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TERM PAPER

On

Hydraulics

Submitted to

AMITY SCHOOL OF ENGINEERING

Guided By: Submitted By:

Dr. Siddheshwar Chopra Deepansh Pandey

M.Sc., Ph.D (Physics) A12405212013

Assistant Professor (Physics) Roll no. 2013

ASET ASE ( CSE )

Amity University, Uttar Pradesh

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Acknowledgement

I am fortunate enough to study in Amity university, Noida under the guidance of Prof.

Kesar Singh who infused me with Great confidence to take Summer internship in one of

the biggest names among multi-activity, multi-technology, multi-location conglomerate

that has a global footprint.

Now that the Summer project is done, there is finally time to reflect on the project. No

project is ever growing full blown from the researcher’s head. It has the hands to help it

along the way.

I am particularly indebted to my mentor, Dr. Siddheshwar Chopra M.Sc., Ph.D

(Physics) whose help, brilliant creativity, and enthusiasm have guided this report from

its conception to completion. I also thank him for his inspired support from the

beginning of the project, expert feedbacks and advice. I am greatly blessed and humbled

for my experience with him whose pioneering vision as the guiding force behind the

efficiency of my internship project.

Deepansh Pandey

A12405212013

ASE (CSE)

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Certificate

This is to certify that Mr Deepansh Pandey , student of B. Tech. In Computer

Science and engineering has carried out the work presented in the project of the

Term paper entitle "Hydraulics" as a part of First year program of Bachelor of

Technology in Physics from Amity School of Engineering, Amity University,

Noida, Uttar Pradesh under my supervision.

Dr. Siddheshwar Chopra

M.Sc., Ph.D (Physics)

Assistant Professor (Physics)

ASE, Noida

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Contents

I. Acknowledgement.............................................................................................. 02

II. Certificate........................................................................................................... 03

III. Contents.............................................................................................................. 04

IV. Summary............................................................................................................. 05

V. Introduction........................................................................................................ 06

VI. Basic Hydraulics.................................................................................................07

1. Basic terms............................................................................................. 07

2. Energy equation..................................................................................... 08

3. Orifices and weirs.................................................................................. 09

4. Frictional loss......................................................................................... 09

VII. Fluids.................................................................................................................. 10

1. Characteristics of hydraulic fluids.......................................................... 10

2. Observation and methodologies............................................................. 11

3. Types of hydraulics fluids...................................................................... 12

VIII. Application of hydraulics fluids......................................................................... 13

1. Hydraulics Braking................................................................................. 14

2. Hydraulic Press....................................................................................... 15

3. Hydraulic Lift......................................................................................... 16

4. Hydraulic Cranes.................................................................................... 17

IX. International Work in hydraulics........................................................................ 19

X. Result.................................................................................................................. 20

XI. My contribution.................................................................................................. 21

XII. References.......................................................................................................... 22

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Summary

The word “hydraulics” generally refers to power produced by moving liquids. Modern

hydraulics are defined as the use of confined liquid to transmit power, multiply force, or

produce motion. The aim of the project is to study the basics of hydraulics and the fluids

used in hydraulic , to understand the applications of hydraulics in today’s world.

As with any technical topic, a full understanding cannot come without first becoming

familiar with basic terminology and governing principles. Starting with the basics of

hydraulics including the energy principle, orifices and weirs, friction losses, pressure

flow, Now coming to the FLUIDS, Hydraulic fluids have the primary purpose of

transferring potential or kinetic energy (pressure and movements), creates volume flow

between the pump and hydrostatic motor, and reduce the wear of parts that rub against

each other. In addition, they protect the system from corrosion and help carry away the

heat produced during energy transformation. APPLICATION OF HYDRAULICS,

Hydraulics is fluid power technology dealing with the ways of using pressurized liquid

for doing work. Hydraulic systems are commonly used where mechanisms require large

forces and precise control. Liquid is ideal for transferring a force from the control

mechanism to the mechanism doing the work. Because liquid does not compress, it

transfers all the force and enables precise movement.

