report tesla turbine

MAJOR PROJECT REPORT ON TESLA TURBINE

SHAHEED BHAGAT SINGH STATE TECHNICAL CAMPUS 1

CHAPTER 1

INTRODUCTION

The objective of the project is to study

the constructional features of a TESLA

TURBINE and making it feasible for

economical and consistent use. Nikola

Tesla invented the bladeless turbine in

1913. This turbine is a radial turbine. A

Radial turbine is a turbine in which the

flow of the working fluid is radial to the

shaft (i.e., 90degrees). The Tesla turbine

is also known as the boundary layer

turbine, cohesion-type turbine, and

Prandtl layer turbine in general.

The Tesla turbine is a bladeless

centripetal flow turbine. It is referred to as a bladeless turbine because it uses

the boundary layer effect and not a fluid impinging upon the blades as in a

conventional turbine. The Tesla turbine is also known as the boundary layer

turbine, cohesion-type turbine. Bioengineering researchers have referred to it as a

multiple disk centrifugal pump. One of Tesla‟s desires for implementation of this

turbine was for geothermal power.

Tesla Turbine, though proposed by the famous Croatian engineer Nikola Tesla years

ago, is still to find its foot among the modern power turbines. Analysts are divided as

to what exactly is the main reason behind the Tesla Turbine not taking off as well as it

should have, given its unique factors. There are many reasons for this, but the general

agreement is that the low torque produced by its rotor is probably its biggest

drawback. After a thorough investigation about the various factors plaguing the

working of the Tesla Turbine, the need to change the working fluid from the current

air / water at room temperature became very evident. Since all the fluids used till now

have yielded a very low torque, it became very clear that a new fluid, which facilitates

high momentum transfer from the fluid to the rotor, was the need of the hour.

Thus, this study investigates the use of a new working fluid and also analyzes its

effects, structural and thermal, on the rotor. The structural and thermal effects analysis

indicates that the current Tesla Turbine rotor materials will fail to prevent the rotor

from excessive stress concentration and corrosion. Thus, with the proposal of a new

working fluid came the imperative of proposing a new material for Tesla Turbine

rotors, which will complement the new working fluid. As a result, this study proposes

two new aspects for a Tesla Turbine: a new working fluid and a new rotor material. It

is expected that once these proposals are implemented, the improved torque

Figure1.1 - Tesla Turbine



generation by the Tesla Turbine will improve its acceptance levels and lead to its

increased popularity.

Moreover talking about the structural analysis of the tesla turbine structural analysis

of the rotor components (turbine blades) have so far been mostly confined to

conventional turbines like steam turbines, gas turbines and wind turbines. These

studies dealt with the structural and dynamic stresses, the crack propagation etc.

experienced in actual working conditions by the turbine blades. Though analyses of

more specialized turbines like aero-engine turbines have been done, Tesla Turbine

analysis papers remain highly elusive.

Very few papers have been written researching Tesla Turbine because of its low level

of commercial adoption. This was designed, tested and analyzed a multiple-disk Tesla

type fan two-dimensionally using the conservation of angular momentum principle.

Their study showed that Tesla Turbines exhibited exceptionally low performance

characteristics, due to the low viscosity, tangential nature of the flow, and large

mechanical energy losses at both suction and discharge sections that are comparable

to the total input power. Their research determined the local and shearing stresses

developed within the rotor as also the power transmitted from the air to the rotor .

From this study, the main reason for low torque, low viscosity of the working fluid,

was identified and this principle played a significant role in the proposal of the new

working fluid later on in this study.

After discussing the relative motion of rotating surfaces, the transport equations

describing the flow between parallel rotating disks are derived, estimating the

boundary layer thickness under laminar and turbulent regimes, leading to expressions

yielding the width between consecutive disks. They have also described the device

behavior acting as an air compressor or water pump. Even they have stated in their

paper that a comprehensive discussion of the fluid mechanics involved in the design

of Tesla Turbine components has never taken place. From their analysis, it became

clear that virtually no consideration was ever given for exploring new materials for

the construction of Tesla Turbine rotors. This huge void had to be filled, but by doing

so, the close relation between the working fluid and the rotor material had to be taken

into account.

Armstrong made a modified Tesla Turbine and analyzed it way back in 1952. But in

those days, the science of composite materials was not advanced enough for him to

explore the use of laminated composite materials as rotor materials. But this study

does exactly that i.e. proposing the new rotor material but within the framework of the

laminar fluid characteristics of the new working fluid proposed.



1.1 History

A Tesla turbine is a quite unique technology. It was invented and patented by Nikola

Tesla on the 21st October 1909 at the United States Patent Office from experiments

done in England. The US patent 1061206 was granted on the 6th May 1913, although

historical documents suggest that that Tesla first showed a 200 horsepower (about

150kw) 16,000 RPM version on the 10th of July 1906 (on Tesla‟s 50th birthday).

From what Tesla wrote in the patent it seems his experiments were mainly done with

fluids but had confirmed it works with air as well. Tesla had his own personal

requirements for a generator for his laboratory. You have to remember use of

electrical power was still in its infancy which Tesla played a critical role developing

many of the electrical components we now take for granted. Typically Tesla found his

alternative and better way of generating power, using a steam boiler powering a tesla

turbine which in turn powered an AC generator.

