A Seminar Report on

“DOMESTIC HYDROPOWER PLANT”

Submitted toVISVESVARAYA TECHNOLOGICAL UNIVERSITY

BELGAUM

BACHELOR OF ENGINEERING

INMECHANICAL ENGINEERING

Under the Guidance ofMr. VENKATE GOWDA.T

B.E., M.Tech (Design)

Lecturer, Department of Mechanical Engineering

AMARDEEP 1SG08ME004

SAPTHAGIRI COLLEGE OF ENGINEERINGBangalore-560 057

SAPTHAGIRI COLLEGE OF ENGINEERING# 14/5, Chikkasandra, Hesaraghatta Main Road, Bangalore-560

057

Department of Mechanical Engineering

CERTIFICATE

Certified that the seminar report entitled “DOMESTIC

HYDROPOWER PLANT” carried out by Mr. AMARDEEP,

USN – 1SG08ME004, a bonafide student of SAPTHAGIRI

COLLEGE OF ENGINEERING in partial fulfillment for the

award of Bachelor of Engineering in Mechanical Engineering of

the Visvesvaraya Technological University, Belgaum during the

year 2011-12.

Name & Signature of the Guide Name & Signature of the H.O.D

Name & Signature of the Seminar Co-ordinator

ACKNOWLEDGEMENT

I express my deep gratitude to almighty, the supreme guide, for bestowing

his blessings upon me in my entire endeavor.

I would to like to express my sincere thanks to Dr. S H. Manjunath , Head of

Department, Mechanical Engineering Department, Sapthagiri College of

Engineering for all his assistance.

I wish to express my deep sense of gratitude to Mr. Venkate Gowda.T,

lecturer, Department of Mechanical Engineering who guided me through-out

the seminar. His overall direction and guidance has been responsible for the

successful completion of the seminar.

I would also like to thank Lecturer Mr. for his valuable suggestions.

Finally, I would like to thank all the faculty members of the Department of

Mechanical Engineering and my friends for their constant support and

encouragement.

ABSTRACTHydropower plants (HPP) are energy capacities which have negligible operation costs comparing with the high investments because of the water as natural and sustainable energy resource. The energy generation from hydropower plants cover a small part of total electricity needs in mainly because of limited water inflow. On the other side comparing with the fossil fired power plants, the hydropower plants are environmentally friendly and sustainable resource of energy. The electricity generation is strongly dependant on lignite thermal power plants (TPP)which can cover 70-80 % , and the rest is covered from hydropower and electricity import. The hydropower potential in existing HPP is between 800 GWh and 1500 GWh of electricity generation in a year depends on hydrology.The main HPP in Macedonia are Vrutok, Vrben and Raven in Mavrovo basin, Globocica and Spilje inCrn Drim basin, Tikves from Crna reka basin, and Kozjak, Sv. Petka and Matka from Treska basin.This paper gives the overall of technical characteristics of existing HPP units in Macedonia, as well aseconomical and technical parameters for new candidates. On the basis of natural water inflow bymonth, it will be calculated the monthly electricity generation, water discharge, variation of water levelin the reservoirs, and others. On the other side the paper will give some statistical points of naturalwater inflow and energy generation of the HPP taking into account the hydrology conditions for wet,average or dry season.

1. INTRODUCTION:

Hydropower is energy from water sources such as the ocean, rivers and waterfalls. “microhydro” means which can apply to sites ranging from a tiny scheme to electrify a single home,to a few hundred kilowatts for selling into the National Grid. Small-scale hydropower is one of the most cost-effective and reliable energy technologies to be considered for providingclean electricity generation. The key advantages of small hydro are:_ High efficiency (70 - 90%), by far the best of all energy technologies._ High capacity factor (typically >50%)_ High level of predictability, varying with annual rainfall patterns_ Slow rate of change; the output power varies only gradually from day to day (not from minute to minute)._ A good correlation with demand i.e. output is maximum in winter._ It is a long-lasting and robust technology; systems can readily be engineered to last for 50 years or more.It is also environmentally benign. Small hydro is in most cases “run-of-river”; in other wordsany dam or barrage is quite small, usually just a weir, and little or no water is stored.Therefore run-of-river installations do not have the same kinds of adverse effect on the local environment as large-scale hydro.

