1). Memorizing - this is absolutely the worst way to keep track of material. People are preoccupied with trying to remember the words to say and not the ideas behind the words (or with the audience). As a result, normal voice inflection disappears. With memorizing, mental blocks become inevitable. With memorizing it is not a matter of "will" you forget; it's a matter of WHEN!
2). Reading from complete text - Listening to someone read a speech or presentation is hated by most people. People say, "If that's all they were going to do is read their speech, I could have read it myself." I'm sure many of us have experienced this at least once while attending a conference or two. Below are some reasons why I believe people read poorly:
3). Using Notes - This is the most common way for remembering material. Using notes is better than reading since the speaker can have normal voice inflection and make more effective eye contact. If your notes are on the lectern, you probably won't move very far from them. If notes are in your hand, you probably won't gesture very much.
4).Using Visual Aids As Notes - Simple visual aids can effectively serve as headings and subheadings. Speak to the heading. Say what you want to say and move on. If you forget something, that's okay; the audience will never know unless you tell them.
Practice creating just a few meaningful headings to use and practice using only these headings as your "cues". This will take practice, but practicing using only these few words will force you to better internalize your speech.
Monday, October 19, 2009
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Micro-electro Mechanical Systems
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Definition
Micro-electromechanical systems (MEMS) is a technology that combines computers with tiny mechanical devices such as sensors, valves, gears, mirrors, and actuators embedded in semiconductor chips.
Overview
MEMS are already used as accelerometers in automobile air-bags. They've replaced a less reliable device at lower cost and show promise of being able to inflate a bag not only on the basis of sensed deceleration but also on the basis of the size of the person they are protecting. Basically, a MEMS device contains micro-circuitry on a tiny silicon chip into which some mechanical device such as a mirror or a sensor has been manufactured. Potentially, such chips can be built in large quantities at low cost, making them cost-effective for many uses.
Introduction
Among the presently available uses of MEMS or those under study are:
Global position system sensors that can be included with courier parcels for constant tracking and that can also sense parcel treatment en route .
Sensors built into the fabric of an airplane wing so that it can sense and react to air flow by changing the wing surface resistance; effectively creating a myriad of tiny wing flaps .
Optical switching devices that can switch light signals over different paths at 20-nanosecond switching speeds
Sensor-driven heating and cooling systems that dramatically improve energy savings .
Building supports with imbedded sensors that can alter the flexibility properties of a material based on atmospheric stress sensing .
Micro-electromechanical systems (MEMS) is a technology that combines computers with tiny mechanical devices such as sensors, valves, gears, mirrors, and actuators embedded in semiconductor chips.
Overview
MEMS are already used as accelerometers in automobile air-bags. They've replaced a less reliable device at lower cost and show promise of being able to inflate a bag not only on the basis of sensed deceleration but also on the basis of the size of the person they are protecting. Basically, a MEMS device contains micro-circuitry on a tiny silicon chip into which some mechanical device such as a mirror or a sensor has been manufactured. Potentially, such chips can be built in large quantities at low cost, making them cost-effective for many uses.
Introduction
Among the presently available uses of MEMS or those under study are:
Global position system sensors that can be included with courier parcels for constant tracking and that can also sense parcel treatment en route .
Sensors built into the fabric of an airplane wing so that it can sense and react to air flow by changing the wing surface resistance; effectively creating a myriad of tiny wing flaps .
Optical switching devices that can switch light signals over different paths at 20-nanosecond switching speeds
Sensor-driven heating and cooling systems that dramatically improve energy savings .
Building supports with imbedded sensors that can alter the flexibility properties of a material based on atmospheric stress sensing .
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CAMM Systems (breif discription)
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Definition
In an industry, cost of unscheduled stoppage of an equipment is very high, in terms of loss of production and money. Maintenance is an activity carried out to avoid unscheduled stoppages and breakdowns of the equipment, to improve availability and life of plant and machineries, thereby improving the performance of the industry. The effectiveness of production is highly dependent on quality of maintenance. One of the key factor for the success of an industry is an effective maintenance management system.