Unlike conventional turbines, jet engines and most pumps, Tesla‟s turbine can be

designed to be reversible with no loss in efficiency. Normally compressed air, fluids

or steam is applied to the inlet and the turbine spins giving a mechanic rotational

output. However, it can also double up as a pump, by rotating the shaft the

air/fluid/steam can and be sucked and blown from the inlets / outlets. This makes it

unique in being a reversible turbine and a reversible pump. However efficiency

increases can be made by tailoring the pump to the medium. In other words an air

powered turbine may have some slight design changes compared to water powered

turbine.

Sadly unlike the work done with electricity the Tesla turbine never became popular

and was simply forgotten about. Only in the last few years has there been new

interest. Tesla turbines are also known as cohesion turbines, bladeless turbines,

boundary layer turbines and Prandtl layer turbines.

Interestingly, using the word "turbine" to describe Tesla's invention seems a bit

misleading. That's because most people think of a turbine as a shaft with blades -- like

fan blades -- attached to it. In fact, Webster's dictionary defines a turbine as

an engine turned by the force of gas or water on fan blades. But the Tesla turbine

doesn't have any blades. It has a series of closely packed parallel disks attached to a

shaft and arranged within a sealed chamber. When a fluid is allowed to enter the

chamber and pass between the disks, the disks turn, which in turn rotates the shaft.

This rotary motion can be used in a variety of ways, from powering pumps, blowers

and compressors to running cars and airplanes. In fact, Tesla claimed that the turbine

was the most efficient and the most simply designed rotary engine ever designed.



CHAPTER 2

CONSTRUCTION

The project mainly concentrates on use of muscular force to compress air which is

used as the working fluid in the turbine. Construction of the project can be categorised

in three parts as following:

1. Turbine

2. Air Compression Unit

3. Storage Unit

4. Power Generation Unit

The above mentioned parts are discussed in detail in the following sections.

2.1 TESLA TURBINE

A Tesla turbine consists of a group of smooth disks held together with spacers in

between them, with nozzles applying a moving fluid tangentially to the disk. The fluid

rotates the disk due to viscosity of the fluid and the adhesion of the surface layer of

the fluid to the disc. Since there are no projections in the rotor, it is very sturdy. All

the plates and washers are interference-fitted on to a shaft provided with bearings at

both ends. This construction allows free expansion and contraction of each plate under

the constantly changing combined effect of heat and centrifugal force. The other

advantages of such an arrangement are higher resultant active plate area and thus

more power, higher efficiency, reduced warping, diminished leakage and reduced

friction losses. The rotor is better suited for dynamic balancing and since surface

friction resists disturbing forces, a quiet running is ensured. Because of this and also

because of the flexibility of the discs, the turbine is insulated from damages which are

usually caused by vibration or turbulence.

2.1.1 Working Principle

When a fluid flows around the outside of a body, it produces a force that tends to drag

the body in the direction of the flow. The drag acting on a moving object such as a

ship or an airplane must be overcome by the propulsion system. Drag takes two

forms, skin friction drag and form drag. Skin friction drag is due to the viscous

shearing that takes place between the surface and the layer of fluid immediately above

it. This occurs on surfaces of objects that are long in the direction of flow compared to

then height. Such bodies are called streamlined. When a fluid flows over a solid

surface, the layer next to the surface may become attached to it (it wets the surface).

This is called the 'no slip condition'. The layers of fluid above the surface are moving

so there must be shearing taking place between the layers of the fluid. The shear stress

acting between the wall and the first moving layer next to it is called the wall shear

stress and denoted τw.



The result is that the velocity of the fluid u increases with height y. The boundary layer thickness δ is taken as the distance required for the velocity to reach 99% of UO. This layer is called the boundary layer and δ is the boundary layer thickness. Fig. 2.1 Shows how the velocity "u" varies with height "y" for a typical boundary layer. In a pipe, this is the only form of drag and it results in a pressure and energy lost along the length. A thin flat plate is an example of a streamlined object. Consider a stream of fluid flowing with a uniform velocity UO. When the stream is interrupted by the plate (Fig. 2.2), the boundary layer forms on both sides. The diagram shows what happens on one side only.

Figure 2.2- Boundary Layer

The boundary layer thickness δ grows with distance from the leading edge. At some

distance from the leading edge, it reaches a constant thickness. It is then called a fully

developed boundary layer.

The Reynolds number for these cases is defined as:

x is the distance from the leading edge. At low Reynolds numbers, the boundary layer

may be laminar throughout the entire thickness. At higher Reynolds numbers, it is

turbulent. This means that at some distance from the leading edge the flow within the

boundary layer becomes turbulent. A turbulent boundary layer is very unsteady and

the streamlines do not remain parallel. The boundary layer shape represents an

average of the velocity at any height. There is a region between the laminar and

turbulent section where transition takes place

The turbulent boundary layer exists on top of a thin laminar layer called the laminar

sub layer. The velocity gradient within this layer is linear as shown. A deeper analysis

would reveal that for long surfaces, the boundary layer is turbulent over most of the

Figure 2.1- Boundary Layer Thickness



length. Many equations have been developed to describe the shape of the laminar and

turbulent boundary layers and these may be used to estimate the skin friction drag.

Note that for this ideal example, it is assumed that the velocity is the undisturbed

velocity Uo everywhere outside the boundary layer and that there is no acceleration

and hence no change in the static pressure acting on the surface. There is hence no

drag force due to pressure changes.

Calculating Skin Drag

The skin drag is due to the wall shear stress τw and this acts on the surface area

(wetted area). The drag force is hence: R = τw x wetted area. The dynamic pressure is

the pressure resulting from the conversion of the kinetic energy of the stream into

pressure and is defined by the expression

.