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Introduction

The word “hydraulics” generally refers to power produced by moving liquids. Modern

hydraulics are defined as the use of confined liquid to transmit power, multiply force, or

produce motion. Though hydraulic power in the form of water wheels and other simple

devices has been in use for centuries, the principles of hydraulics weren’t formulated in

scientific law until the 17th century. It was then that French philosopher Blaise Pascal

discovered that liquids cannot be compressed. He discovered a law which states:

Pressure applied to a confined fluid is transmitted in all directions with equal force on

equal areas.

Hydraulic fluids, also called hydraulic liquids, are the medium by which power is

transferred in hydraulic machinery. Common hydraulic fluids are based on mineral oil

or water. Examples of equipment that might use hydraulic fluids include excavators and

backhoes, hydraulic brakes, power steering systems, transmissions, garbage trucks and

aircraft flight control systems and industrial machinery.

Hydraulics are used in many machines that we see in our daily lives. Some of its uses

are:

HYDRAULIC BRAKES

HYDRAULIC PRESS

HYDRAULIC LIFT

HYDRAULIC CRANES

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Basic Hydraulics

Basic Terms

The basic concepts discussed in the following pages lay the foundation for the more

complex analyses present further in the project .

Flow conveyance

Water travels downhill from points of higher energy to points of lower energy reaches a

point of equilibrium, such as an ocean. Hydraulic concepts can be applied equally to

both man-made structures and natural features.

Area, Wetted Perimeter, and Hydraulic Radius

The term area refers to the cross-sectional area of flow within a channel.

A section’s wetted perimeter is defined as the portion of the channel in contact with the

flowing fluid

The hydraulic radius of a section is not a directly measurable characteristic, but it is

used frequently during calculations. It is defined as the area divided by the wetted

perimeter, and therefore has units of length.

Velocity

The velocity of a section is not constant throughout the cross-sectional area. Instead, it

varies with location. The velocity is zero where the fluid is in contact with the conduit

wall. The variation of flow velocity within a cross-section complicates the hydraulic

analysis, so the engineer usually simplifies the situation by looking at the average

(mean) velocity of the section for analysis purposes. This average velocity is defined as

the total flow rate divided by the cross-sectional area, and is in units of length per time.

Steady Flow

Speaking in terms of flow, the word steady indicates that a constant flow rate is

assumed throughout an analysis. In other words, the flow velocity does not change with

respect to time at a given location. For most hydraulic calculations, this assumption is

reasonable. When analyzing tributary and river networks, storm sewers, and other

collection systems in which it is desirable to vary the flow rate at different locations

throughout the system, the network can often be broken into segments that can be

analyzed separately under steady flow conditions.

Laminar Flow, Turbulent Flow, and Reynolds Number

Laminar flow is characterized by smooth, predictable streamlines (the paths of single

fluid particles). An example of this type of flow is maple syrup being poured.

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In turbulent flow, the streamlines are erratic and unpredictable. Turbulent flow is

characterized by the formation of eddies within the flow, resulting in continuous mixing

throughout the section.

To classify flow as either turbulent or laminar, an index called the Reynolds number is

used. It is computed as follows:

Re= 4VR/v

Where, Re = Reynolds number (unitless)

V = average velocity

R = hydraulic radius

v = kinematic viscosity

If the Reynolds number is below 2,000, the flow is generally laminar. For flow in closed

conduits, if the Reynolds number is above 4,000, the flow is generally turbulent.

Between 2,000 and 4,000, the flow may be either laminar or turbulent, depending on

how insulated the flow is from outside disturbances. In open channels, laminar flow

occurs when the Reynolds number is less than 500 and turbulent flow occurs when it is

above 2,000. Between 500 and 2,000, the flow is transitional.

The Energy Principle

The first law of thermodynamics states that for any given system, the change in energy

(ΔE) is equal to the difference between the heat transferred to the system (Q) and the

work done by the system on its surroundings (W) during a given time interval.

