INTRODUCTION

A heat pipe is a device that efficiently transports thermal energy from its one point to the other. It utilizes the latent heat of the vaporized working fluid instead of the sensible heat. As a result, the effective thermal conductivity may be several orders of magnitudes higher than that of the good solid conductors. A heat pipe consists of a sealed container, a wick structure, a small amount of working fluid that is just sufficient to saturate the wick and it is in equilibrium with its own vapor. The operating pressure inside the heat pipe is the vapor pressure of its working fluid. The length of the heat pipe can be divided into three parts viz. evaporator section, adiabatic section and condenser section. In a standard heat pipe, the inside of the container is lined with a wicking material. Space for the vapor travel is provided inside the container.

Basic components of a heat pipe

The basic components of a heat pipe are
1. The container
2. The working fluid
3. The wick or capillary structure

Container

The function of the container is to isolate the working fluid from the outside environment. It has to be there for leak proof, maintain the pressure differential across the walls, and enable transfer of thermal energy to take place from and into the working fluid.

The prime requirements are:
1. Compatibility (Both with working fluid and External environment)
2. Porosity
3. Wettability
4. Ease of fabrication including welding, machinability and ductility
5. Thermal conductivity
6. Strength to weight ratio

The working fluid

The first consideration in the identification of the working fluid is the operating vapor temperature range. Within the approximate temperature band, several possible working fluids may exist and a variety of characteristics must be examined in order to determine the most acceptable of these fluids for the application considered.

The prime requirements are:
7. Compatibility with wick and wall materials
8. Good thermal stability
9. Wettability of wick and wall materials
10. High latent heat
11. High thermal conductivity
12. Low liquid and vapor viscosities
13. High surface tension

Wick

The wick structure in a heat pipe facilitates liquid return from the evaporator from the condenser. The main purposes of wick are to generate the capillary pressure, and to distribute the liquid around the evaporator section of heat pipe. The commonly used wick structure is a wrapped screen wick.

Download Seminar Report On HEAT PIPE.doc

INTRODUCTION

Since the world’s resources of material and energy are getting progressively, by necessity, there is growing involvement in studies of wear on a global basis. Wear of sliding components result in reduced mechanical efficiency and an irretrievable loss of material in the form of wear debris. Wear at the interface between moving particles is a normal characteristic of machine operation. The kind and rate of wear depend on the machine type. Lubrication is provided between the moving surface to minimize the wear but during operations millions minute wear particles entering the lubricating oil. These particles are in suspension in the oil, larger particles may be trapped by filter while others generally too small to be removed, remain in suspension in the circulating oil.

Condition based monitoring has, in the past, been referred to as an art, when quite clearly it is a science, and despites the cost of machine, surprisingly little attention has been devoted to this science from the viewpoint of understanding and modeling failure mechanisms and the study of probability to failure. Predictive maintenance technique has now become common exercises as they maximize the machine availability time and minimize the cost of maintenance, since the machine can be stopped just before as impending problem in an other wise healthy machine

Fault detection using vibration analysis is difficult in very low speed – high load noisy machines. In the case of slow speed bearing the vibration generated by damaged components is very low, usually close to the floor noise and difficult to identify. In these situations, Wear Debris Analysis has proven useful in providing supporting evidence on the bearing or gear status. It also provides information on the wear mechanism, which is involved.

Sliding adhesive wear particles are found in most lubricating oils. They are an indication of normal wear. They are produced in large numbers when one metal surface moves across another. The particles are seen as thin asymmetrical flakes of metals with highly polished surfaces.

Download Seminar Report On Wear Debris Analysis.doc

ABSTRACT

Brake performance can be divided into two distinct classes:
1) Base brake performance
2) Controlled brake performance.

A base brake event can be described as a normal or typical stop in which the driver maintains the vehicle in its intended direction at a controlled deceleration level that does not closely approach wheel lock. All other braking events where additional intervention may be necessary, such as wheel brake pressure control to prevent lockup, application of a wheel brake to transfer torque across an open differential, or
application of an induced torque to one or two selected wheels to correct an under- or over steering condition, may be classified as controlled brake performance. Statistics from the field indicate the majority of braking events stem from base brake applications and as such can be classified as the single most important function. From this perspective, it can be of interest to compare modern-day Electro-Hydraulic Brake (EHB) hydraulic systems with a conventional vacuum-boosted brake apply system and note the various design options used to achieve performance and reliability
objectives.