2. BLOCK DIAGRAM:

Fig 2:

In the absence of an applied field, MR fluids are reasonably

well approximated as Newtonian liquids. For most engineering

applications a simple Bingham plastic model is effective at

describing the essential, field-dependent fluid characteristics. A

Bingham plastic is a non-Newtonian fluid whose yield stress must

be exceeded before flow can begin; thereafter, the rate-of-shear vs.

shear stress curve is linear. In this model, the total yield stress is

given by:

Where:

= yield stress caused by applied magnetic field

= magnitude of magnetic field

= shear rate

= field-independent plastic viscosity defined as the slope of

the measured shear stress vs. shear strain rate relationship,

i.e., at H=0.

Fig 2.1: Graph to illustrate Viscosity v/s Shear Rate in a MR Fluid.

3. WORKING PRINCIPLE:

Applying a magnetic field to Magnetorheological fluids

causes particles in the fluid to align into chains.

Fig 3.

When some low-density MR fluids are exposed to rapidly

alternating magnetic fields, their internal particles clump together.

Over time they settle into a pattern of shapes that look a bit like

fish viewed from the top of a tank. Such clumpy MR fluids don’t

stiffen as they should when magnetized. The fish tank pattern is

fragile and takes about an hour to fully develop. It doesn’t occur in

MR fluids that are constantly mixed and agitated, as in a car’s

suspension, but it could prove troublesome in other situations.

Fig 3.1.

Above: The structure of particles in an MR fluid gradually changes

when an alternating magnetic field is applied. The leftmost picture

shows an MR fluid after 1 second of exposure to a fast-changing

magnetic field. The suspended particles form a strong, fibrous

network. The pictures to the right show the fluid after 3 minutes,

15 minutes and 1 hour of exposure. The particles have formed

clumps that offer little structural support.

4. WHAT MAKES A GOOD M R FLUID?

The most common response to the question of what makes a

good MR fluid is likely to be "high yield strength" or "non-

settling". However, those particular features are perhaps not the

most critical when it comes to ultimate success of a

Magnetorheological fluid. The most challenging barriers to the

successful commercialization of MR fluids and devices have

actually been less academic concerns.

As anyone who has made MR fluids knows, it is not hard to

make a strong MR fluid. Over fifty years ago both Rabinow and

Winslow described basic MR fluid formulations that were every bit

as strong as fluids today. A typical MR fluid used by Rabinow

consisted of 9 parts by weight of carbonyl iron to one part of

silicone oil, petroleum oil or kerosene.1 To this suspension he

would optionally add grease or other thixotropic additive to

improve settling stability. The strength of Rabinow’s MR fluid can

be estimated from the result of a simple demonstration that he

performed. Rabinow was able to suspend the weight of a young

woman from a simple direct shear MR fluid device. He described

the device as having a total shear area of 8 square inches and the

weight of the woman as 117 pounds. For this demonstration to be

successful it was thus necessary for the MR fluid to have yield

strength of at least 100 KPa.

MR fluids made by Winslow were likely to have been

equally as strong. A typical fluid described by Winslow consisted

of 10 parts by weight of carbonyl iron suspended in mineral oil.2

To this suspension Winslow would add ferrous naphthenate or

ferrous oleateas a dispersant and a metal soap such as lithium

stearate or sodium stearate as thixotropic additive. The

formulations described by Rabinow and Winslow are relatively

easy to make. The yield strength of the resulting MR fluids is

entirely adequate for most applications. Additionally, the stability

of these suspensions is remarkably good. It is certainly adequate

for most common types of MR fluid application. As early as 1950

Rabinow pointed out that complete suspension stability, i.e. no

supernatant clear layer formation, was not necessary for most MR

fluid devices. MR fluid dampers and rotary brakes are in general

highly efficient mixing devices.

5. M R FLUIDS IN DAMPERS:

As motion control systems become more refined, vibration

characteristics become more important to a system’s overall design

and functionality. Engineers, however, have tended to look at

motion control and vibration as separate issues. Motion control, it

might be said, presents fairly familiar design engineering problems

while vibration suggests more subtle problems. Few design

engineers have either the hands-on experience or the training to

address both sets of problems in a single design solution.

Fig 5: MR Fluid Damper

Most devices use MR fluids in a valve mode, direct-shear

mode, or combination of these two modes. Examples of valve

mode devices include servo valves, dampers, and shock absorbers.