In hydraulic applications, energy values are often converted into units of energy per unit

weight, resulting in units of length. Using these length equivalents gives engineers a

better “feel” for the resulting behavior of the system. When using these length

equivalents, the engineer is expressing the energy of the system in terms of “head.” The

energy at any point within a hydraulic system is often expressed in three parts, as shown

Pressure head

Elevation head

Velocity head

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The Energy Equation

In addition to pressure head, elevation head, and velocity head, energy may be added to

a system by a pump (for example), and removed from the system by friction or other

disturbances. These changes in energy are referred to as head gains and head losses,

respectively. Because energy is conserved, the energy across any two points in the

system must balance. This concept is demonstrated by the energy equation.

Orifices and weirs

The energy equation serves as the foundation for calculating the flow through and over

Hydraulic structures based on the size of the opening associated with the structure and

the difference in energy on either side of it. The flow exiting the structure can be

calculated by solving the energy equation for velocity, V2, and multiplying the resulting

formula by the flow area and a coefficient to account for different hydraulic and

physical variables.

These variables include: head loss, the shape and nature of the opening, the contraction

of the flow after it leaves the structure, and countless indefinable variables that are

difficult to measure but produce quantifiable effects.

Two common devices for which equations are derived in this manner are weirs and

Orifices. They are important not only because of their widespread usage in the industry,

But also because the equations that describe them serve as the foundation for

Mathematical descriptions of more complicated hydraulic devices such as drainage

inlets and culverts.

Orifices-

Orifices are regularly shaped, submerged openings through which flow is propelled by

The difference in energy between the upstream and downstream sides of the opening.

The stream of flow expelled from the orifice is called the gate. When the jet exits the

orifice, adverse velocity components cause it to contract to a point after which the flow

area remains relatively constant and the flow lines become parallel . This point

is called the vena contracta.

Weirs

Weirs are notches or gaps over which fluid flows. The lowest point of structure surface

or edge over which water flows is called the crest, whereas the stream of water that exits

Over the weir is called the nappe. Depending on the weir design, flow may contract as it

exits over the top of the weir, and, as with orifices, the point of maximum contraction is

called the vena contracta.

Frictional Loss

Friction loss is the loss of energy or “head” that occurs in pipe flow due to viscous

effects generated by the surface of the pipe. Friction Loss is considered as a "major

loss" and it is not to be confused with “minor loss” which includes energy lost due to

obstructions. For calculation of frictional loss we have

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Chézy’s (Kutter’s) Equation

The Chézy equation, in conjunction with Kutter’s equation, is widely used in sanitary

sewer design and analysis. The roughness component, C, is a function of the hydraulic

radius, friction slope, and lining material of the channel. The Chézy equation is

𝑉 = 𝐶√𝑅𝑆 where V = mean velocity (m/s, ft/s)

C = roughness coefficient

R = hydraulic radius (m, ft)

S = friction slope (m/m, ft/ft)

Fluids

Characteristics of Hydraulic Fluids

Hydraulic fluids have the primary purpose of transferring potential or kinetic energy

(pressure and movements), creates volume flow between the pump and hydrostatic

motor, and reduce the wear of parts that rub against each other. In addition, they protect

the system from corrosion and help carry away the heat produced during energy

transformation.

The necessary characteristics of hydraulic fluids are as follows:

They should be volume stable means they should have adequate capacity to separate

air.

They should have the corrosion protection capacity.

They should be non-aggressive toward customary materials and rust protection

additives.

They should wear protection capacity for all other wear reducing additives.

There should not be a slight change in their physical and chemical properties while

usage.

Observation and methodologies related to the Hydraulic Fluid

Hydraulic fluid has to perform the following tasks:

• Energy transmission

• Lubrication

• Heat removal

When choosing a hydraulic fluid the following features are most important for

consideration:

• Viscosity

• Viscosity Index (VI) and/or Viscosity Grade (VG) viscosity at 40 °C [104 °F].

• Pour point

Viscosity

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A hydraulic fluid has a low viscosity when it is thin and a high viscosity when it is

thick. The viscosity changes with the temperature.

• If the temperature increases, the viscosity is reduced.

• If the temperature decreases, viscosity is increased.