The drag coefficient is defined as

Note that this is the same definition for the pipe friction coefficient Cf and it is in fact

the same thing. It is used in the Darcy formula to calculate the pressure lost in pipes

due to friction. For a smooth surface, it can be shown that CDf = 0.074(Re)x-1/5

(Re)x is the Reynolds number based on the length. (Re)x =

On a small area the drag is dR = τw dA. If the body is not a thin plate and has an area

inclined at an angle θ to the flow direction, the drag force in the direction of flow is

τw dA cosθ.

Figure 2.3 – Force Diagram

The drag force acting on the entire surface area is found by integrating over the entire

area.

R = ∮

F cos

Drag

F



2.1.2 Construction

Compared to a reciprocating engine, the Tesla turbine is simplicity incarnate. The two

most important parts of the turbine, the rotor and the stator, are explained ahead in

more detail.

Rotor

Unlike the conventional turbine, the Tesla turbine does not have blades and uses a

combination of disks and spacers instead. The diameter and number of the disks can

change depending upon factors concerned with a particular application. Each disk is

provided with openings surrounding the shaft. Between every two discs, there are

metal spacers provided to ensure a gap is maintained between discs, so as to ensure

free flow of fluid. Once a free flow is ensured, space should be provided for the fluid

to exit, and for that, the above mentioned openings are provided. All the discs and

spacers are interference-fitted on the shaft and thus their rotation is transferred to the

shaft. The rotor of the turbine is designed using compact disks and shaft in the center.

The detailed drawing of the designed rotor is provided below.

Figure 2.4 – Turbine Rotor



Stator

The rotor assembly is enclosed within a square stator, which is the stationary part of

the Tesla turbine. The square shape should be just slightly bigger than the rotor in

order to allow efficient flow of fluid. The stator also has an inlet in the form of a hole.

This is the fundamental design. To rotate the turbine, a high-pressure fluid is passed

through the hole provided at the top. The fluid makes its way through the rotor disks

and causes the rotor to rotate. Finally, the fluid exits from the exhaust ports at the

center of the turbine. The stator of the turbine consists of the following parts:

a. End Plates – The plates of the turbine are the covering at the two ends of the

casing. These plates are made of acrylic sheet. A detailed drawing of the end

plates is provided below.

i. Inner End Plates

Figure 2.5 – Inner Plate A, Inner Plate B



ii. Outer End Plates

Figure 2.6 – Outer Plate A

Figure 2.7 – Outer Plate B



b. Casing – The casing of turbine is cylindrical in shape and is made up of PVC.

The rotor of the turbine rotates in this cylindrical casing which is of slightly

larger diameter then the disks of the rotor. There is a hole provided at the top

of the casing which is for the inlet of the air through the nozzle. The detailed

drawing showing the casing of the turbine in shown below.

Figure 2.8 – Turbine Casing



c. Nozzle Assembly – The air is injected through the nozzle in the turbine. The

nozzle assembly consists of the main nozzle and the nozzle casing. This is by

far the most important element in achieving and fine tuning the efficiency of

the disk turbine. A properly designed nozzle has a complex shape that

determines the efficiency of converting gas pressure to shaft horsepower. The

nozzle of the turbine is simple in construction, cylindrical in shape and is

fabricated using lathe. The details of the nozzle and the nozzle casing are

shown in the drawing below.

Figure 2.9 – Nozzle

Figure 2.10 – Nozzle Casing



2.2 AIR COMPRESSION UNIT

The air compression unit consists of the exercising machine which is used as the

compressor for the system. The air is compressed by the muscular force applied on the

exercising machine by the user. This compressed air is transferred to the storage

cylinder via non-return valves. The compression unit comprises of the following

parts:

a. Foot Air Pump

b. Pneumatic Non-return Valves

2.2.1 Foot Air Pump

An air pump is a device for pushing air. Examples include a bicycle pump that are

used to aerate an aquarium or a pond via an air stone a gas compressor used to power

a pneumatic tool, air horn or pipe organ, a bellows used to encourage a fire; a vacuum

cleaner and a vacuum pump.

These pumps are often not specifically designed for bicycle use. They do not generate

very high pressures so do not work well for narrow road-bike tires, but are fine for

large low-pressure tires as found on mountain bikes.

The pump which we are using here is a foot pump, containing a heavy duty cylinder

of diameter 8cm working pressure is 0-100 Psi or 0-7 bar pressure. The pressure

gauge has been removed from it for our convenience and the proper transference of

pressurized air with the help of hose pipe.

2.2.2 Pneumatic Non-return Valve

It is commonly called as ANRV of 15 mm diameter

having a pressure resistance of 10 kg/cm².It is also

made of plastic material so that air leakage is minimum

or negligible. Pneumatic non-return valves are used

where a normal non-return valve would be ineffective.

This is for example where there is a risk of flood

water entering a site but an equal risk of pollution or

a chemical spills leaving a site and polluting the

environment. Pneumatic non-return valves are installed

below ground and can be used to pneumatically lock the

non-return valve closed thus containing a site in the

event of a spill. It is common practice to lock sites using

pneumatic non-return valves during the loading or

transferring of chemicals or hazardous waste. Pneumatic

non-return valves have a longer service life when

compared to pneumatic bladder systems.