Examples of direct-shear mode devices include clutches, brakes,

and variable friction dampers

. In valve mode When the piston in a MR fluid damper

moves, the MR fluid jets through the orifices quite rapidly causing

it to swirl and eddy vigorously even for low piston speed.

Similarly, the shear motion that occurs in a MR brake causes

vigorous fluid motion. As long as the MR fluid does not settle into

a hard sediment, normal motion of the device is generally

sufficient to cause sufficient flow to quickly remix any stratified

MR fluid back to a homogeneous state. For a small MR fluid

damper two or three strokes of a damper that has sat motionless for

several months are sufficient to return it to a completely remixed

condition.

Except for very special cases such as seismic dampers, lack

of complete suspension stability is not a necessity. It is sufficient

for most applications to have a MR fluid that soft settles – upon

standing a clear layer may form at the top of the fluid but the

sediment remains soft and easily remixed. Attempting to make

these MR fluids absolutely stable may actually compromise their

performance in a device. One of the areas where MR fluids find

their greatest application is in linear dampers that effect semi-

active control. These include small MR fluid dampers for

controlling the motion of suspended seats in heavy duty trucks,

larger MR fluid dampers for use as primary suspension shock

absorbers and struts in passenger automobiles and special purpose

MR fluid dampers for use in prosthetic devices.

In all of these devices one of the most important fluid

properties is a low-off state viscosity. While in all of these

examples having a MR fluid with high yield strength in the on-

state is important, it is equally important that the fluid also have a

very low off state. The very ability of an MR fluid device to be

effective at enabling a semi-active control strategy such as “sky -

hook” damping depends on being able to achieve a sufficiently low

off-state. Care must be taken in choosing fluid stabilizing additives

so that they do not adversely affect the off-state viscosity.

Earthquake dampers and other some other special

applications in which the device will sit quiescent for very long

periods of time represent special cases where fluid stability issues

may have overriding importance. Because of the transient nature of

seismic events these dampers never see regular motion, which can

be relied on to keep the fluid mixed. This lack of motion also has it

benefit. Unlike dampers used in highly dynamic environments,

seismic dampers do not need to sustain millions of cycles. The fact

that durability and wear are not issues gives the fluid designer

grater latitude to formulate a highly stable fluid. MR fluids for

these applications are typically formulated as shearing thinning

thixotropic gels.

6. APPLICATIONS OF M R FLUIDS:

MR fluids find a variety of applications in almost all the

vibration control systems. It is now widely used in automobile

suspensions, seat suspensions, clutches, robotics, design of

buildings and bridges, home appliances like washing machines etc.

Before discussing the above said applications in detail it is

desirable to go through the behavior of MR fluids on different

types of loading and what are the design considerations provided to

compensate this.

6.1 MR fluids on impact and shock loading:

Investigations on the design of controllable

Magnetorheological (MR) fluid devices have focused heavily on

low velocity and frequency applications. The extensive work in

this area has led to a good understanding of MR fluid properties at

low velocities and frequencies. However, the issues concerning

MR fluid behavior in impact and shock applications are relatively

unknown.

To investigate MR fluid properties in this regime, MR

dampers were subjected to impulsive loads. A drop-tower test

facility was developed to simulate the impact events. The design

includes a guided drop-mass released from variable heights to

achieve different impact energies. The nominal drop-mass is 55 lbs

and additional weight may be added to reach a maximum of 500

lbs. Throughout this study; however, the nominal drop-mass of 55

lbs was used. Five drop-heights were investigated, 12, 24, 48, 72

and 96 inches, corresponding to actual impact velocities of 86, 127,

182, 224 and 260 in/s.

Two fundamental MR damper configurations were tested, a

double-ended piston design and a mono-tube with nitrogen

accumulator. To separate the dynamics of the MR fluid from the

dynamics of the current source, each damper received a constant

supply current before the impact event. A total of five supply

currents were investigated for each impact velocity.

After reviewing the results, it was concluded that the effect of

energizing the MR fluid only leads to “controllability” below a

certain fluid velocity for the double-ended design. In other words,

until the fluid velocity dropped below some threshold, the MR

fluid behaved as if it was not energized, regardless of the strength

of the magnetic field. Controllability was defined when greater

supply currents yielded larger damping forces.