Hydraulic units work under extreme temperature changes, especially in heavy duty

vehicles. The viscosity range of the hydraulic fluid is extremely important. The

hydraulic fluid must be thin enough to flow through the filter, inlet and return pipes

without too much resistance. On the other hand, the hydraulic fluid must not be too

thin, in order to avoid wear due to lack of lubrication and to keep internal leakage

within limits. In the hydraulic business typically the kinematic viscosity ν in mm2/s is

used for calculations, mainly for calculating the pressure drop in the connecting hoses

and pipes. Dynamic viscosity is used for calculating the lubricating film.

Viscosity index (VI)

The viscosity index is a calculated number, which describes the viscosity change of a

mineral oil based or a synthetic fluid versus temperature

• A high viscosity index means a small viscosity change when the temperature changes

• A low index means a large viscosity change when the temperature changes.

Most hydraulic fluids have a VI value of 90 - 110.

Hydraulic fluids with a VI larger than 110, e.g. between 130 -200, are not as sensitive to

temperature change. These hydraulic fluids distinguish themselves by starting up well

and having minimal loss in performance at low temperatures. At high temperatures a

sufficient sealing effectiveness and protection against wear is achieved by using

hydraulic fluids with high viscosity index. The high durability of a hydraulic fluid with

a high viscosity index avoids damage and machine breakdown, lowers the operating

cost and increases the life of hydrostatic transmissions and units.

Pour point

The pour point defines the temperature when the fluids stops to flow. Start up

temperature is recommended to be approximately 15 °C above hydraulic fluid pour

point.

Density

The density has to be specified by the manufacturer of the hydraulic fluid. Using

hydraulic fluid with a high density requires the sufficient diameter of the suction line

and/or elevated tank to provide positive inlet pressure

Sealing compatibility

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In general NBR (Nitrile) or FPM (Fluorocarbon, Viton) is used as sealing material for

static and dynamic seals. For most hydraulic fluids both seal materials are suitable, but

for some hydraulic fluids only one kind is preferred.

Bulk modulus/Compressibility

While fluids are usually considered incompressible, the pressures that can occur in

hydrostatic systems are of a magnitude that fluid compressibility can be significant. In

applications that experience system pressure fluctuations resulting in random high

pressure rise rates, consideration must be given to fluid compressibility when sizing a

charge pump to ensure adequate charge pressure. The amount that a specific fluid

compress for a given pressure increase relates to a fluid property known as the bulk

modulus. The bulk modulus is a measure of a fluids resistance to being compressed. It

depends on pressure and temperature. The air content is important as well especially

below 50-100 bar . The higher the air content the more spongy the system. For a given

pressure increase and fluid volume, a fluid with a large bulk modulus will experience a

smaller reduction in volume than a fluid with a low bulk modulus.

Some Other terms related to fluid hydraulics

Cleanliness level

The cleanliness level of a hydraulic fluid is determined by counting the number and size

of particles in the fluid. The number of particles is defined as a cleanliness level.

Air content

Air in a system is also regarded as a contaminant. Air increases the compressibility of

the fluid, resulting in a “spongy” system that is less responsive. Also air creates a loss of

transmitted power, higher operating temperatures, increased noise levels, and loss of

lubricity.

Types of hydraulic Fluids

There are many types of hydraulic fluids, of which the most common would be mineral

oil, polyaphaolefin and organophosphate ester. Others are based on glycol esters and

ethers, castor oil, or silicon.

Biodegradable hydraulic Fluid

Brake Fluid

Fire resistant hydraulic fluids

Water glycol fluids.

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Application of Hydraulics Overview

Hydraulics is fluid power technology dealing with the ways of using pressurized liquid

for doing work. Hydraulic systems are commonly used where mechanisms require large

forces and precise control. Liquid is ideal for transferring a force from the control

mechanism to the mechanism doing the work. Because liquid does not compress, it

transfers all the force and enables precise movement.

A Simple hydraulic system consisting of two pistons and an oil-filled pipe connecting

them.

Two pistons fit into two glass cylinders filled with oil and connected to one another

with an oil-filled pipe. If we apply a downward force to one piston (the left one in this

drawing), then the force is transmitted to the second piston through the oil in the pipe.

