• Is it true that…:

1. hydraulic systems installed on the aircraft were to make easier the job of the pilots?

2. braking systems can be considered as the first hydraulics in the aircraft?

3. the hydraulic power can be used to drive the gun system?

4. the hydraulic power itself comes from engines?

5. aircraft hydraulic fluids are of one specification?

• Change into Active the following sentences:

1. The hydraulic actuators are controlled by valves.

2. Hydraulic power is used for other purposes.

3. Stringent care is required when handling aircraft hydraulic fluid.

• Put the verbs in brackets into the correct form:

The actuating cylinder (can, to change) ___ hydraulic power to linear or rotating motion. It has a reduction gear in it to reduce rotating motion to that amount which (to be, to need)__. Previously, systems used to control motion by (to use) ___ steel cables connected by pulleys between the controlling mechanism (such as the pedals) and the controlled surface (such as the rudder). The cables (to be, to affect) _____ by expansion rates of the cables due to temperature changes. Hydraulic systems can control motion without (to worry) ___ about the effect of temperature since it is a closed system (not open to the atmosphere) (to compare) ____ to a cable system. This means better control of the plane and less lag time between the pilot's movement to control the plane and the response by the control surface.

• Translate the text with the help of a special dictionary and learn the terms by heart:

Some Devices Operated by Hydraulic Systems in Aircraft

Primary control boosters

Retraction and extension of landing gear

Sweep back and forth of wings

Opening and closing doors and hatchways

Automatic pilot and gun turrets

Shock absorption systems and valve lifter systems

Dive, landing, speed and flap brakes

Pitch changing mechanism, spoilers on flaps

Bomb bay doors and bomb displacement gear

• The following sentences have been removed from the text. Look at the gaps in the text and decide where they fit.

1. The two chambers are called the piston rod side chamber and the bottom chamber.

2. The generation power for this system is actually the hydraulic pump, which brings a regulated flow of fluid into the cylinder tube.

3. Typically, hydraulic cylinders are used in the manufacturing and of vehicles.

4. This fluid is usually a form of oil, though other options can be used.

Hydraulic cylinders are also referred to as linear hydraulic motors. Hydraulic cylinders are a mechanism that is utilized to apply a force that is linear through a stroke that is linear. 1 __________ .

The power that hydraulic cylinders operate from comes from hydraulic fluid that has been pressurized. 2. ________. The cylinder is merely a barrel with a piston connected to a rod that stays in motion while the piston is being acted upon. The barrel is closed at the bottom and the top where the piston rod is inserted. The piston has seals and rings that slide. The inside of the cylinder is divided into two separate chambers using the piston. 3. _________ . The hydraulic pressure forces the piston to conduct linear work.

In other words, it forces the piston to move backwards or forward in a straight line, with no deviation. Hydraulic cylinders act as the motor in this particular type of system. 4. _________ . In addition to the piston rod there are mounting brackets called clevises affixed to the bottom of the cylinder that allow the cylinder to be mounted where needed.

(from http://www.hydrauliccylinders.com/)

• Read about the advantages of hydraulic systems (over other systems for aircraft use) and make the statements shorter:

• It is lighter in weight than alternate existing systems.

• It is dead beat, that is, there is an absence of sloppiness in its response to demands placed on the system.

• It is reliable; either it works or doesn't.

• It can be easily maintained.

• It is not a shock hazard; it is not much of a fire hazard.

• It can develop practically unlimited force or torque.

(from http://www.allstar.fiu.edu/aero/Hydr01.htm)

• Find grammar mistakes in the sentences of the following text:

Landing gear consists of the wheels that stick out below the fuselage so that an airplane can roll down the runway during landing and takeoff. In early aircraft, they were fixed in an open position so that they protruded at all times, even while the plane was flying and nowhere near the ground. The researchers found that reducing the drag produced by the landing gear would significantly improve the performance of the airplane in flight.

When designing an aircraft, engineers have always had to address five conflicting requirements. These are: performance, weight, cost, reliability, and maintenance.