Figure 2.11 – ANRV



2.3 STORAGE UNIT

The air compressed using the pumps is stored in a cylinder. A pressure gauge is

mounted on the cylinder for measuring the pressure inside the cylinder. The stored air

transferred to turbine for the required purpose. The flow of air to the turbine is

controlled by a gate valve. The storage unit consists of the following parts:

a. Cylinder

b. Pressure Gauge

c. Gate Valve

2.3.1 Cylinder

Now to store the pressurized air, we have used a cylinder of suitable capacity so that

air at pressure can enter the cylinder and then pressurized air from cylinder is passed

to the turbine.

Figure 2.12 – Cylinder

2.3.2 Pressure Gauge

It is used for measuring the pressure of air inside the cylinder. A pressure gauge is a

common component in operations from various industries across the world. But not

every gauge is created equally or made for every situation. WIKA Instrument

Corporation has been on the forefront of innovation and quality for pressure gauges

and pressure instruments for over 60 years, making us the pressure gauge expert for

diverse industries and applications. Gauges with bourdon tubes are the most common

pressure measuring devices used today. They combine a high grade of measuring



technology, simple operation, ruggedness and flexibility with the advantages of

industrial and cost-effective production. Needing no external power supply, bourdon

tube gauges are the best choice for most applications. Pressure gauges are crucial

components of most processing systems. In these environments, a pressure gauge

needs to be reliable, accurate and easy to read to help prevent failure in everyday

operations. Therefore, how a gauge is constructed and tested is extremely important

for reliability, safety and peace-of-mind. After all, failures can cost time, money and

productivity loss.

2.3.3 Gate Valve

We have used a plastic gate valve

having inner diameter of 15mm.

According to functioning of a simple

gate, same is the principle behind the

working of the gate valve. It is used

to transmit the pressurized air from

one hose pipe to other. In this, there

is no chance of leakage if the

connection is made by Teflon tape.

The gate valve, also known as

a sluice valve, is a valve that opens by

lifting a round or rectangular

gate/wedge out of the path of the fluid. The distinct feature of a gate valve is the

sealing surfaces between the gate and seats are planar, so gate valves are often used

when a straight-line flow of fluid and minimum restriction is desired. The gate faces

can form a wedge shape or they can be parallel. Gate valves are primarily used to

permit or prevent the flow of liquids, but typical gate valves shouldn't be used for

regulating flow, unless they are specifically designed for that purpose. Because of

their ability to cut through liquids, gate valves are often used in

the petroleum industry. For extremely thick fluids, a specialty valve often known as

a knife valve is used to cut through the liquid. On opening the gate valve, the flow

path is enlarged in a highly nonlinear manner with respect to percent of opening. This

means that flow rate does not change evenly with stem travel. Also, a partially open

gate disk tends to vibrate from the fluid flow. Most of the flow change occurs near

shutoff with a relatively high fluid velocity causing disk and seat wear and eventual

leakage if used to regulate flow. Typical gate valves are designed to be fully opened

or closed. When fully open, the typical gate valve has no obstruction in the flow path,

resulting in very low frictional loss. Gate valves are having either a rising or a non-

rising stem. Rising stems provide a visual indication of valve position because the

stem is attached to the gate such that the gate and stem rise and lower together as the

valve is operated.

.

Figure 2.13 – Gate Valve



2.4 POWER GENERATION UNIT

The power generated by the turbine is transferred to an electricity generator using a

pair of spur gear. The electricity then generated is can be used for the required

purposes. For the purpose here we have used it for lighting the LED‟s. The following

parts are covered in this unit:

a. Dynamo

b. Spur Gear

c. LED(Light Emitting Diode)

2.4.1 Dynamo

A dynamo is an electrical generator that produces direct current with the use of

a commutator. Dynamos were the first electrical generators capable of delivering

power for industry, and the foundation upon which many other later electric-power

conversion devices were based, including the electric motor, the alternating-

current alternator, and the rotary converter. Today, the simpler alternator dominates

large scale power generation, for efficiency, reliability and cost reasons. A dynamo

has the disadvantages of a mechanical commutator. Also converting alternating to

direct current using power rectification devices (vacuum tube or more recently solid

state) is effective and usually economic. The word dynamo (from the Greek word

dynamis; meaning power) was originally another name for an electrical generator, and

still has some regional usage as a replacement for the word generator. A small

electrical generator built into the hub of a bicycle wheel to power lights is called a hub

dynamo. The dynamo uses rotating coils of wire and magnetic fields to convert

mechanical rotation into a pulsing direct electric current through Faraday's law of

induction. A dynamo machine consists of a stationary structure, called the stator

which provides a constant magnetic field and a set of rotating windings called

the armature which turn within that field. The motion of the wire within the magnetic

field causes the field to push on the electrons in the metal, creating an electric current

in the wire. On small machines the constant magnetic field may be provided by one or

more permanent magnets larger machines have the constant magnetic field provided

one or more electromagnets which are usually called field coils. The commutator was

needed to produce direct current. When a loop of wire rotates in a magnetic field, the

potential induced in it reverses with each half turn, generating an alternating current.

However, in the early days of electric experimentation, alternating current generally

had no known use. The few uses for electricity, such as electroplating, used direct

current provided by messy liquid batteries. Dynamos were invented as a replacement

for batteries. The commutator is essentially a rotary switch. It consists of a set of

contacts mounted on the machine's shaft, combined with graphite-block stationary

contacts, called "brushes", because the earliest such fixed contacts were metal

brushes. The commutator reverses the connection of the windings to the external

circuit when the potential reverses, so instead of alternating current, a pulsing direct

current is produced.