Since oil is incompressible, the efficiency is very good -- almost all of the applied force

appears at the second piston. The great thing about hydraulic systems is that the pipe

connecting the two cylinders can be any length and shape, allowing it to snake through

all sorts of things separating the two pistons.

Hydraulic multiplication-The piston on the right has a surface area nine times greater

than the piston on the left. When force is applied to the left piston, it will move nine

units for every one unit that the right piston moves, and the force is multiplied by nine

on the right-hand piston.

Fig. 1

To determine the multiplication factor, assume that the piston on the left is 2 inches in

diameter (1-inch radius), and while the piston on the right is 6 inches in diameter (3-

inch radius). The area of the two pistons is Pi * r2. The area of the left piston is

therefore 3.14, while the area of the piston on the right is 28.26. The piston on the right

is 9 times larger than the piston on the left. What that means is that any force applied to

the left-hand piston will appear 9 times greater on the right-hand piston. So if we apply

a 100-pound downward force to the left piston, a 900-pound upward force will appear

on the right.

The only catch is that we will have to depress the left piston 9 inches to raise the right

piston 1 inch.

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Fig. 2

Hydraulics is used in many machines that we see in our daily lives. Some of its uses are:

HYDRAULIC BRAKES

HYDRAULIC PRESS

HYDRAULIC LIFT

HYDRAULIC CRANES

HYDRAULIC BRAKING

The brakes in our cars are a good example of a basic piston-driven hydraulic system.

When we depress the brake pedal in your car, it is pushing on the piston in the brake's

master cylinder. Hydraulic braking constituted a significant advance in comfort and

safety.

Four slave pistons, one at each wheel, actuate to press the brake pads against the brake

rotor to stop the car. Actually, in almost all cars on the road today two master cylinders

are driving two slave cylinders each. That way if one of the master cylinders has a

problem or springs a leak, you can still stop the car.

HOW DOES IT WORK?

The heart of the system is the master cylinder. It is this cylinder which compresses the

brake fluid when the driver presses on the pedal. It operates similarly to a syringe:

compression is obtained by a moving piston. As these parts wear down, their thickness

diminishes. They have to be pushed “further and further” during braking. Again, as it is

pistons which command this movement, this means that the quantity of brake fluid

contained increases gradually as the wear on the pads or linings increases. Without an

adjustment system, the driver has to push the brake pedal further and further to

compensate for this wear in order to brake effectively. The end of the master cylinder,

where the piston lies when the brake pedal is fully released, includes a light. It is

connected to a small tank of brake fluid. Hence, when the pedal is fully released, the

piston gives off light and, if necessary, the braking circuit automatically tops up the

fluid. In order to be effective and above all to ensure proper stability of the rear

suspension, braking must be distributed unevenly between the car’s front and rear

wheels. A pressure distributor follows the

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Fig. 3

master cylinder and adjusts the pressure applied on each suspension. A set of rigid

pipes and hoses carry the braking fluid to the wheels.

HYDRAULIC PRESS

The concept of the hydraulic press is based on Pascal's theory, which states that when

pressure is applied on fluids in an enclosed system, the pressure throughout the system

always remains constant. In simple words, a hydraulic press is a machine that makes use

of the pressure exerted on the fluids to crush something.

Joseph Bramah invented the hydraulic press, hence it is also known as the Bramah

Press.

How the Hydraulic Press works?

A hydraulic press consists of basic components used in a hydraulic system that includes

the cylinder, pistons, the hydraulic pipes, etc. The working of this press is very simple.

The system comprises of two cylinders, the fluid (usually oil) is poured in the cylinder

having a small diameter. This cylinder is known as the slave cylinder.The piston in this

cylinder is pushed so that it compresses the fluid in it that flows through a pipe into the

larger cylinder. The larger cylinder is known as the master cylinder. The pressure is

exerted on the larger cylinder and the piston in the master cylinder pushes the fluid back

to the original cylinder. The force applied on the fluids by the smaller cylinder results in

a larger force when pushed in the master cylinder.

Uses of a Hydraulic Press-

A hydraulic press is used for almost all industrial purposes. But basically it is used for

transforming metallic objects into sheets of metal. In other industries, it is used for the

thinning of glass, making powders in case of the cosmetic industry and for forming the

tablets for medical use and for car crashing.