For the mono-tube design, it was not possible to estimate the

fluid velocity due to the dynamics of the accumulator. It was

shown that the MR fluid was unable to travel through the gap fast

enough during the initial impact, resulting in the damper piston and

accumulator piston traveling in unison. Once the accumulator

bottomed out, the fluid was forced through the gap. However, due

to the energy stored in the accumulator and the probable fluid

vaporization, it was impossible to determine the fluid velocity and

in many cases the damper did not appear to become controllable.

In conclusion, the two designs were compared and general

recommendations on designing MR dampers for impulsive loading

were made. Possible directions for future research were presented

as well.

6.2 MR fluid in automobile clutches

MR fluids are increasingly being considered in variety of

devices such as shock absorbers, vibration insulators, brakes or

clutches. The activation of MRF clutch’s built-in magnetic field

causes a fast and dramatic change in the apparent viscosity of the MR

fluid contained in the clutch. The fluid changes state from liquid to

semi-solid in about 6 milliseconds. The result is a clutch with an

infinitely variable torque output.

6.3 Double plate MRF clutch design:

Bans Bach, proposed a double-plate and a multi-plate MRF

torque transfer apparatus with a controller that adjusts the input

current. The apparatus is proposed to be placed between the engine of

a car and its differential. Gopalswamy suggested a MRF clutch to

minimize reluctance for fan clutches. Gopalswamy also studied a

controllable multi-plate MR transmission clutch. This clutch was also

designed to be placed between the engine and differential. Hampton

described a design of MRF coupling with reduced air gaps and high

magnetic flux density. Carlson proposed a MR brake with an

integrated flywheel.

The figure below shows the prototype of a double plate magneto

rheological fluid clutch.

Fig 6.3: Double plate MRF clutch design

The MR fluid is located in the gap between the input and output

plates, with the diameter of 51.94 mm. These plates are connected to

30 mm diameter input and output shafts. The shafts are supported by

deep groove ball bearings, which are press-fitted into the side caps.

The electromagnet circuit of this clutch consists of an electromagnetic

coil, which is wound around an electromagnetic core. This assembly

is located inside a 152.4 mm outer diameter casing with 6.35 mm wall

thickness, which is also acting as a return path for the magnetic field.

Two O-rings are located in the grooves machined on the

circumferences of plates to prevent leakage of MR fluid. The MRF

clutch is activated by a power supply connected to two ends of the

Electromagnet. The total width of the clutch is 31.75 mm.

The graph above shows magnetic field strength as a function of

radius in the MRF section. From the graph it can be observed that the

magnetic field increases with increasing radial distance from the

rotational axis. This is a desirable outcome since the contribution of

the resulting shear yield stress on the torque transmitted increases

with increasing radial distance.

The performance of a double-plate magneto-rheological fluid

limited slip differential clutch is studied using two types of MR

fluids. Theoretical and experimental analyses have illustrated that this

MR fluid clutch can transfer high controllable torques with a very fast

time response.

6.4 MR fluid in automotive suspensions:

Fig 6.4: Automotive Suspension.

MR technology enables new levels of performance in

automotive primary suspension systems. Shock absorbers incorporate

magneto rheological fluids to provide real-time optimization of

suspension damping characteristics that improve ride and handling.

MR fluid controllable damping technology outperforms all existing

passive and active suspension systems.

The MR fluid sponge damper requires neither seals nor

bearings, and uses the same inexpensive components found in

existing passive dampers, but with a few important modifications.

The damper consists of a layer of open-celled, polyurethane foam, or

other suitable absorbent matrix materials, saturated with ~3 ml of MR

fluid surrounding a steel bobbin and coil

Together these elements form a piston on the end of the shaft

that is free to move axially inside a steel housing that provides the

magnetic flux return path. Damping force is proportional to the

sponge’s active area.

The application of a magnetic field causes the MR fluid in the

matrix to develop yield strength and resist shear motion. The amount

of force produced is proportional to the area of active MR sponge that

is exposed to the magnetic field. This arrangement can be applied in

both linear and rotary configurations wherever a direct shear mode of

operation would be used.

6.5 MR fluid in washing machines:

A good example of unwanted vibratory motion is a washing

machine in its spin cycle trying to walk out of the room. MR damping

can correct this and other problem vibrations.