Proper maintenance management can improve existing capacity utilization rather than going in for additional capacities to meet the ever increasing demand of a large number of products and services.
Maintenance is only viewed as a repair function, however it is a combination of any actions carried out to retain an item in or restore it to an acceptance condition.
The principal objectives of maintenance activity are:
1. To maximise the availability and reliability of all assets (equipment, machinery)
2. To extend the useful life of assets by minimising wear and tear and deterioration.
3. To ensure operation readiness of all equipments required for emergency use at all times.
4. To ensure the safety of personnel/using facility.
The availability (A) of a plant can be defined as:
A = Tup / Tup + Tdown
Where,
Tup = The cumulative time of operation in the normal working state
T down = The cumulative downtime.
Reliability - The probability that a unit will function normally when used according to specified conditions for at least a stated period of time.
Maintainabilty - The probability that a failed unit is put back to satisfactory, operable condition in a given down time.
In a changing world of competition the survival of industries depends on quick decision making and effective management of maintenance function. To accomplish the above objective presently "Computer Aided Maintenance Management Software Packages" are available for the maintenance managers.
CAMM System is a reliable tool available to plan effectively complete tasks on schedule and make quick reviews. This can also be treated as part of "ERP" software.
Typical CAMM system provides:
" Decision support for equipment
" Reliability management
" Real time data capture for condition monitoring of equipment
" Work orders management
" Planning spares requirements
" Planning maintenance budgets
" Monitoring of labour productivity
" Comprehensive equipment databases
" Automatic sequencing of inspections
A typical planned maintenance package consists of three modules:
1. Maintenance administration and control
2. Equipment
3. Maintenance operations
In an industry, cost of unscheduled stoppage of an equipment is very high, in terms of loss of production and money. Maintenance is an activity carried out to avoid unscheduled stoppages and breakdowns of the equipment, to improve availability and life of plant and machineries, thereby improving the performance of the industry. The effectiveness of production is highly dependent on quality of maintenance. One of the key factor for the success of an industry is an effective maintenance management system.
Proper maintenance management can improve existing capacity utilization rather than going in for additional capacities to meet the ever increasing demand of a large number of products and services.
Maintenance is only viewed as a repair function, however it is a combination of any actions carried out to retain an item in or restore it to an acceptance condition.
The principal objectives of maintenance activity are:
1. To maximise the availability and reliability of all assets (equipment, machinery)
2. To extend the useful life of assets by minimising wear and tear and deterioration.
3. To ensure operation readiness of all equipments required for emergency use at all times.
4. To ensure the safety of personnel/using facility.
The availability (A) of a plant can be defined as:
A = Tup / Tup + Tdown
Where,
Tup = The cumulative time of operation in the normal working state
T down = The cumulative downtime.
Reliability - The probability that a unit will function normally when used according to specified conditions for at least a stated period of time.
Maintainabilty - The probability that a failed unit is put back to satisfactory, operable condition in a given down time.
In a changing world of competition the survival of industries depends on quick decision making and effective management of maintenance function. To accomplish the above objective presently "Computer Aided Maintenance Management Software Packages" are available for the maintenance managers.
CAMM System is a reliable tool available to plan effectively complete tasks on schedule and make quick reviews. This can also be treated as part of "ERP" software.
Typical CAMM system provides:
" Decision support for equipment
" Reliability management
" Real time data capture for condition monitoring of equipment
" Work orders management
" Planning spares requirements
" Planning maintenance budgets
" Monitoring of labour productivity
" Comprehensive equipment databases
" Automatic sequencing of inspections
A typical planned maintenance package consists of three modules:
1. Maintenance administration and control
2. Equipment
3. Maintenance operations
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Apache Helicopter (breif discription)
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Definition
The Apache Helicopter is a revolutionary development in the history of war. It is essentially a flying tank- a helicopter designed to survive heavy attack and inflict massive damage. It can zero in on specific targets, day or night, even in terrible weather. As you might expect, it is a terrifying machine to ground forces.