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Fig.3

HYDRAULIC LIFT

One of the most important equipment used in transporting goods and people is the

hydraulic lift. By the way of hydraulics, such lifts are able to carry heavy loads with

great ease, and lift it vertically. Hydraulic lifts come in the form of passenger lift,

service lifts A hydraulic lift typically uses hydraulic cylinders to either raise or lower

platforms for work, or other lifting devices.

Hydraulic lifts are ideally used for support, as well as lift and move heavy to very

heavy, and large objects; at the same time providing a safe environment that is

ergonomically useful. While hydraulic lifts are mainly used for loading, and positioning

work objects, at times this can also use for transporting.

Working of Hydraulic Lift-

A cylinder is connected to a fluid-pumping system (typically, hydraulic systems like

this use oil, but other incompressible fluids would also work). The hydraulic system has

three parts:

o A tank (the fluid reservoir)

o A pump, powered by an electric motor

o A valve between the cylinder and the reservoir

The pump forces fluid from the tank into a pipe leading to the cylinder. When the valve

is opened, the pressurized fluid will take the path of least resistance and return to the

fluid reservoir. But when the valve is closed, the pressurized fluid has nowhere to go

except into the cylinder. As the fluid collects in the cylinder, it pushes the piston up,

lifting the elevator car. When the car approaches the correct floor, the control system

sends a signal to the electric motor to gradually shut off the pump. With the pump off,

there is no more fluid flowing into the cylinder, but the fluid that is already in the

cylinder cannot escape (it can't flow backward through the pump, and the valve is still

closed).

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Fig. 4

The piston rests on the fluid, and the car stays where it is.To lower the car, the elevator

control system sends a signal to the valve. The valve is operated electrically by a basic

solenoid switch sends a signal to the valve. The valve is operated electrically by a basic

solenoid switch. When the solenoid opens the valve, the fluid that has collected in the

cylinder can flow out into the fluid reservoir. The weight of the car and the cargo pushes

down on the piston, which drives the fluid into the reservoir. The car gradually

descends. To stop the car at a lower floor, the control system closes the valve again.

Various Use of Hydraulic Lifts-

Table lifts, and positioners are used for positioning the work material such that the

material to be worked on is placed at an ergonomically comfortable access points. Truck

or vehicle lifts are used to lift materials for the purpose of lading them onto the trucks,

which is done by lifting such materials to the height of the truck bed. Transport

companies, that transports heavy goods and machinery by roads commonly uses such

lifts. Personnel lifts, as the name implies, are used to move workers to materials or the

work area. This is done when it is more feasible to move personnel to the work area,

rather than moving the work area to the workers.

HYDRAULIC CRANES

Hydraulic truck cranes can lift thousands of pounds using the simple concept of

transmitting forces from point to point through a fluid. In a matter of minutes, these

machines are able to raise multi-ton bridge beams on highways, heavy equipment in

factories and even lift beachfront houses onto pilings. Hydraulic truck cranes vary in

lifting power. The hydraulic crane is based on a simple concept -- the transmission of

forces from point to point through a fluid. Most hydraulic machines use some sort of

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incompressible fluids, a fluid that is at its maximum density. Oil is the most commonly

used incompressible fluid for hydraulic machines, including hydraulic cranes. In a

simple hydraulic system, when a piston pushes down on the oil, the oil transmits all of

the original force to another piston, which is driven up. In a simple hydraulic system,

when one piston is pushed down, another piston is pushed up. A hydraulic pump creates

the pressure that moves the pistons. Pressure in a hydraulic system is created by one of

two types of hydraulic pumps:

a. Variable-displacement pump

b. Gear pump

Most hydraulic truck cranes use two-gear pumps that have a pair of inter-meshing gears

to pressurize the hydraulic oil. When pressure needs to increase, the operator pushes the

foot throttle to run the pump faster. In a gear pump, the only way to get high pressure is

to run the engine at full power. A 70-ton hydraulic truck crane uses a 12.7-L diesel

engine that generates up to 365 horsepower.