INTRODUCTION

What is EHB System?

The next brake concept. This system is a system which senses the driver’s will of braking through the pedal simulator and controls the braking pressures to each wheels. The system is also a hydraulic Brake by Wire system.

Many of the vehicle sub-systems in today’s modern vehicles are being converted into “by-wire” type systems. This normally implies a function, which in the past was activated directly through a purely mechanical device, is now implemented through electro-mechanical means by way of signal transfer to and from an Electronic Control Unit. Optionally, the ECU may apply additional “intelligence” based upon input from other sensors outside of the driver’s influence. Electro-Hydraulic Brake is not a true “by-wire” system with the thought process that the physical wires do not extend all the way to the wheel brakes. However, in the true sense of the definition, any EHB vehicle may be braked with an electrical “joystick” completely independent of the traditional brake pedal. It just so happens that hydraulic fluid is used to transmit energy from the actuator to the wheel brakes. This configuration offers the distinct advantage that the current production wheel brakes may be maintained while an integral, manually applied, hydraulic failsafe backup system may be directly
incorporated in the EHB system. The cost and complexity of this approach typically compares favourably to an Electro-Mechanical Brake (EMB) system, which requires significant investment in vehicle electrical failsafe architecture, with some needing a 42 volt power source. Therefore, EHB may be classified a “stepping stone”
technology to full Electro-Mechanical Brakes.

Download Seminar Report On: ehb.pdf

ABSTRACT

Gasoline direct injection (GDI) engine technology has received considerable attention over the last few years as a way to significantly improve fuel efficiency without making a major shift away from conventional internal combustion technology. In many respects, GDI technology represents a further step in the natural evolution of gasoline engine fueling systems. Each step of this evolution, from mechanically based carburetion, to throttle body fuel injection, through multi-point and finally sequential multi-point fuel injection, has taken advantage of improvements in fuel injector and electronic control technology to achieve incremental gains in the control of internal combustion engines. Further advancements in these technologies, as well as continuing evolutionary advancements in combustion chamber and intake valve design and combustion chamber flow dynamics, have permitted the production of GDI engines for automotive applications. Mitsubishi, Toyota and Nissan all market four- stroke GDI engines in Japan.

Major Objectives of the GDI engine

• Ultra-low fuel consumption that betters that of even diesel engines
• Superior power to conventional MPI engines

Sophisticated high-pressure injectors capable of producing very fine, well-defined fuel sprays, coupled with advanced charge air control techniques, now make stable GDI combustion feasible. There are impediments to widespread GDI introduction, however, especially in compliance with stringent emission standards. This report addresses both the efficiencies inherent in GDI technology and the emissions constraints that must be addressed before GDI can displace current spark-ignition engine technology.

In this seminar I am intending to familiarize the working of this technology, which has the capability to become the turning point in the development of diesel engine technology

WHY NOT CARBURETTOR?

All Internal combustion engines burn fuel in air and every fuel has ideal air ratio at which it will ignite or burn as completely as possible. The challenge that faces engineers is to introduce the perfect or precise proportions of fuel and air required for complete combustion. This is commonly referred to as the stoichiometric ratio. Petrol has a stoichiometric ratio of 14.7:1(14.7 parts of air with 1 part of fuel by weight). This ratio has to be maintained under the varying engine loads and conditions. The carb earlier did this metering with its ancillaries. But the carb has its limits and though performance and economy with modern carbs were acceptable, a seamless power delivery and emissions often suffered.