In this topic, we look at the Apache's amazing flight systems, engines, weapon systems, sensor systems and armour systems. Individually these components are remarkable pieces of technology. Combined together they make up an unbelievable fighting machine - the most lethal helicopter ever created.
HISTORY
The first series of Apaches, developed by Hughes Helicopters in the 1970s, went into active service in 1985. The U.S military is gradually replacing this original design, known as the AH-64A Apache, with the more advanced AH-64D Apache Longbow. In 1984, Mc Donnell Douglas purchased Hughes Helicopters, and in 1997, Boeing manufactures Apache helicopters, and the UK-based GKN Westland helicopters manufacturers the English versions of the Apache, the WAH-64.
DRAG: Drag is an aerodynamic force that resists the motion of an object moving through a fluid. The amount of drag depends on a few factors, such as the size of the object, the speed of the car and the density of the air.
THRUST: Thrust is an aerodynamic force that must be created by an airplane in order to overcome the drag. Airplanes create thrust using propellers, jet engines or rockets.
WEIGHT: This is the force acting downwards or the gravitational force.
LIFT: Lift is the aerodynamic force that holds an airplane in the air, and is probably the important of the four aerodynamic forces. Lift is created by the wings of the airplane.
Lift is a force on a wing immersed in a moving fluid, and it acts perpendicular to the flow of the fluid but drag is the same thing, but acts parallel to the direction of the fluid flow.
1. Air approaching the top surface of the wing is compressed into the air above it as it moves upward. Then, as the top surface curves downward and away from the air stream, a low pressure area is developed and the air above is pulled downward toward the back of the wing.
2. Air approaching the bottom surface of the wing is slowed, compressed and redirected in a downward path. As the air nears the rear of the wing, its sped and pressure gradually match that of the air coming over the top. The overall pressure effects encountered on the bottom of the wing are generally less pronounced than those on the top of the wing.
3.1 FOR STRAIGHT AND LEVEL FLIGHT
The following relationships must be true:
THRUST = DRAG
WEIGHT = LIFT
If for any reason, the amount of drag becomes larger then the amount of thrust, the plane will slow down. If the thrust is increased so that it is greater than drag, the plane will speed up.
If the amount of lift drops below the weight of the airplane, the plane will descend. By increasing the lift, the pilot can make the airplane climb
The Apache Helicopter is a revolutionary development in the history of war. It is essentially a flying tank- a helicopter designed to survive heavy attack and inflict massive damage. It can zero in on specific targets, day or night, even in terrible weather. As you might expect, it is a terrifying machine to ground forces.
In this topic, we look at the Apache's amazing flight systems, engines, weapon systems, sensor systems and armour systems. Individually these components are remarkable pieces of technology. Combined together they make up an unbelievable fighting machine - the most lethal helicopter ever created.
HISTORY
The first series of Apaches, developed by Hughes Helicopters in the 1970s, went into active service in 1985. The U.S military is gradually replacing this original design, known as the AH-64A Apache, with the more advanced AH-64D Apache Longbow. In 1984, Mc Donnell Douglas purchased Hughes Helicopters, and in 1997, Boeing manufactures Apache helicopters, and the UK-based GKN Westland helicopters manufacturers the English versions of the Apache, the WAH-64.
DRAG: Drag is an aerodynamic force that resists the motion of an object moving through a fluid. The amount of drag depends on a few factors, such as the size of the object, the speed of the car and the density of the air.
THRUST: Thrust is an aerodynamic force that must be created by an airplane in order to overcome the drag. Airplanes create thrust using propellers, jet engines or rockets.
WEIGHT: This is the force acting downwards or the gravitational force.
LIFT: Lift is the aerodynamic force that holds an airplane in the air, and is probably the important of the four aerodynamic forces. Lift is created by the wings of the airplane.
Lift is a force on a wing immersed in a moving fluid, and it acts perpendicular to the flow of the fluid but drag is the same thing, but acts parallel to the direction of the fluid flow.