International work in hydraulics

BASCULE BRIDGE

A bascule bridge (sometimes referred to as a drawbridge) is a moveable bridge with a

counterweight that continuously balances the span, or "leaf," throughout the entire

upward swing in providing clearance for boat traffic. Tower Bridge,London is a

magnificient example of bascule bridge.Tower Bridge (built 1886–1894) is a combined

bascule and suspension bridge in London which crosses the River Thames. It is close to

the Tower of London, from which it takes its name, and has become an iconic symbol

of London.

When it was built, Tower Bridge was the largest and most sophisticated bascule bridge

ever completed ("bascule" comes from the French for "see-saw"). These bascules were

operated by hydraulics, using steam to power the enormous pumping engines. The

energy created was stored in six massive accumulators, as soon as power was required

to lift the Bridge, it was always readily available. The accumulators fed the driving

engines, which drove the bascules up and down. Despite the complexity of the system,

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the bascules only took about a minute to raise to their maximum angle of 86

degrees.Today, the bascules are still operated by hydraulic power, but since 1976 they

have been driven by oil and electricity rather than steam. The original pumping engines,

accumulators and boilers are now exhibits within the Tower Bridge Exhibition.

LOWRIDER

A lowrider (sometimes low rider) is an automobile or other vehicle modified so that its

ground clearance is less than its design specification. A lowrider is a customized car

originated by Mexican-Americans in Southern California. Many lowriders have

hydraulic suspension systems (modified suspension) so that their ride can change height

at the flip of a switch.

The 1964, Chevy Impala hardtop or convertible is one of the most popular lowriders.

Chevrolet Impala is usually sought after by car collectors.

Many Lowriders feature custom hydraulic suspensions that allow the driver to alter the

ride height at will. At first, aircraft pumps, valves, and hoses were used. Later aircraft

units were replaced by the liftgate trucks units .

These systems range from simple to complex and are usually measured by the number

of hydraulic pumps (generally 2 to 4) used to control the various hydraulic

combinations that ultimately produce a specific motion from the vehicle. These pumps

are powered by multiple batteries installed in a rack in the trunk of the vehicle. The

speed at which the car lifts depends partly on the voltage generated by these batteries,

which can range from 12 VDC all the way up to 120 VDC. The most common motions

are dipping/raising the four corners of the vehicle, dipping/raising the front or rear of

the vehicle (front, back), dipping/raising the sides of the vehicles (side to side, which

started around 1978), and lowering/raising the vehicle as a whole (pancake). A skilled

switch operator can manipulate their controls to raise one wheel completely off the

ground (3-wheel motion), or to hop one end of the car completely off the

ground.Around the mid-1970s, it was found that adding more batteries could get the

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front wheels to actually hop off the ground. This created a whole new sport with respect

to hydraulics in Lowriders. Cars at that time could lift the front wheels off the ground

about the height of a 12 ounce can.

Result

Hydraulic systems today uses 'incompressible' fluid which results in a greater, more

efficient & consistent work or power output. This is due to the fact that hydraulic fluid

molecules are able to resist compression under heavy load hence minimal energy loss is

experienced and work applied is directly transferred to the actuating surfaces.As

opposed to pneumatic system which uses air, a leakage in a hydraulic system is easier to

spot during ground maintenance operations. Hydraulic fluid operates very well in a very

hot working environment, it is able to sustain its airworthiness viscosity, density & fluid

temperature even if it subjected under extreme heat. This is specially important on

aircraft structures that is abundant of hot working conditions during flight operations.

The main drawback of all current hydraulic systems is that they require an expansion

tank, which increases the weight, volume, and price of the hydraulic system.Another

disadvantage includes the oxidation of the fluid (oil). Oxidation, or the chemical union

of oil and oxygen, is one of the primary causes for decreasing the stability of hydraulic

fluid.. The chemical reactions result in the formation of acids that can increase the fluid

viscosity and can cause corrosion. Polymerization and condensation produce insoluble

gum, sludge, and varnish that cause sluggish operation, increase wear, reduce

clearances, and plug lines and valves. The biggest contribution to oxidation include

temperature, pressure, water, contaminants, metal surfaces, and agitation as well. In

addition, even with slight air ingress into the oil, it starts to foam, creating conditions

favorable for the formation of air emulsions with very low density. This disturbs the

uniformity of movement of the working parts . Dissolved air in the oil disturbs the

uniformity of the hydraulic drive motor, influences the viscosity of oil, and decreases

the speed of the hydraulic equipment. In accordance with the laws of thermodynamics,

when air bubbles compress, they are heated up and transfer heat to the hydraulic fluid.