Airplane designers explored numerous ways to retract aircraft landing gear into the fuselage. In some aircraft they were pulled straight up, usually into cowlings behind the engines, sometimes with part of the wheels protruding outside the airplane. In other cases the struts folded inward so that the wheels fit into the bottom of the fuselage horizontally, sometimes covered with a door to further reduce drag. Some of the drive mechanisms were electric, whereas others were hydraulic. The designers had to ensure that the gear deployed and locked in place. (In a landing gear the hydraulic motor can produce enough power to pull up the landing gear system without trouble even though air loads act on the system and the slip stream air is impinging against it).

Today, many low-speed private aircraft still have fixed landing gear because of cost and maintenance concerns. Some even have the streamlined "pants" coverings over their wheels. But virtually all larger and faster aircraft have completely retractable landing gear. Designing such gear presents engineers with a number of problems, particularly how to mount them on the airplane without affecting other parts of the aircraft design.

(With the help of http://www.centennialofflight.gov/essay/Evolution_of_Technology/landing_gear/)

• Translate from Russian into English:

Гидропомпа – это насос в гидросистеме самолета, создающий нужное давление, а в авиационных двигателях жидкостного охлаждения – циркуляцию охлаждающей жидкости.

Гидросистема – это замкнутая, заполненная специальной жидкостью система, состоящая из силовых цилиндров, трубопроводов с арматурой, бака для жидкости и источника давления – насоса или сжатого воздуха в баллоне, служащая для приведения в действие агрегатов и устройств. Гидросистема в самолете применяется для разнообразных целей: подъема и выпуска шасси, торможения, управления створками люков и др.

Unit 5

Text HYDRAULIC PUMPS AND CONSTANT FREQUENCY

DRIVE GENERATORS

• Have you heard about the aircraft corporation Rubin? What is it famous for? Can you guess what kind of goods does it produce?

• Translate the following expressions:

aircraft electrical power systems, alternating current sources, aircraft requirements, alternate aircraft power source, aircraft control system, aircraft engineering requirements, customer requirements functional potentialities, pressure fluctuation, sophisticated engineering construction solutions, reduced input pressure, .energy saving modes, ensured heat rejection rises, fire and explosion safety hydraulic liquids.

• Give synonyms to the following words and phrases:

to be designed, to be produced, sophisticated, to provide, to decrease, to apply, constant.

Words and phrases:

plunger pump плунжерный насос

variable переменная (величина); параметр, изменчивый

displacement смещение; сдвиг, деформация

state-of-the-art современный

reliable надежный

off-loading mechanism разгрузочный механизм

fluctuation колебание, флуктуация; пульсация, отклонение

sophisticated сложный

pressure uprating device предохранительный клапан

to bronze of sth бронзировать

to subject to sth подлежать чему-л

friction трение

electron-beam welding электронно-лучевая сварка

axial plunger осевой плунжер

shaft вал

centrifugal boosting pump центробежный насос

to facilitate облегчать, способствовать, продвигать

working capacity грузоподъемность, рабочая мощность

drive generator задающий генератор

alternating current переменный ток

Aircraft corporation «Rubin» has designed and is producing now several generations of plunger pumps with constant and variable supply providing pressure of 80, 150, 210, 280 kgf/sm2 with a normalized operating displacement from 2 to 60 sm3/r which are completely providing aircraft engineering requirements.

All pump characteristics are corresponding to the state-of-the-art international standards and provide highly reliable operating in a wide range of environment.

On customer requirements functional potentialities should be improved. We can build-in pump off-loading mechanism, pressure uprating device, boosting pumps and other construction elements.

Our pumps provide a low level of pressure fluctuation due to sophisticated engineering construction solutions.

Pumps with displacement from 2 to 60 sm3/r and higher, with minimal pressure fluctuation.

Sophisticated technologies used in hydraulic units construction bronzing of surfaces subject to friction, electron-beam welding of plungers, optimal friction couple matching and so on.

Pump is applied in hydraulic systems developed for airplanes IL96-300 and TU204 and their modifications operating with fire and blow safe hydraulic liquids on base of organophosphorus ethers.

Pump includes the rotating cylinder block, axial plunger disposal, the front distribution of operational liquid, and liquid regulator.

The pump scheme has a special device to decrease high frequency pulsation of delivery pressure.