Carburetor has following disadvantages

• Vapour lock
• Perfect air/fuel mixture cannot be obtained
• Lack of throttle response
• Low volumetric efficiency
• Icing – problem in aircraft engines
• Mechanical device
• Compromises on emission
Download Seminar Report On :GDI-Gasoline Direct Injection.doc

ABSTRACT

A laser-based contact less displacement measurement system is used for data acquisition to analyze the mechanical vibrations exhibited by vibrating structures and machines. The analysis of these vibrations requires a number of signal processing operations which include the determination of the system conditions through a classification of various observed vibration signatures and the detection of changes in the vibration signature in order to identify possible trends. This information is also combined with the physical characteristics and contextual data (operating mode, etc.) of the system under surveillance to allow the evaluation of certain characteristics like fatigue, abnormal stress, life span, etc., resulting in a high level classification of mechanical behaviors and structural faults according to the type of application.

Smart sensors or latest generation sensors are now use for vibration measurements. Where the first generation sensors are piezoelectric accelerometers, second generation sensors are modification of piezoelectric accelerometers and latest are the smart sensors. Third-generation smart sensors use mixed mode analogue and digital operations to perform simple unidirectional communication with the condition monitoring equipment.

INTRODUCTION

The study of vibrations generated by mechanical structures and electrical machines are very important. The advent of machines and processes that are more and more complex and the ever increasing exploitation and production costs have favored the emergence of several application fields requiring vibration analysis. Among these application fields, we find machine monitoring, modal analysis, quality control, and environment tests. These functions are used in fields such as aeronautics, space industry, automotive industry, energy production, civil engineering, and audio equipment.

The signal processing application described here uses a laser-based vibrometer in order to analyze the vibrations exhibited by mechanical systems. This technique can be used in the numerous applications mentioned above. The problem is to develop an intelligent system that has the ability to determine the system conditions based on a classification of the possible vibration signatures, detect changes in the vibration signature, and analyze their trends.

The classification of the various possible vibration signatures requires a priori knowledge of the mechanical system under healthy conditions as well as for the various fault conditions; when possible a mathematical model of the system should be provided. The latter is often crucial for the good interpretation of the observations, since it predicts the dynamic behavior of the structure and thus the healthy vibration signature.

Vibration spectra are in general “peaky” due to either the periodic nature of the system’s excitation or to the natural resonance properties of the mechanical system. Changes in a vibration signal can result from a variation of the amplitude, frequency, and/or phase of one or many of the components. Moreover, new peaks may add to the existing spectrum, or some peaks may fade out. Changes can also appear in the form of short transients or spikes in the time domain. At the extreme, if the vibrations become so strong that the structure actually starts to move, then the overall average level of vibration would change, that is, a DC component would appear.

All of the above changes may occur gradually, like fatigue stress slowly deteriorating the material’s properties, or they may occur suddenly, like the rupture of a mechanical part within a machine. They may also occur periodically or in a random fashion depending on the process generating the vibrations. For multiple state systems, changes must be interpreted carefully. For example, if the operating speed of a rotating machine is raised from A to B, the vibration analysis system should not declare the observed changes as being the result of a mechanical failure, but should adapt itself to this new mode of operation.

Download Seminar Report On Mechanical Vibration Analysis.doc

ABSTRACT

Surface plasmon resonance (SPR) is a phenomenon occurring at metal surfaces(typically gold and silver) when an incident light beam strikes the surface at a particular angle.Depending on the thickness of a molecular layer at the metal surface,the SPR phenomenon results in a graded reduction in intensity of the reflected light.Biomedical applications take advantage of the exquisite sensitivity of SPR to the refractive index of the medium next to the metal surface, which makes it possible to measure accurately the adsorption of molecules on the metal surface an their eventual interactions with specific ligands. The last ten years have seen a tremendous development of SPR use in biomedical applications.

The technique is applied not only to the measurement in real time of the kinetics of ligands receptor interactions and to the screening of lead compounds in the pharmaceutical industry, but also to the measurement DNA hybridization, enzyme- substrate interactions, in polyclonal antibody characterization, epitope mapping, protein conformation studies and label free immunoassays. Conventional SPR is applied in specialized biosensing instruments. These instruments use expensive sensor chips of limited reuse capacity and require complex chemistry for ligand or protein immobilization. Laboratory has successfully applied SPR with colloidal gold particles in buffered solutions. This application offers many advantages over conventional SPR. The support is cheap, easily synthesized, and can be coated with various proteins or protein ligand complexes by charge adsorption. With colloidal gold, the SPR phenomenon can be monitored in any UV spectrophotometer. For high throughput applications we have adapted the technology in an automated clinical chemistry analyzer. This simple technology finds application in label free quantitative immunoassay techniques for proteins and small analytes, in conformational studies with proteins as well as real time association dissociation measurements of receptor ligand interactions for high throughput screening and lead optimization.