The hydraulic fluid transfers heat to the atmosphere, which as a result significantly

lowers the efficiency of hydraulic drive. If there was no gas in the working fluid, the

fluid will heat up less.

The above drawbacks can be overruled by the application of hydraulic drive with

closed working fluid circulation system.

Closed (or sealed) hydraulic systems are described as:

1. A system with an additional fueling system, to which the fuel pump has an expansion

tank, which communicates with the atmosphere

21

2. A system without the expansion tank, but with a double-rotating hydraulic pump

which operates the system reversely, and which spends a large amount of energy when

started.

Aim being – The creation of a compact, highly efficient, energy-saving, simple and

reliable hydraulic drive unit, providing ample technological and operational capabilities

through the implementation of sealed hydraulic machinery which does not have contact

with the air.

The Scope of Use- The invention can be widely used in mechanical engineering,

machine building, shipbuilding, and aircraft building.

The technical result – An increase in pressure characteristics of the hydraulic drive,

which leads to an increase in speed of operation of the machine.

The economic effect – Is achieved by creating an initial overpressure at the fluid inlet

in the pump.

Implementation of the hermetically sealed system allows the hydraulic drive to work

independently of areal position, regardless of atmospheric pressure and the force of

gravity, and also prevents the formation of condensate during the operational process of

the hydraulic drive. Moreover, execution of the sealed system allows to deaerate the

working fluid after filling the system, as a result of which the working fluid will heat

less during operation, and the absence of dissolved air in the working fluid will no

longer disturb the uniformity of the hydraulic motor machine.

My contribution

No project is ever growing full blown from the researcher’s head. It has hands to help it

along the way. We as a team worked hand in hand under the guidance of Dr.

Siddheshwar Chopra.

My individual contribution is the second part of the research, FLUID , I’ve collected all

the information concerning fluids. Creating the steps forward to the understanding of

the applications of the hydraulic fluids. I’ve studied the various characteristics of fluids ,

the obsevations and methodologies of hydraulic fluids have been put forward by me.

I’ve tried my best to cover all that relates to the objective of our project.

Working on this project has been immensely enjoyable and I have gained much

beneficial information which will surely help me in my future.

22

References

For Basic hydraulics –

Computer applications in hydraulic engineering by Haestad methods

For Hydraulic Fluids

• Hydraulics from Encyclopedia Britannica (http://www.britannica.com)

• Hydraulics types of Hydraulics Pumps (http://www.hydraulicpumps.co.uk)

• Biodegradable Hydraulic Fluids from hydro safe (http://www.hydrosafe.com/)

• Fire resistant hydraulic fluids from Machinery Lubrication

(http://www.machinerylubrication.com)

• Fire resistant from Hydraulics Pneumatics(http://hydraulicspneumatics.com)

• Petroleum Jelly from pump zone(http://www.pump-zone.com)

• Safety Measures from Sauer-Danfoss (www.sauer-danfoss.com)

• Precaution from Hydraulic Facts(www.hydraulicfacts.com)

• Books From college Library

• Magazines on hydraulics like fluid power general and on website

(http://fluidpowerjournal.com/)

Websites for hydraulic lift –

www.hydraulicmania.com

For Hydraulic Brakes-

http://auto.howstuffworks.com/auto-parts/brakes/brake-types/brake.htm

For Pascal's law-

http://www.hydraulicstroubleshooter.com

Electronic books

A Textbook of fluid mechanics and hydraulic machines by Dr. R.K. bansal

edition revised edition 9 2010

(hydraulic press page no.1041)

(hydraulic lift page no. 1056)

Journals on hydraulic engineering-

http://ascelibrary.org/journal/jhend8