There was used an original engineering solution of the delivery control device that provides a stable regulation through the whole operational range of pressure, stable pump shaft rotation and temperature.

A cenrifugal boosting pump is installed in the plunger pump body, and provides uncavitation functioning of plunger pump under the reduced input pressure.

Electrical hydraulic off-loading device receiving an electrical signal can switch off the plunger pump from the hydraulic system in the following cases: to facilitate engine starting; to operate in energy saving modes; to protect the pump and the hydraulic system during emergency situation.

The pump is supplied by a special device to provide the working capacity when the pressure in the outlet pipes with an ensured heat rejection rises.

Applied at hydraulic systems of different modifications of aircrafts IL96-300 and TU204 which use fire and explosion safety hydraulic liquids with organophosphorus esters.

Drive generators are applied in aircraft electrical power systems as the alternating current sources with stable frequency. That permits to decrease sufficiently the mass of the systems and the aircraft in general.

Aircraft corporation «Rubin» has designed and is manufacturing several generations of hydraulic drive generators of different power that satisfy the aircraft requirements.

DRIVE GENERATOR GP25 is designed to supply an aircraft electrical system with AC electrical power with stable frequency.

DRIVE GENERATOR GP27 is designed and produced by AC «Rubin» as an alternate aircraft power source used in emergency. It is designed to supply aircraft control system users in case of failure (deenergization) general power sources and produces DC 27 V, rated output power 0.3 – 2.7 KW.

(From the official site http://www.ak-rubin.ru/eng/hydraulic.html)

• According to the text are these sentences true or false?

1. Aircraft corporation «Rubin» produces jet planes and small private

planes.

2. Aircraft corporation «Rubin» has designed and is manufacturing several generations of hydraulic drive generators of different power.

3. The pumps manufactured by AC «Rubin» provide a low level of pressure fluctuation.

4. A lot of original engineering solutions and sophisticated technologies are used by the designers of the corporation.

5. The pumps manufactured by AC «Rubin» are used in hydraulic systems of different modifications of aircrafts IL96-300 and TU204.

• Look through the text and make a list of all the advantages of the pumps and the generators produced by AC «Rubin».

• Ask you partner 3 questions (general, special, alternative) about the text .

• Make the following sentences passive:

1. Aircraft corporation «Rubin» has designed and is producing now several generations of plunger pumps.

2. All pump characteristics are corresponding to the state-of-the-art international standards.

3. Pump includes the rotating cylinder block, axial plunger disposal, the front distribution of operational liquid, and liquid regulator.

4. The generator produces DC 27 V, rated output power 0.3 – 2.7 KW.

• Put the right forms of the verbs in the blanks:

Hydraulic pumps (to supply) fluid to the components in the system. Pumps have a power density about ten times greater than an electric motor (by volume). They (to be/to power) by an electric motor or an engine, connected through gears, belts, or a flexible elastomeric coupling to reduce vibration. Common types of hydraulic pumps to hydraulic machinery applications (to be): gear pumps, vane pumps, axial piston pumps, radial piston pumps. Piston pumps (to be) more expensive than gear or vane pumps, but (to provide) longer life operating at higher pressure, with difficult fluids and longer continuous duty cycles.

(from http://en.wikipedia.org/wiki/Hydraulic_machinery)

• Complete the sentences with a suitable relative pronoun:

1. Gear pumps are the pumps … are less efficient, because they are mainly suitable for pressures below 20 MPa.

2. Axial piston pumps are the pumps … aim is to vary output flow for automatic control of pressure.

3. Hydrostatic transmissions for earth moving machines, such as for tractor loaders, are often equipped with a separate 'Inch pedal' … is used to temporarily increase the diesel engine rpm.

4. Hydraulic machinery are machines and tools … use fluid power to do work.

5. A seal allows part of the spool to protrude outside the housing, … it is accessible to the actuator.

6. Check valves are one-way valve … can be opened (for both directions) by a foreign pressure signal.

• Find the mistakes. Two of the sentences below are correct. Tick them. Correct the mistakes in other sentences:

1. Directional control valves have usually designed to be stackable, with one valve for each hydraulic cylinder, and one fluid input supplying all the valves in the stack.