The common household washing machine represents a standard

compromise between controlling vibration associated with the spin

cycle and achieving optimum system performance and efficiency. The

tub in a conventional machine is suspended by a number of coil

springs that provide mechanical support as well as vibration isolation

at high frequency. To prevent potentially damaging vibratory

excursions when the drum velocity passes through resonance as it

accelerates during the ramp-up to the spin cycle, static vibration

dampers are added to the suspension.

Conventional dampers easily control the tub’s motion at

resonance; they can significantly degrade high-speed vibration

isolation. This tendency limits the size of the tub and to some extent

dictates the dimensions of the housing that must accommodate the

overall motion of the tub.

Because many households have only a washing machine and not

a dryer, tub speeds are reaching 2000 rpm, effectively becoming

centrifuges that remove almost all the water from the wash load. In

fact, manufacturers have had to reduce the size of the drain holes in

the tub to prevent extrusion of small items of clothing during the spin

cycle.

To achieve this level of performance, manufacturers have

incorporated a controllable damping system designed around

Magnetorheological (MR) fluid.

Fig 6.5: MR Fluid in washing machine.

Conventional springs and Magnetorheological dampers work

together to stabilize a home washing machine during the spin cycle.

The dampers control vibrations as the tub passes through resonance;

at the highest speeds the dampers are switched off and vibration

isolation is provided by the mechanical springs that support the tub.

These can simply be turned off at high spin speeds for an increased

degree of vibration isolation.

Fig 6.5.2: MR Fluid dampers in washing machine.

By activating the damper while the washing machine tub is

passing through resonance, a degree of vibration control is achieved

not possible with conventional springs alone. The damping

mechanism is switched off at the greatest speeds, when the

mechanical springs provide vibration isolation.

At high speed, the MR sponge dampers are turned off to enable

a high level of vibration isolation. With enhanced vibration control,

the drum may be made larger or the housing smaller since it must

accommodate less overall tub motion. Ideally, each of a pair of

controllable dampers would have to provide 50–150 N of damping

force when energized and a low residual force of <5 N when turned

off.

The application of Magnetorheological fluids for damping is a

unique and novel approach to an age-old problem. The repetitive

"thud" of a washing machine imbalance is inefficient. It does not dry

the clothes as well as it should and the peak energy demand is higher.

Then there is the cost in energy, to dry wetter clothes. Vibration

should be viewed as wasted energy.

6.6 MR fluid in seismic and wind mitigation:

Civil engineers in the construction industry are incorporating

MR Technology into the structural engineering of buildings and

bridges. The system is relatively inexpensive, needs little

maintenance and requires very little power to operate. A damping

system utilizing MR fluid dampers works similarly to an automotive

shock absorber, protecting the structure from earthquakes and

windstorms. When properly harnessed, the adaptability of MR

dampers can help protect a building or bridge during a severe

earthquake.

Real-time damping is controlled by the increase in yield stress of the

MR fluid in response to magnetic field strength. The response time of

the fluid damping is on average 60-milliseconds as the magnetic field

is changed. Seismic motion causes one floor to shear relative to the

next floor as low-order modes of the building are excited. Excessive

motion that is potentially damaging to the building and its contents is

controlled by dissipating mechanical energy in a distributed array of

dampers.

In giant bridges stay cables are prone to vibration due to wind

and rain effects. Smart dampers have the potential efficiency several

times that of standard oil dampers. MR Dampers are currently being

used on the Dongting Bridge in China.

So Magnetorheological fluid dampers can be considered as an

excellent solution for all vibrational problems associated with

constructional industries

6.7 MR fluid in seat suspensions:

In today’s pupil transportation, trucking and transit industries,

driver safety can never be compromised. MR fluid technology has

proven capability to reduce topping and bottoming: Bottoming that

can injure drivers and Topping that can lead to loss of control of the

vehicle.

Seating equipped with MR dampers is the only product that

offers both safety and health benefits for drivers. Unlike standard air

suspended seats, which compromise shock and vibration control, the

MR technology is the only solution that automatically adapts to both

the driver’s body weight and continually changing levels of shock and

road vibration, improving driver responsiveness and control while

reducing fatigue and risk of injury.

6.8 MR fluid as robot blood:

Astronauts onboard the International Space Station are studying

strange fluids that might one day flow in the veins of robots. MR

fluids are liquids that harden or change shape when they feel a

magnetic field.

