field
by point potentials, and a fluid field by velocities at different points. An acoustic field produced, say, by a band playing music may cause interactions in the form of dancing. We are a product of our environment, interacting with fields about us.
4. It is possible, that several fields coexist in any given region. An airliner responds to the thrust of its jets (force field), required to overcome the effects
of its gravitational field, while perturbing the ocean of air (aerodynamic field) through which it moves, at the same time being affected very slightly by the polar magnetic field. Interacting fluid, electric, magnetic, and thermal fields influence plasmas. While it is important to be able to predict phenomena resulting from interactions, it is necessary to segregate fields in order to understand their behavior.
5. In studying fields we encounter three types of quantities: scalars, vectors,
and tensors. A tensor is an ordered set of n quantities, say (M₁, M₂, …, M_n). A second-order tensor involves nine components and arises in fields in such quantities as stress and strain. The components are represented by scalars, which require only
the specification of magnitude for a complete description.
6. Many other physical phenomena, e.g., force, velocity, and acceleration, occur in ordered sets of three quantities. These phenomena can be represented by a first order tensor, commonly called a vector. A vector is designated mathematically
as V = V (x,y,z,t) as in case of velocity, or by the use of three scalar components each of which represents its magnitude in one of three orthogonal directions:

Thus a vector possesses both magnitude and direction. Such quantities as temperature, concentration, volume, mass, and energy are scalars. Scalars are zero-order tensors.
7. A continuous distribution of these quantities – scalars, vectors, and tensors – described in terms of space coordinates and time constitutes a field.

TEXT B: TRANSFER PHENOMENA

Термины, слова и словосочетания
1. to transfer – передавать, переносить, перемещать, транспортировать

equilibrium – равновесие

rate – скорость, степень, расход, производительность

2. to happen - случаться

throughout – повсюду

similar – подобный

amount – количество

efflux – истечение, реактивная струя, выхлоп

dye – краска

3. simultaneously - одновременно

flux – поток, расход, массовый расход