2. Pressure relief valves are using in several places in hydraulic machinery; on the return circuit to maintain a small amount of pressure for brakes, pilot lines, etc...

3. Sequence valves control the sequence of hydraulic circuits; to insure that one hydraulic cylinder is fully extended before another starts its stroke, for example.

4. Check valves are one-way valves, is allowing an accumulator to charge and maintain its pressure after the machine is turned off, for example.

5. Counterbalance valves are in fact a special type of pilot controlled check valves.

6. Cartridge valves generally screw into a valve block and are electrically are controlled to provide logic and automated functions.

7. Hydraulic fuses are in-line safety devices designed to automatically seal off a hydraulic line if pressure becomes too low.

8. Auxiliary valves are usually custom valves designed for the particular machine, and may consisted of a metal block with ports and channels drilled.

• Unjumble the words (connected with hydraulics) in the following sentences:

1. For the hydraulic fluid to do work, it must flow to the utcataor and or motors.

2. Multiple valves can be connected in a parallel arrangement and system spuresre is equal for all valves.

3. New uhraldiyc functions can easily be added and the system is quick in response.

4. Load-sensing systems generates less power losses as the pump can reduce both flow and pressure to match the load mrenuieqtres.

5. An interesting aspect of hydraulic systems is the ability to apply force caltiptiomliun.

6. Recent technical achievements for the converter stmirnasiosns have improved the efficiency and developments in the software.

• Translate from Russian into English:

Привод или гидравлический мотор является основным компонентом системы, в котором механическая работа выполняется с помощью движения гидравлической жидкости. Простейшими двигателями являются линейные приводы, в которых жидкость оказывает давление на поршень цилиндра.

Клапаны используются в гидравлических контурах для регулировки рабочего давления, направление потока и расход.

Другими важными компонентами являются резервуар (или бак) и фильтры.

• Make up a dialogue where A – is a customer and B – is an AC «Rubin» marketing director. Discuss the possibility of buying pumps or generators.

There is an example of an order letter below. Read it and write to AC «Rubin» and order pumps or generators.

PURCHASE ORDER

[Date]

[NAME, COMPANY AND ADDRESS, ex.

ZIP POST CODE]

Dear [NAME],

Please accept this purchase order for the following:

QUANTITY PRODUCT UNIT PRICE TOTAL

[LIST PRODUCTS AND PRICES]

We require shipment by [DATE, ex. June 20, 1998] to:

[ADDRESS]

Please refer to this order as “purchase order #[PURCHASE NUMBER]”. If this order cannot be processed as requested, please contact me at XXX-XXXX at your earliest convenience.

Sincerely,

[YOUR NAME]

(from http://isampleletter.com/)

Unit 6

Text Hydraulic power units

• What do you know about space shuttles? Share your knowledge with your groupmates. Have you got any idea about the semblance between rocket hydraulics and aircraft hydraulics?

Words and phrases:

solid rocket booster ускоритель ракеты на твердом топливе

stage ступень (ракеты)

thrust реактивная сила

propulsion движущая сила, импульс, толчок, тяга

hydraulic fluid manifold assembly система труб, заполненная рабочей жидкостью

aft end кормовая часть

aft skirt полый цилиндр, юбка

tilt actuator механизм наклона кузова в кривой

servoactuator сервопривод; серводвигатель

attach ring примыкающее кольцо

fuel isolation valve запорный топливный клапан

startup пуск, запуск; ввод в эксплуатацию

startup bypass line перепускное устройство при запуске

fuel pump outlet pressure давление на выходе топливного насоса

lube oil pump насос системы смазки

exhaust duct сопло

to assume допускать, предполагать

to switch включать

high pressure relief valve предохранительный клапан

• Guess the meanings of these words by their prefixes. Then look through the text and find these words in the sentences. Do they have the same meanings?

overpressure, overboard external, self-contained, to decompose, reusable.

• Do you know the meanings of these words? What are they? Find these words in the text and compare the meanings. Do they differ?

rock, skirt, power, tank, nozzle, chamber, relief

• Translate into Russian

most powerful single-chamber liquid fueled rocket engine, solid-fuel rocket motors, aft integrated electronic assemblies, the aft external tank attach rings, auxiliary power unit turbine assembly, high pressure relief valve, overpressure protection.