1. Air approaching the top surface of the wing is compressed into the air above it as it moves upward. Then, as the top surface curves downward and away from the air stream, a low pressure area is developed and the air above is pulled downward toward the back of the wing.
2. Air approaching the bottom surface of the wing is slowed, compressed and redirected in a downward path. As the air nears the rear of the wing, its sped and pressure gradually match that of the air coming over the top. The overall pressure effects encountered on the bottom of the wing are generally less pronounced than those on the top of the wing.
3.1 FOR STRAIGHT AND LEVEL FLIGHT
The following relationships must be true:
THRUST = DRAG
WEIGHT = LIFT
If for any reason, the amount of drag becomes larger then the amount of thrust, the plane will slow down. If the thrust is increased so that it is greater than drag, the plane will speed up.
If the amount of lift drops below the weight of the airplane, the plane will descend. By increasing the lift, the pilot can make the airplane climb
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(Dyna-cam engine) (breif discription)
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Definition
The original engine is patented and the Company has now made patent applications and received patent pending status for additional features that have been refined. Activity and contacts from the website indicate that there are a lot of buyers for this new engine technology.
The first production engine has been assembled and completed initial testing. The Company has had to design and build a custom dynamometer on which to complete engine testing. After testing has been completed on the first engine, it was installed in an aircraft like a Cessna 182 or a Piper Cherokee that will be able to demonstrate the engine's performance capability
Additional installations are being discussed with owners of several experimental homebuilt aircraft, including, a LancAir, an RV6, a custom designed pusher fashioned after the Long Easy, a new designed homebuilt called the Atlantica, and several others, including a Sea Bee, a Seawind homebuilt, and possibly a Cessna 185. The initial Dyna-Cam Engine to be manufactured and sold is rated at 200 HP. The engine is 13" in diameter, 40" long and weighs 300 pounds with basic accessories. It has unique features and major benefits over conventional engines of similar weight and power.The benefits include lower manufacturing costs in equal production, 50% smaller size, 50% fewer replacement parts, better fuel economy, smoother operation, lighter weight, plus nearly 100% higher torque enabling the engine to turn high efficiency propellers with lower noise output.
DESIGN OVERVIEW
The engine has two identical cylindrical blocks that each have six cylinders arranged parallel around the main shaft located in the center. Cylinders of both blocks line up so that six double-ended pistons can fire back and forth between the aligned cylinders of each block Each free floating piston is cut away on the central interior side and fits with precision around a 9" diameter, four lobe, sinusoidal cam that is keyed to the main shaft.
As the pistons fire back and forth, the main cam rolls through the pistons causing the central shaft to turn. All moving surfaces are roller bearing surfaces. Another smaller 5" cam is attached to the main shaft at the outer end of each block. As each valve cam turns, it pushes against hydraulic lifters which push against the poppet valves inside each cylinder head. The engine is a 4-stroke engine. Because of the design of the main cam, each of the twelve cylinders fires with every revolution of the shaft, in contrast to three times with conventional six-cylinder engines. The engine can be described as a free piston, axially cam-drive engine.
External accessory systems manage air intake, fuel, oil flow, cooling and exhaust. All accessory systems operate similar to standard systems used on conventional engines and may be easily updated with the latest state-of-the-art technology. Devices used on normal piston engines can be adapted to the Dyna-Cam Engine for achieving the lowest possible emissions or higher power output, i.e. electronic ignition, state of the art emissions devices, or high tech fuel injection. Higher torque at lower RPMs and reduced internal friction allow more work to be accomplished by the Dyna-Cam for the same measured quantity of fuel when compared to the conventional piston engine.
The functional and operational design of the Dyna-Cam Engine is complete. Forty prototype units have been tested and rebuilt resulting in the final design that was certified. Minor changes have been completed to expedite assembly and facilitate cost effective mass production. The first engines are now in production and purchase orders and down payments are being taken
The original engine is patented and the Company has now made patent applications and received patent pending status for additional features that have been refined. Activity and contacts from the website indicate that there are a lot of buyers for this new engine technology.