2.4.2 Spur Gear

A gear is a rotating machine part having cut teeth, or cogs, which mesh with another

toothed part in order to transmit torque. Two or more gears working in tandem are

called a transmission and can produce a mechanical advantage through a gear

ratio and thus may be considered a simple machine. Geared devices can change the

speed, torque, and direction of a power source. The most common situation is for a

gear to mesh with another gear however a gear can also mesh with a non-rotating

toothed part, called a rack, thereby producing translation instead of rotation. The gears

in a transmission are analogous to the wheels in a pulley. An advantage of gears is

that the teeth of a gear prevent slipping. When two gears of unequal number of teeth

are combined a mechanical advantage is produced, with both the rotational speeds and

the torques of the two gears differing in a simple relationship. In transmissions which

offer multiple gear ratios, such as bicycles and cars, the term gear, as in first gear,

refers to a gear ratio rather than an actual physical gear. The term is used to describe

similar devices even when gear ratio is continuous rather than discrete, or when the

device does not actually contain any gears, as in a continuously variable transmission.

We have used the spur gears or straight-cut gears are the simplest type of gear. They

consist of a cylinder or disk with the teeth projecting radially, and although they are

not straight-sided in form, the edge of each tooth is straight and aligned parallel to the

axis of rotation. These gears can be meshed together correctly only if they are fitted to

parallel shafts. These when connected to the shaft of the turbine, transfer the motion

from one form to other. Its diameter was 6mm so one end of the shaft has been given

the radius of 6mm. as a result the inner side of the gear is fixed in the shaft of the

turbine.

Gear terminologies are as follow in the diagram drawn below:-

Figure 2.14 – Spur Gear



2.4.3 LED (Light Emitting Diode)

A light-emitting diode (LED) is a semiconductor light source. LEDs are used as

indicator lamps in many devices and are increasingly used for other lighting.

Appearing as practical electronic components in 1962, early LEDs emitted low-

intensity red light, but modern versions are available across the visible, ultraviolet,

and infrared wavelengths, with very high brightness. When a light-emitting diode is

forward-biased (switched on), electrons are able to recombine with electron

holes within the device, releasing energy in the form of photons. This effect is

called electroluminescence and the color of the light (corresponding to the energy of

the photon) is determined by the energy gap of the semiconductor. An LED is often

small in area (less than 1 mm2), and integrated optical components may be used to

shape its radiation pattern.

LEDs

present many advantages over

incandescent light sources

including lower energy consumption,

longer lifetime, improved physical

robustness, smaller size, and faster

switching. LEDs powerful enough for

room lighting are relatively expensive

and require more precise current

and heat management than

compact fluorescent lamp sources of

comparable output.

Light-emitting diodes are used in

applications as diverse as aviation

lighting, automotive lighting,

advertising, general lighting, and traffic

signals. LEDs have allowed new text,

video displays, and sensors to be

developed, while their high switching rates are also useful in advanced

communications technology. Infrared LEDs are also used in the remote control units

of many commercial products including televisions, DVD players, and other domestic

appliances.

Now LED is being lit by the rotational motion of the dynamo which is caused by the

working of the gear motor that is fitted inside the dynamo which is connected to the

main shaft of turbine. The motion from one shaft is passed to another by the means of

gear and thus effective lightening of LED is done and hence the main motive of

project is done that is the conversion of the one kind of energy to the other form by

the means of the bladeless turbine.

Figure 2.15 – Light Emitting Diode



CHAPTER 3

MATERIALS USED

Several kinds of materials are used for the fabrication of the project. The material

used for the fabrication purpose is carefully selected so that the required purpose is

fulfilled in the best economical way. Different materials used in the fabrication of the

project are discussed below.

3.1 ACRYLIC SHEET

Known by trade names such as Plexiglass, Acrylite, and Lucite, this material is great

for glazing, windows, cutting boards, or anywhere a clear material is needed. It has

better optical clarity than glass. It is light in weight and has good impact strength and

moreover it has clear surface.

Figure 3.1 – Acrylic Sheet

3.2 PVC PIPE

Polyvinyl chloride PIPE, commonly abbreviated PVC,

is the third-most widely produced plastic, after

polythene and epolypropylene. PVC is used in

construction because it is more effective than traditional

materials such as copper, iron or wood in pipe and

profile applications. It can be made softer and more

flexible by the addition of plasticizer. In this form, it is

Figure 3.2 – PVC Pipe



also used in clothing and upholstery, inflatable products and many applications in

which it replaces rubber.

3.3 COMPACT DISK

CD stands for "Compact Disc." CDs are circular discs that are 4.75 in (12 cm) in

diameter. The CD standard was proposed by Sony and Philips in 1980 and the

technology was introduced to the U.S. market in 1983. CDs can hold up to 700 MB of

data or 80 minutes of audio. The data on a CD is stored as small notches on the disc

and is read by a laser from an optical drive. The drives translate the notches (which

represent 1's and 0's) into usable data. The first CDs were audio CDs, which

eventually replaced audio tapes (which earlier replaced records). Audio CDs have the

advantage of allowing the user to jump to different places on the disc. CDs can also be

listened to an unlimited number of times without losing quality. Audio tapes can start

to lose quality after listening to them as few as ten times. This is because the laser that

reads the data on a CD doesn't put pressure on the disc, whereas the play heads on a

tape deck slowly wear away the magnetic strip on the tape. In 1985, CD-ROMs hit the

computer market. Because they could store far more information than floppy discs

(700 MB compared to 1.4 MB), CDs soon became the most common software format.

In 1988, the CD-R (CD-Recordable) technology was introduced, allowing computer

users to burn their own CDs.