The Space Shuttle Solid Rocket Boosters (SRBs) are the pair of large solid rockets used by the Space Shuttle during the first two minutes of powered flight. 1._____ The SRBs are the largest solid-fuel rocket motors ever flown, and the first to be used for primary propulsion on human spaceflight missions.

There are two self-contained, independent Hydraulic Power Units (HPUs) on each SRB. 2. _____. The APUs are fueled by hydrazine and generate mechanical shaft power to a hydraulic pump that produces hydraulic pressure for the SRB hydraulic system. The two separate HPUs and two hydraulic systems are located on the aft end of each SRB between the SRB nozzle and aft skirt. The HPU components are mounted on the aft skirt between the rock and tilt actuators. The two independent hydraulic systems are connected to the rock and tilt servoactuators.

The HPU controller electronics are located in the SRB aft integrated electronic assemblies on the aft external tank attach rings.

The HPUs and their fuel systems are isolated from each other. The fuel tank is pressurized with gaseous nitrogen at 2.8 MPa, which provides the force to expel (positive expulsion) the fuel from the tank to the fuel distribution line, maintaining a positive fuel supply to the APU throughout its operation.

The fuel isolation valve is opened at APU startup to allow fuel to flow to the APU fuel pump and control valves and then to the gas generator. 3. ______. It feeds the hot gas exhaust product to the APU two-stage gas turbine. Fuel flows primarily through the startup bypass line until the APU speed is such that the fuel pump outlet pressure is greater than the bypass line's. Then all the fuel is supplied to the fuel pump.

The APU turbine assembly provides mechanical power to the APU gearbox. The gearbox drives the APU fuel pump, hydraulic pump and lube oil pump. 4. ______. The turbine exhaust of each APU flows over the exterior of the gas generator, cooling it, and is then directed overboard through an exhaust duct.

When the APU speed reaches 100%, the APU primary control valve closes, and the APU speed is controlled by the APU controller electronics. If the primary control valve logic fails to the open state, the secondary control valve assumes control of the APU at 112% speed.

Each HPU on an SRB is connected to both servoactuators on that SRB. One HPU serves as the primary hydraulic source for the servoactuator, and the other HPU serves as the secondary hydraulics for the servoactuator. Each servoactuator has a switching valve that allows the secondary hydraulics to power the actuator if the primary hydraulic pressure drops below 14 MPa. 5. _____. When the valve is closed, a signal is sent to the APU controller that inhibits the 100% APU speed control logic and enables the 112% APU speed control logic. The 100-percent APU speed enables one APU/HPU to supply sufficient operating hydraulic pressure to both servoactuators of that SRB.

The hydraulic pump speed is 3,600 rpm and supplies hydraulic pressure of 21 MPa, plus or minus 345 kPa. A high pressure relief valve provides overpressure protection to the hydraulic system and relieves at 26 MPa.

(from http://en.wikipedia.org/wiki/Space_Shuttle_Solid_Rocket_Booster)

• The following sentences have been removed from the text. Look through the text and decide which sentence should be in the gap.

1. Each SRB produces 1.8 times more liftoff thrust than one F-1 engine – the all-time most powerful single-chamber liquid fueled rocket engine ever flown.

2. Each HPU consists of an auxiliary power unit (APU), fuel supply module, hydraulic pump, hydraulic reservoir and hydraulic fluid manifold assembly.

3. The gas generator's catalytic action decomposes the fuel and creates a hot gas.

4. The APU lube oil pump lubricates the gearbox.

5. A switch contact on the switching valve will close when the valve is in the secondary position.

• Read the text quickly again and answer the following questions about the text in your own words:

1. How can you describe the space shuttle solid rocket boosters?

2. How many hydraulic power units are there on a solid rocket booster?

3. What does a hydraulic power unit consist of?

4. Where are the HPU components placed?

5. What happens when the fuel decomposes?

6. What drives the APU fuel pump?

7. What are the functions of each HPU?

8. What does a servoactuator do?

• Comment the underlined grammar phenomena in the following sentences:

1. The SRBs are the largest solid-fuel rocket motors ever flown, and the first to be used for primary propulsion on human spaceflight missions.