The first production engine has been assembled and completed initial testing. The Company has had to design and build a custom dynamometer on which to complete engine testing. After testing has been completed on the first engine, it was installed in an aircraft like a Cessna 182 or a Piper Cherokee that will be able to demonstrate the engine's performance capability
Additional installations are being discussed with owners of several experimental homebuilt aircraft, including, a LancAir, an RV6, a custom designed pusher fashioned after the Long Easy, a new designed homebuilt called the Atlantica, and several others, including a Sea Bee, a Seawind homebuilt, and possibly a Cessna 185. The initial Dyna-Cam Engine to be manufactured and sold is rated at 200 HP. The engine is 13" in diameter, 40" long and weighs 300 pounds with basic accessories. It has unique features and major benefits over conventional engines of similar weight and power.The benefits include lower manufacturing costs in equal production, 50% smaller size, 50% fewer replacement parts, better fuel economy, smoother operation, lighter weight, plus nearly 100% higher torque enabling the engine to turn high efficiency propellers with lower noise output.
DESIGN OVERVIEW
The engine has two identical cylindrical blocks that each have six cylinders arranged parallel around the main shaft located in the center. Cylinders of both blocks line up so that six double-ended pistons can fire back and forth between the aligned cylinders of each block Each free floating piston is cut away on the central interior side and fits with precision around a 9" diameter, four lobe, sinusoidal cam that is keyed to the main shaft.
As the pistons fire back and forth, the main cam rolls through the pistons causing the central shaft to turn. All moving surfaces are roller bearing surfaces. Another smaller 5" cam is attached to the main shaft at the outer end of each block. As each valve cam turns, it pushes against hydraulic lifters which push against the poppet valves inside each cylinder head. The engine is a 4-stroke engine. Because of the design of the main cam, each of the twelve cylinders fires with every revolution of the shaft, in contrast to three times with conventional six-cylinder engines. The engine can be described as a free piston, axially cam-drive engine.
External accessory systems manage air intake, fuel, oil flow, cooling and exhaust. All accessory systems operate similar to standard systems used on conventional engines and may be easily updated with the latest state-of-the-art technology. Devices used on normal piston engines can be adapted to the Dyna-Cam Engine for achieving the lowest possible emissions or higher power output, i.e. electronic ignition, state of the art emissions devices, or high tech fuel injection. Higher torque at lower RPMs and reduced internal friction allow more work to be accomplished by the Dyna-Cam for the same measured quantity of fuel when compared to the conventional piston engine.
The functional and operational design of the Dyna-Cam Engine is complete. Forty prototype units have been tested and rebuilt resulting in the final design that was certified. Minor changes have been completed to expedite assembly and facilitate cost effective mass production. The first engines are now in production and purchase orders and down payments are being taken
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Cylinder deactivation (breif discription)
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Definition
With alternatives to petrol engine being announced ever so often, we could be forgiven for thinking that the old favorite, the petrol engine, is on its last legs. But nothing could be further from the truth and the possibilities for developing the petrol engine are endless.
One of the most crucial jobs on the agenda is to find ways of reducing fuel consumptions, cutting emissions of the green house gas, co2, and also the toxic emissions which threaten air quality. One such fast emerging technology is cylinder deactivation.
CYLINDER DEACTIVATION
2.1 CONSIDERING DAIMLER CHRYSLER
By considering Daimler Chrysler's new 300cc car's powered by a revival of one of the greatest muscle car engine of all time, the V8 Hemi. This third generation grand master of funk has a capacity of 5.7litres snorts out 340 bhp with 54kgm torque and like all Hemis since the early 1950's has a pushrod valve train rather than a over head cam setup. But even though this Hemi can match its forebears on power 'its thirst for fuel has been cut by 10 to 20%. It is done by Chrysler's new multi displacement system (mds).
When using a lot of power, such as during acceleration, the hemi fires on all eight cylinders as usual. But around town or when cruising -even at motor way speeds or under gentle acceleration-the engine switches to frugal four cylinder mode.