INTRODUCTION

During the last two decades we have witnessed remarkable research and development activity aimed at the realization of optical sensors for the measurement of chemical and biological quantities. First optical chemical sensors were based on the measurement of changes in absorption spectrum and were developed for the measurement of CO2 and O2 concentration. Since then a large variety of optical methods have been used in chemical sensors and biosensors including elipsometry, spectroscopy, interferometry spectroscopy of guided modes in optical wave guide structures and surface plasmon resonance .

The potential of surface plasmon resonance for characterization of thin films and monitoring process at metal interfaces was recognized in the late seventies. In 1982 the use of SPR for gas detection and biosensing was demonstrated by Nylander and lieberg . Since then SPR sensing has been receiving continuously growing attention from scientific community. Development of new SPR sensing configurations as well as applications of SPR sensing devices for the measurement of physical , chemical and biological quantities have been described . The SPR sensor technology has been commercialized by several companies and become a leading technology in the field of direct real time observation of the biomolecular interaction.
The phenomenon of anomalous diffraction on diffraction gratings due to the excitation of surface plasma waves was first described in the beginning of the twentieth century by Wood. In the late sixties, optical excitation of surface plasmons by the method of attenuated total reflection was demonstrated by Kretschmann and Otto .

Download Seminar Report On SURFACE PLASMON RESONANCE.doc

ABSTRACT

In this era of increasing fuel prices, here a device called ‘FUEL ENERGIZER’ help us to Reduce Petrol /Diesel /Cooking gas consumption up to 28%, or in other words this would equal to buying the fuel up to 28% cheaper prices.When fuel flow through powerful magnetic field created by Magnetizer Fuel Energizer, The hydrocarbons change their orientation and molecules in them change their configuration. Result: Molecules get realigned, and actively into locked with oxygen during combustion to produce a near complete burning of fuel in combustion chamber.

INTRODUCTION

Today’s hydrocarbon fuels leave a natural deposit of carbon residue that clogs carburetor, fuel injector, leading to reduced efficiency and wasted fuel. Pinging, stalling, loss of horsepower and greatly decreased mileage on cars are very noticeable. The same is true of home heating units where improper combustion wasted fuel (gas) and cost, money in poor efficiency and repairs due to build-up.

Most fuels for internal combustion engine are liquid, fuels do not combust until they are vaporized and mixed with air. Most emission motor vehicle consists of unburned hydrocarbons, carbon monoxide and
oxides of nitrogen. Unburned hydrocarbon and oxides of nitrogen react in the atmosphere and create smog. Smog is prime cause of eye and throat irritation, noxious smell, plat damage and decreased visibility. Oxides of nitrogen are also toxic.

Generally fuels for internal combustion engine is compound of molecules. Each molecule consists of a number of atoms made up of
number of nucleus and electrons, which orbit their nucleus. Magnetic movements already exist in their molecules and they therefore already have positive and negative electrical charges. However these molecules have not been realigned, the fuel is not actively inter locked with oxygen during combustion, the fuel molecule or hydrocarbon chains must be ionized and realigned. The ionization and realignment is achieved through the application of magnetic field created by ‘Fuel Energizer’

Download seminar Topic on: FUEL – ENERGIZER.pdf

Diesel engines play a vital role in modern life , but it causes problems like pollution. One solution to avoid the ewin problem of environmental pollution and energy shortage will be a carefully planned gradual shift of our economy from fossil fuels to renewable sources of energy. These renewable sources of energy is mainly contributed by fuels of bio-origin.