Figure 3.3 – Compact Disks

3.4 BALL BEARINGS

A ball bearing is a type of rolling element bearing that uses balls to maintain the

separations between the bearing races. The purpose is to reduce rotational friction and

support radial and axial loads.it achieves this by using at least two races to contain the

walls and transmit the loads through the wall in most applications, one race is

stationary and the other is attached to the rotating assembly. As one of the bearing



races rotates it causes the rotate as well because the ball are rolling they have a much

lower coefficient of friction than if two flat surfaces were sliding against each other.

Bearing balls are manufactured to a specific grade, which defines its

geometric tolerance. The grades range from 2000 to 3, where the smaller the number

the higher the precision. Grades are written "GXXXX", i.e. grade 100 would be

"G100". The grades are divided into two categories: semi-precision and precision.

Grades 100 and greater are semi-precision balls and lower than that is precision balls.

The specification defines three parameters: surface integrity, size, and sphericity. The

surface integrity refers to surface smoothness, hardness, and lack of defects, such as

flats, pits, soft spots, and cuts. The surface smoothness is measured in two

ways surface roughness and waviness. The bearing used in the turbine is 6802.

Figure 3.4 – Ball Bearing



CHAPTER 4

WORKING

Adhesion and viscosity are the two properties of any fluid, these two properties work

together in the tesla turbine to transfer energy from the fluid to the rotor or vice versa.

As the fluid moves past each disk, adhesive forces cause the fluid molecules just

above the metal surface to slow down and stick. The molecules just above those at the

surface slow down when they collide with the molecules sticking to the surface. These

molecules in turn slow down the flow just above them. The farther one moves away

from the surface, the fewer the collisions affected by the object surface. At the same

time, viscous forces cause the molecules of the fluid to resist separation. This

generates a pulling force that is transmitted to the disk, causing the disk to move in

the direction of the fluid. The thin layer of fluid that interacts with the disk surface in

this way is called the boundary layer, and the interaction of the fluid with the solid

surface is called the boundary layer effect. As a result of this effect, the propelling

fluid follows a rapidly accelerated spiral path along the disk faces until it reaches a

suitable exit with proper use of the analytical results, the rotor efficiency using

laminar flow can be very high, even above 95%.

The reason why the Tesla turbine rotates with such high rpm can be found in two very

basic properties of fluids: adhesion and viscosity. Adhesion is defined as the

propensity of dissimilar molecules to get attracted. Viscosity is defined as the

resistance developed within a fluid when subjected to flow. These two properties

produce a combined effect in the turbine for transferring the energy from the air/water

to the rotor or the other way round in the following manner.

As the fluid moves over each disk, the force of adhesion slows down the fluid

molecules just above the disc and thus, they stick on to the surface. The molecules

just above the ones which are glued to the surface slow down when they strike them.

This process continues level by level and thus a chain reaction is initiated. The farther

the distance from the surface, the smaller the effect of adhesion. But the viscous

forces prevent the molecules from separation. This results in a torque being

transmitted to the disk, which imparts rotation to the disk in the direction in which the

fluid interacts with it.

Thus, this thin layer of fluid which imparts torque to the discs by acting on the

boundaries of the fluid-disc contact surface is called boundary layer and the net effect

is called boundary layer effect. The net results of this whole process in that fluid takes

a spiral path from the boundary to the center of the disc, from it exists through the

exhaust holes provided, thereby rotating the discs rapidly.



4.1 MECHANISM

The Tesla turbine is a bladeless centripetal flow turbine. It is referred to as a bladeless

turbine because of its property that fluid impinges on the blade as a same done in the

convectional turbine.

A Tesla turbine consist of a smooth discs with nozzles applying a moving gas to the

edge of the disk by means of viscosity and the adhesion of the surface layer of the gas.

As the gas flows and adds energy to the disks, it spirals into the center exhaust since

the rotor has no projections, it is very sturdy.

Now explaining the detailed mechanism involved in the process of the turbine. Firstly

the main objective of the working of the turbine is to rotate the disk connected to the

shaft .For this to be done. We need air pressure to be applied in tangential direction

with respect to the discs connected to the rotor as well as shaft. The air pressure must

be more than 40 Psi.

For creating the air pressure, we have applied a mechanism consisting of two air-

pumps (used for Exercising) that are fixed on a plyboard which is of 18*18 inch. Set

at the center of the plywood. The air is transferred to a cylinder through T-joint

connected via non-return valves of 10kg/cm2. The air then compressed at 50psi is sent

to the turbine through pneumatic pipe and the flow of the air is controlled by a gate

valve. Compressed air is passed to the turbine through the air inlet nozzle at the top of

the turbine. The air injected through the nozzle passes through the gaps between the

disks creating a boundary layer which results in rotation of the shaft. The shaft then

transfer the power to a dynamo generating electric current which is here used to lit the

LED‟s and also can be used for various purposes.



CHAPTER 5

COMMERCIAL VIABILITY OF THE NEW PROPOSALS

5.1 THE EFFICIENCY FACTOR - Tesla Turbine is more efficient than most of the

prime movers which are currently in use commercially. The following chart shows the

average efficiency of a bladed turbine (Pelton turbine, Kaplan turbine, Francis turbine

etc.), a gas piston, a diesel engine, a fuel cell and a Tesla Turbine.

Thus, if the Tesla turbine is adopted on a commercial basis, the efficiency level of the

process, be it generating current or pumping water, will see a marked improvement

when compared to the current scenario. By adopting the newly proposed fluid and

rotor design, this efficiency is expected to increase even further, thereby pushing the

cause of the Tesla Turbine even further.