2. The turbine exhaust of each APU flows over the exterior of the gas generator, cooling it, and is then directed overboard through an exhaust duct.

• Compose the sentences using the following words:

1. Hydraulic machinery are machines and tools which use fluid power to do work.

2. High pressure hydraulic fluid is transmitted throughout the machine to various hydraulic motors and hydraulic cylinders.

3. The control valve is one of the most expensive and sensitive parts of a hydraulic circuit.

4. Sequence valves control the sequence of hydraulic circuits.

5. They are available in many configurations.

• There is one unnecessary word in each sentence below. Cross it out:

1. SRBs they are located on either side of the orange external propellant tank.

2. During are launch they provide 83% of its liftoff thrust.

3. Each SRB has have two hydraulic gimbal servoactuators: one for rock and one for tilt.

4. The spent SRBs are recovered from the ocean, refurbished, reloaded with propellant, and reused for several the missions.

5. Each SRB servoactuator consists of four independent, two-stage servovalves that receive which signals from the drivers.

6. Failure monitors are provided for each is channel to indicate which channel has been bypassed.

7. Each actuator ram is equipped with transducers are for position feedback to the thrust vector control system.

• Put the verbs in brackets into the correct form:

1. To keep up pressure on the low pressure side, the circuits (to have)a charge pump (a small gearpump) that supplies cooled and filtered oil to the low pressure side.

2. Closed-loop circuits (to use) for hydrostatic transmissions in mobile applications.

3. The pump (can/to utilize) for any other hydraulic function and cooling can be a problem due to the limited exchange of oil flow.

4. Closed loop systems generally have a 'flush-valve' (to assemble) in the hydraulic motor in order to exchange more flow than the basic leakage flow from the pump and the motor.

5. The leakage (to flow) as well as the extra flush flow (must/to supply) by the charge pump.

6. Closed loop systems in mobile equipment (to use) for the transmission as an alternative to mechanical and hydrodynamic (converter) transmissions.

• Translate from Russian into English:

Для самолетов, ракет и космических летательных аппаратов требуются специальные высокоэнергетические топлива. Существуют два основных типа двигателей для летательных аппаратов, используемых в авиации и космонавтике.

Топливо для воздушно-реактивных двигателей, в которых в качестве окислителя используется кислород атмосферного воздуха, должно иметь высокую удельную теплоту сгорания. Кроме того, такое топливо должно быть термически устойчивым. Для достижения наивысших технических показателей летательного аппарата такое топливо должно иметь также высокую плотность.

Таким образом, в авиационной технике проблема состоит в нахождении топлива, которое характеризуется большой плотностью и высокой удельной теплотой сгорания. В настоящее время большинство реактивных двигателей работает на керосине или на бензине в качестве топлива. Однако ведутся исследования смесей специальных углеводородных соединений, которые обладали бы более высокой плотностью. Значительное внимание уделяется также поиску других видов топлив.

(with the help of http://www.bigpi.biysk.ru/encicl/articles/11/1001193/1001193A.htm)

• Read the beginning of the internet report. Imagine that you are a journalist of some popular newspaper. The rating of your newspaper may depend on your would-be report. Write the one of your own. Think carefully of the headline, make it attractive. Try to give your report a shade of sensation.

Upgraded Ariane 5 solid rocket booster test fired

BY STEPHEN CLARK

SPACEFLIGHT NOW

November 22, 2001

A test firing of a full-sized Ariane 5 solid rocket booster was performed Tuesday, marking an important step in Europe's plans to increase the rocket's payload capacity and to lower production expenses.

The exhaust cloud billows into the sky as the solid rocket motor is test fired.

The firing was part of the Ariane 5 Research and Technology Accompaniment, or ARTA, program. ARTA is designed to confirm that the Ariane 5 remains reliable, to qualify performance improvements, and to oversee and validate changes in the system resulting from obsolescence.

(from http://spaceflightnow.com/news/n0111/22a5srbtest/)