The fuels of bio-origin may be alcohol,editable and non editable vegetable oils, biomass, biogas etc. Some of these fuels can be used directly while the others need to be formulated to bring the relevant properties close to conventional fuels. Methanol and ethanol are two accepted alternative fuels, which posses the potential to be produced from bio mass resources. But they are not well suited to be used in diesel engines. In the case of alcohol it produces aldehydes and ketones in their exhaust, which creates associated environmental and health problems.

The main alternative fuel in the present is bio-diesel. It is the name of clean burning monoalkyl esters basedoxygenated fue, produced form vegetable oil. These fules contain no petroleum but can be blended at any level with petroleum diesel to create bio diesel blend. It can be used in the compression ignition engine without any major modification. It is simple to use, biodegradable, non toxic and essentially free of sulphur and aromatic compounds. Biodiesel is renewable and can be produced from agricultural and farm resources.The molecular structure of vegetable oil is similar to that of diesel, but it contains additional oxygen which reduces soot.

Though it has lot of advantages the use of vegetable oil as fuel face many problems.Viscosity of vegetable oil is very high, which influences the shape of fuel spray. High viscosity causes poor atomization, large droplets and high spray jet penetration. With high viscosities the jet tends to be a solid stream instead of a spray of droplets. As a result proper mixing of fuel doesn’t occur. This results in poor combustion resulting in loss of power and economy.

The problems with use of biodiesel can be divided as :

1) Engine modifications.
- Duel fuelling
- Injection system modification
- Heated fuel lines.
2) Fuel modifications.
- Blending
- Transesterification
- Cracking/pyrolysis
- Hydrogenation to reduce polymerization

The advantages of biodiesel are

Decrease in the smoke density and NOx to a level lower than the baseline diesel engine.
Improvement in brake thermal efficiency.
Flash and fire points are comparatively higher for esters, thus reducing fire hazards.
Higher injection pressure.
Engine shows better performance for blends with diesel rather than pure ester.
Cost of bio diesel production is comparatively more than diesel but it can be reduced by mass production.

ABSTRACT

Air muscle is essentially a robotic actuator which is replacing the conventional pneumatic cylinders at a rapid pace. Due to their low production costs and very high power to weight ratio, as high as 400:1, the preference for Air Muscles is increasing. Air Muscles find huge applications in bio robotics and development of fully functional prosthetic limbs, having superior controlling as well as functional capabilities compared with the current models. This paper discusses Air Muscles in general, their construction, and principle of operation, operational characteristics and applications.

INTRODUCTION

Robotic actuators conventionally are pneumatic or hydraulic devices. They have many inherent disadvantages like low operational flexibility, high safety requirements, and high cost operational as well as constructional etc. The search for an actuator which would satisfy all these requirements ended in Air Muscles. They are easy to manufacture, low cost and can be integrated with human operations without any large scale safety requirements. Further more they offer extremely high power to weight ratio of about 400:1. As a comparison electric motors only offer a power ration of 16:1. Air Muscles are also called McKibben actuators named after the researcher who developed it.

History

It was in 1958 that R.H.Gaylord invented a pneumatic actuator which’s original applications included a door opening arrangement and an industrial hoist. Later in 1959 Joseph.L.McKibben developed Air Muscles. The source of inspiration was the human muscle itself, which would swell when a force has to be applied. They were developed for use as an orthotic appliance for polio patients. Clinical trials were realized in 1960s. These muscles were actually made from pure rubber latex, covered by a double helical weave (braid) which would contract when expanded radially. This could actually be considered as a biorobotic actuator as it operates almost similar to a biological muscle.

Air Muscle Schematic- McKibben Model

The current form air muscles were developed by the Bridgestone Company, famous for its tires. The primary material was rubber i.e. the inner tube was made from rubber. Hence these actuators were called ‘Rubbertuators’. These developments took place around 1980s.Later in 1990s Shadow Robotic Company of the United Kingdom began developing Air Muscles. These are the most commonly used air muscles now and are associated with almost all humanoid robotic applications which were developed recently. Apart from Shadow another company called The Merlin Humaniform develops air muscles for the same applications, although their design is somewhat different from the Shadow muscles.

Download Seminar Report On Air Muscles.doc