5.2 THE COST FACTOR- The following is the comparison between the estimated

cost of the new proposed Tesla turbine and the other machines mentioned earlier.

Here, it can be seen that the expected cost of the proposed Tesla Turbine is not too

high when compared to its peers. This expected cost has been calculated after taking

into account the cost of the laminated composite rotors. The costs of the other

machines are their average market costs. Thus, the Tesla turbine provides an

alternative solution to today‟s energy problems, at a cost which is much lower than

the other commercially wide-spread machines.

5.3 THE SUSTAINABILITY FACTOR - In today‟s world which emphasizes green

technologies, the Tesla turbine is an ideal candidate for future power generation,

water pumping etc. The fact that the properties of adhesion and viscosity combine

together to generate much more power than the power consumed by the compressor

which is used to provide the compressed air to the Tesla Turbine rotor is of much

importance. Even the power consumed by the air heater to heat the air to 80C will be

compensated in the former of a much higher torque generation by the proposed

modified Tesla turbine. Especially in areas such as hydraulic power applications, such

a high torque can play a very significant role.

5.4 CALCULATING THE IDEAL NUMBER OF DISCS - To estimate the total

number of disks for the turbine, assume that at a given internal circumference of the

disk, the flow Reynolds number is less than 2300. Taking the number of disc as

according to our need. Then assuming it to be a number of 8 and proceeding further

operations.

5.5 EFFICIENCY AND CALCULATION - Tesla's time, the efficiency of

conventional turbines was low because the aerodynamic theory needed for effective

blade design did not exist and the low quality of materials available to construct those

blades put severe limitations on operating speeds and temperatures. The efficiency of

a conventional turbine is related to the pressure difference between the intake and the



exhaust. To achieve a higher pressure difference very hot fluids such as superheated

steam are used which is why the availability of higher temperature materials allow

higher efficiencies. If the turbine uses a gas which is liquid at room temperature then

you can use a condenser after the exhaust to increase the pressure difference.

Tesla's design sidestepped the key drawbacks of the bladed turbine. It does suffer

from other problems such as shear losses and flow restrictions. Some of Tesla

turbine's advantages lie in relatively low flow rate applications or when small

applications are called for. The disks need to be as thin as possible at the edges in

order not to introduce turbulence as the fluid leaves the disks. This translates to

needing to increase the number of disks as the flow rate increases. Maximum

efficiency comes in this system when the inter-disk spacing approximates the

thickness of the boundary layer, and since boundary layer thickness is dependent on

viscosity and pressure, the claim that a single design can be used efficiently for a

variety of fuels and fluids is incorrect. A Tesla turbine differs from a conventional

turbine only in the mechanism used for transferring energy to the shaft. Various

analyses demonstrate the flow rate between the disks must be kept relatively low to

maintain efficiency. Reportedly, the efficiency of the Tesla turbine drops with

increased load. Under light load, the spiral taken by the fluid moving from the intake

to the exhaust is a tight spiral, undergoing many rotations. Under load, the number of

rotations drops and the spiral becomes progressively shorter. This will increase the

shear losses and also reduce the efficiency because the gas is in contact with the discs

for less distance.

Efficiency is a function of power output. A light load makes for high efficiency and a

heavy load, which increases the slip in the turbine and lowers the efficiency, though

this is not exclusive to Tesla turbines. The turbine effeciency of the gas Tesla turbine

is estimated to be above 60, reaching a maximum of 95 percent. Keep in mind that

turbine efficiency is different from the cycle efficiency of the engine using the

turbine. Axial turbines which operate today in steam plants or jet engines have

efficiencies of about 60 - 70% (Siemens Turbines Data). This is different from the

cycle efficiencies of the plant or engine which are between approximately 25% and

42%, and are limited by any to fall below the turbine efficiency. Tesla claimed that a

steam version of his device would achieve around 95 percent efficiency. Actual tests

of a Tesla Steam Turbine at the Westinghouse works showed a steam rate of 38

pounds per horsepower hour, corresponding to a turbine efficiency in the range of

20%, while contemporary steam turbines could often achieve turbine efficiencies of

well over 50%. The methods and apparatus for the propulsion of

fluids and thermodynamic transformation of energy were disclosed in various patents.

The thermodynamic efficiency is a measure of how well it performs compared to

an isentropic case. It is the ratio of the ideal to the actual work input/output. This can

be taken to be the ratio of the ideal change in enthalpy to the real enthalpy for the

same change in pressure.



In the 1950s, Warren Rice attempted to re-create Tesla's experiments, but he did

not perform these early tests on a pump built strictly in line with the Tesla's patented

design (it, among other things, was not a Tesla multiple staged turbine nor did it

possess Tesla's nozzle). Rice's experimental single stage system's working fluid was

air. Rice's test turbines, as published in early reports, produced an overall measured

efficiency of 36% to 41% for a single stage. Higher percentages would be expected if

designed as originally proposed by Tesla.

In his final work with the Tesla turbine and published just prior to his retirement, Rice

conducted a bulk-parameter analysis of model laminar flow in multiple disk turbines.

A very high claim for rotor efficiency (as opposed to overall device efficiency) for

this design was published in 1991 entitled "Tesla Turbo machinery". This paper

states:

"With proper use of the analytical results, the rotor efficiency using laminar flow can

be very high, even above 95%. However, in order to attain high rotor efficiency, the

flow rate number must be made small which means high rotor efficiency is achieved

at the expense of using a large number of disks and hence a physically larger rotor."