The nervous systems of future robots might use MR fluids to move

joints and limbs in lifelike fashion

7. ADVANTAGES OF M R DAMPERS:

The MR fluid sponge damper requires neither seals nor

bearings, and uses the same inexpensive components found in

existing passive dampers, but with a few important modifications.

The damper consists of a layer of open-celled, polyurethane foam, or

other suitable absorbent matrix materials, saturated with ~3 ml of MR

fluid surrounding a steel bobbin and coil.

During passage through resonance, these controllable dampers

may be energized to provide a high level of damping which protects

the associated machine.

At high speed, the MR sponge dampers are turned off to enable

a high level of vibration isolation. Ideally, each of a pair of

controllable dampers would have to provide 50–150 N of damping

force when energized and a low residual force of <5 N when turned

off.

The power requirements for controllable MR fluid dampers are

so low that a net energy saving might be realized. Effective resonance

control typically requires ~10 W of input power to the MR dampers

for ~5–10 s, as the drum speed ramps through criticality. The amount

of power is readily available from existing onboard electronics in a

standard machine.

This can be explained with the help of the graph transmitted

force vs spin speed given below.

The rotational motion of the inner drum or agitator in a washing

machine, along with any load imbalance, creates a disturbing force

that excites vibratory motion of the tub that can become excessive

when the drum speed is near or at resonance.

Many of the benefits of passive damping schemes built around MR

technology are intuitive:

i. Efficiency

Washing machines achieve greater performance in terms

of higher spin speeds without the increased energy

consumption of more powerful motors.

With heightened vibration control, tubs in washing

machines can be designed larger and the housing smaller.

Machines can accurately weigh loads and thus control the

use of water and detergent.

Damages caused to the machine during resonance can be

avoided.

ii. Functionality

The damping system uses onboard electronics.

No additional operator control is required.

MR provides real-time controllability.

iii. Cost

Because existing materials are used, the slight increase in

materials cost is balanced by improved energy efficiency.

iv. System Integration

Additional electronic controls are easily adaptable to the

existing machine’s electronics footprint.

8. LIMITATIONS OF M R DAMPERS:

One major limitation of these MR dampers is the high cost

required for the installation. This can be neglected taking into account

the considerable increase in the efficiency of the associated machine.

MR dampers are now using temporary magnets which require

an applied magnetic field of 150–250 kA/m. Latest technologies

permits the use of permanent magnets also.

9. ADVANCEMENT IN M R FLUID TECHNOLOGY:

In addition to cost-sensitive applications such as washing

machines, MR fluid dampers are being used in rotary brakes for

exercise equipment and pneumatic systems; in complete semi active

damper systems for heavy-duty truck seat suspensions; in adjustable

linear shock absorbers for racing cars; and in semi active suspensions

for passenger cars.

Now under commercial development are very large MF fluid

dampers designed for seismic damage mitigation in civil engineering

structures such as buildings and bridges.

Finally, the technology is being investigated for applications in

vehicular steer-by-wire devices and medical equipment such as the

joints of prosthetic limbs.

The nervous systems of future robots might use MR fluids to

move joints and limbs in lifelike fashion. There are many potential

applications that make these fluids very exciting." For example, MR

fluids flowing in the veins of robots might one day animate hands and

limbs that move as naturally as any humans. Book makers could

publish rippling magnetic texts in Braille that blind readers could

actually scroll and edit. It might even be possible to train student

surgeons using synthetic patients with MR organs that flex and slices

like the real thing.

New developments in MR fluid technology allow the use of

permanent magnets which has lots of advantages. The question often

arises asking if it is possible to use a permanent magnet to bias a MR

fluid valve or device at a mid-range condition. Current could then be

applied to the accompanying electromagnetic coil to cancel the

magnetic field and open the valve. Alternatively, a reverse current

could be applied to the coil to add to the magnetic field taking the

device to a higher–range condition. One motivation for creating such

a system is to provide a fail-safe mode of operation wherein the

device remains in a locked condition when power is lost. Another

motivation may be energy conservation in systems intended to remain

closed or locked for extended periods of time and then only open

momentarily.

10. MORE FAR-OUT APPLICATIONS OF M R FLUIDS:

Magneto-liquid mirror telescopes that bend and deform to

cancel the twinkling of starlight.

