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Unit 2 fluid mechanics

Fluid mechanics is the discipline concerned with the behavior (movement / conduct) of liquids and gases at rest or in motion.

Lead-in

Free writing: Write down everything that comes to your mind about FLUID MECHANICS. Write only words. If you don’t know the English term, write down the Russian one. You have ONLY 1 minute to do it!

1. Pronounce the following words. Pay special attention to the letters in bold.

conduit

laminar

duct

turbulent

device

roughness

elbow

profile

restrain

finite

shear

transient

gradient

excessive

pressure

channel

cavitation

momentum

2. Pay attention to the stress in the following words. □ shows the position of stress.

device □ restrain □ laminar□ tur□bulent veloc □ ity pro□file

momen □tum mol□ecule cavita□tion repair□ relief□

replace□ment excess□ive expel□ collaps□ing reverse□

3. Read the following mini- texts, do the exercises. Typical Pipe System Components

The transport of a fluid (liquid or gas) in a closed conduit (commonly called a pipe, if it is of round cross section) or duct (if it is not round) is extremely important.

Some of the basic components of a typical pipe system are depicted in Fig. 1. They include the pipes themselves, various fittings used to connect the individual pipes to form the desired system, the flow rate control devices (valves), and pumps (turbines) that add energy to or remove energy from the fluid.

Outlet - выпуск

Pipe - труба

Valve - клапан

Tee - тройник (сидинг)

Elbow - коленo

Inlet - пуск

Pump - насос

Fig. 1. Typical pipe system components

In general, fluids have a well-known tendency to move or flow. It is very difficult to restrain fluid from moving. The slightest shear stress will cause fluid to move. Similarly, appropriate imbalance of normal stresses (pressure) will cause fluid motion.

Terms and Vocabulary

fluid

флюиды

conduit

трубопровод; труба

duct

труба (не с круглым поперечным

сечением)

flow (move)

поток; течение

pipe

трубопровод

pipe system

система трубопроводных линий

fitting(s)

фитинг

flow rate control device

регулятор скорости потока

restrain

удерживать

valve

клапан

fluid motion

движение флюидов

shear stress

напряжение сдвига

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