Modern multiple stage bladed turbines typically reach 60% - 70% efficiency, while

large steam turbines often show turbine efficiency of over 90% in

practice. Volute rotor matched Tesla-type machines of reasonable size with common

fluids (steam, gas, and water) would also be expected to show efficiencies in the

vicinity of 60% - 70% and possibly higher.



CHAPTER 6

UTILITIES

Tesla Turbine is more efficient than most of the prime movers which are currently in

use commercially. The following chart shows the average efficiency of a bladed

turbine (Pelton turbine, Kaplan turbine, Francis turbine etc.), a gas piston, a diesel

engine, a fuel cell and a Tesla Turbine. Thus, if the Tesla turbine is adopted on a

commercial basis, the efficiency level of the process, be it generating current or

pumping water, will see a marked improvement when compared to the current

scenario. By adopting the newly proposed fluid and rotor design, this efficiency is

expected to increase even further, thereby pushing the cause of the Tesla Turbine even

further. In today‟s world which emphasizes green technologies, the Tesla turbine is an

ideal candidate for future power generation, water pumping etc. The fact that the

properties of adhesion and viscosity combine together to generate much more power

than the power consumed by the compressor which is used to provide the compressed

air to the Tesla Turbine rotor is of much importance. Even the power consumed by the

air heater to heat the air to 80C will be compensated in the former of a much higher

torque generation by the proposed modified Tesla turbine. Especially in areas such as

hydraulic power applications, such a high torque can play a very significant role.

6.1 ADVANTAGES

Simple in construction.

Corrosion and cavitation is less.

Pollution free.

Low cost to produce and maintain.

This type of equipment can be operated at a wide range of working medium

parameters without any danger and malfunction.

It is not so sensitive to a partially polluted working medium, since the fluid

flow is parallel to disks, so it can be operated with saturated steam.

This turbine can be adjusted to different circumstances by applying a few

cross section has to be adjusted to the actual demand which is an

interchangeable part of the equipment

It is a bladeless turbine working smoothly by spinning of central disc by

friction from a gas or fluid. Since the turbine itself has no drawback, it is

extremely stable.



6.2 DISADVANTAGES

Low rotor torque.

Often not suitable for a direct replacement for conventional turbines and

pumps, without changes to the machinery it is interacting with.

Proof of its efficiency compared to conventional turbines is still questionable

and needs more research.

It has remained underdeveloped and hence design improvements are still

being made.

Need more changes to the initial design to reach theoretical values.

6.3 APPLICATIONS

Tesla turbine has not seen widespread commercial use since its invention.

The Tesla pump, however, has been commercially available since 1982 and is

used to pump fluids that are abrasive, viscous, contain solids, shear sensitive

or otherwise difficult to handle with other pumps.

Applications of the Tesla turbine as a multiple-disk centrifugal blood pump

have yielded promising results.

Biomedical engineering research on such applications has been continued into

the 21st century.



CHAPTER 7

CONCLUSION AND SCOPE FOR FUTURE WORK

7.1 CONCLUSION

In this project, an effort has been made to push the case of the

commercialization of the Tesla Turbine. Tesla turbine should be considered in

applications in which conventional machines are inadequate. This includes

applications for small shaft power, or the use of very viscous fluid or non-

Newtonian fluids.

Multiple-disk turbine can operate with abrasive two-phase flow mixtures with

less erosion of material from the rotor. For that reason, they should be further

investigated for applications to produce power from geothermal steam and

particle-laden industrial gas flows. There may also be unique applications

possible using ceramic disks.

There is considerable evidence that multiple-disk turbine can be quieter in

operation than is conventional machinery and that the noise produced is more

nearly „„white‟‟ noise without a prevailing sound signature. Multiple-disk

pumps are well known to resist cavitation. It is the only type of turbine that

can be easily constructed in a relatively primitive machine shop.

Although Tesla himself described that the Tesla Turbine was his greatest

invention, it has not found widespread acceptance. It is expected that by

analyzing the reasons for that and suggesting improvements like a new

working fluid and a new rotor material, a small step forward to commercialize

this turbine has been made. The higher torque generation of such a modified

Tesla Turbine is expected to revive its fortunes in the commercial market.

7.2 SCOPE FOR FUTURE WORK

It has been found that the efficiency of the rotor can be very high, at least

equal to that achieved by conventional rotors. But it has proved very difficult

to achieve efficient nozzles in the case of turbines. For pumps and

compressors, efficient diffusion after the rotor has proven difficult to achieve.

As a result, only modest machine efficiencies have been demonstrated.

The ability of the laminated composite material, with which the rotor is to be

constructed, to absorb high stress concentration levels, both thermal and

structural, will prove to be beneficial.



CHAPTER 8

BIBLIOGRAPHY

J. H. Armstrong, “An Investigation of the Performance of a Modified Tesla

Turbine” M.S. Thesis, Georgia Institute of Technology, June (1952).

S. K. P. Young, “The Investigation and Analysis of the Tesla Turbine,” M.S.

Thesis, University of Illinois (1957).

Tesla Turbomachinery by Warren Rice Arizona State University, Tempe,

Arizona, U.S.A.

www.google.com

www.mechmagic.com

www.iitinfo.com

www.wikipedia.com

Dssault‟s System software

Microsoft office

report tesla turbine

Documents

bladeless turbine

radial turbine

tesla turbine rotors

boundary layer turbine

prandtl layer turbine

cohesiontype turbine

new fluid

new working fluid