Prosthetic limbs for humans (a prosthetic knee based on

Lord Corporation MR fluid technology is already

available.)

Active engine mounts that reduce vibration and quiet noise

before it can get into a vehicle.

Shock absorbers for payloads in the space shuttle.

Active hand grips that conform to the shape of each

individual hand or fingers.

11. CONCLUSION:

Magneto rheological fluids are actually amazing magnetic

fluids. MR fluid development is of course a balancing act that is

highly coupled with MR device design. MR fluid durability and life

have been found to be more significant barriers to commercial

success than yield strength or stability. Amenability of a particular

MR fluid formulation to being scaled to volume production must also

be considered. Challenges for future MR fluid development are fluids

that operate in the high shear regime of 104 to 106 sec-1.thus MR

fluids can be considered as a better way of controlling vibrations. The

key to success in all of these implementations is the ability of MR

Fig 10

fluid to rapidly change its rheological properties upon exposure to an

applied magnetic field.

Fig 11. Magnetorheological Fluid Suspensions

12. REFERENCES:

1. J. David Carlson, “What Makes a Good MR Fluid?,” 8th

International Conference on ER Fluids and MR Fluids Suspensions,

Nice, July 9-13, 2001.

2. LORD Materials Division, “Permanent - Electromagnet System,”

Engineering Note, March 2002.

3. Mark R. Jolly, Jonathan W. Bender, and J. David Carlson,

“Properties and Applications of Commercial Magnetorheological

Fluids,” SPIE 5th Annual Int Symposium on Smart Structures and

Materials, San Diego, CA, March 15, 1998.

4. T. Simon, F. Reitich, M. R. Jolly, K. Ito, and H. T. Banks (2001)

“On the Effective Magnetic Properties of Magnetorheological

Fluids,” Mathematical and Computer Modeling, 33, 273-284.

5. M.R. Jolly (1999) “Properties and Applications of

Magnetorheological Fluids,” (Invited) Proc. of MRS Fall Meeting,

Vol. 604, Boston, MA, Nov. 29-Dec. 3, 1999.

6. J. D. Carlson, “Low-Cost MR Fluid Sponge Devices,” J. Intelligent

Systems and Structures, 10 (1999) 589-594.

7. J. David Carlson, “New Cost Effective Braking, Damping, and

Vibration Control Devices Made with Magnetorheological Fluid,”

Materials Technology, 13/3 (1998) 96-99.

8. A. J. Margida, K. D. Weiss and J. D. Carlson, “Magnetorheological

Materials Based on Iron Alloy Particles,” Int. J. Mod. Physics B, 10

(1996) 3335-3341.

ABSTRACT:

Hydro power plants convert potential energy of water into electricity.

It is a clean source of energy .The water after generating electrical

power is available for irrigation and other purposes. The first use of

moving water to produce electricity was a waterwheel on the Fox

River in Wisconsin in 1882. Hydropower continued to play a major

role in the expansion of electrical service early in this century around

the world. Hydroelectric power plants generate from few kW to

thousands of MW. They are classified as micro hydro power plants

for the generating capacity less than 100 KW. Hydroelectric power

plants are much more reliable and efficient as a renewable and clean

source than the fossil fuel power plants. This resulted in upgrading of

small to medium sized hydroelectric generating stations wherever

there was an adequate supply of moving water and a need for

electricity. As electricity demand soared in the middle of this century

and the efficiency of coal and oil fueled power plants increased, small

hydro plants fell out of favor. Mega projects of hydro power plants

were developed. The majority of these power plants involved large

dams, which flooded big areas of land to provide water storage and

therefore a constant supply of electricity. In recent years, the

environmental impacts of such large hydro projects are being

identified as a cause for concern. It is becoming increasingly difficult

for developers to build new dams because of opposition from

environmentalists and people living on the land to be flooded.

Therefore the need has arisen to go for the small scale hydro electric

power plants in the range of mini and micro hydro power plants.

There are no micro hydro power plants in Malaysia and the smallest

category of hydro power plants in Malaysia is mini hydro with a

capacity between 500 kW to 100 kW. This paper discusses the

conceptual design and development of a micro hydro power

plant .The overall estimation and calculation of a 50 kW power plant

has been carried out. Software is also developed using MATLAB to

calculate the total head, discharge rate, type of turbine for the micro

hydro power plants, once the capacity is known.