Multi displacement system (mds) is activated at part throttle between 1000 rpm and 3000 rpm, when a hydraulically actuated catch in the special valve lifters trips to prevent the valves from opening. Hot gases are trapped in four of the eight cylinders, compressing and expanding like giant air springs as the engine turns over and keeping the cylinder warm. But as long as the valves remain closed, only four cylinders consume fuel instead of eight.
Engine efficiency is also improved because the four dormant cylinders are no longer working hard at sucking air into the engine, something that consumes a substantial amount of power. Although the average fuel saving is 10% ,under certain conditions it is a huge 20%.The transition from eight cylinders to four cylinders happens in just 40 mille seconds under the control of sophisticated engine management software which controls not just the multidisplacement system but also a drive-by-wire throttle.
CONSIDERING HONDA
IN Japan the 3.0 liter I-VTEC (intelligent VTEC) V6 of the Honda inspire can also deactivate tree of its first cylinders refinement being guaranteed by active hydraulic engine mounts to cancel out any vibration and active noise control with in the cabin to neutralize any unwanted booming. Honda's CIVIC IMA hybrid also make use of V TEC to deactivate three cylinders on the over run-again to reduce the pumping losses and cut fuel consumption
CONSIDERING GENERAL MOTORS
The actual idea of cylinder deactivation is not new. General Motors tried it in 1981 with the V-8-6-4 engine but through lack of sophisticated electronics drivability was awful. Now GM is returning to the idea again and is to soon launch Displacement on Demand (DOD} on itsVortecV 8's improving consumption by between 6 and 8%.
With alternatives to petrol engine being announced ever so often, we could be forgiven for thinking that the old favorite, the petrol engine, is on its last legs. But nothing could be further from the truth and the possibilities for developing the petrol engine are endless.
One of the most crucial jobs on the agenda is to find ways of reducing fuel consumptions, cutting emissions of the green house gas, co2, and also the toxic emissions which threaten air quality. One such fast emerging technology is cylinder deactivation.
CYLINDER DEACTIVATION
2.1 CONSIDERING DAIMLER CHRYSLER
By considering Daimler Chrysler's new 300cc car's powered by a revival of one of the greatest muscle car engine of all time, the V8 Hemi. This third generation grand master of funk has a capacity of 5.7litres snorts out 340 bhp with 54kgm torque and like all Hemis since the early 1950's has a pushrod valve train rather than a over head cam setup. But even though this Hemi can match its forebears on power 'its thirst for fuel has been cut by 10 to 20%. It is done by Chrysler's new multi displacement system (mds).
When using a lot of power, such as during acceleration, the hemi fires on all eight cylinders as usual. But around town or when cruising -even at motor way speeds or under gentle acceleration-the engine switches to frugal four cylinder mode.
Multi displacement system (mds) is activated at part throttle between 1000 rpm and 3000 rpm, when a hydraulically actuated catch in the special valve lifters trips to prevent the valves from opening. Hot gases are trapped in four of the eight cylinders, compressing and expanding like giant air springs as the engine turns over and keeping the cylinder warm. But as long as the valves remain closed, only four cylinders consume fuel instead of eight.
Engine efficiency is also improved because the four dormant cylinders are no longer working hard at sucking air into the engine, something that consumes a substantial amount of power. Although the average fuel saving is 10% ,under certain conditions it is a huge 20%.The transition from eight cylinders to four cylinders happens in just 40 mille seconds under the control of sophisticated engine management software which controls not just the multidisplacement system but also a drive-by-wire throttle.
CONSIDERING HONDA
IN Japan the 3.0 liter I-VTEC (intelligent VTEC) V6 of the Honda inspire can also deactivate tree of its first cylinders refinement being guaranteed by active hydraulic engine mounts to cancel out any vibration and active noise control with in the cabin to neutralize any unwanted booming. Honda's CIVIC IMA hybrid also make use of V TEC to deactivate three cylinders on the over run-again to reduce the pumping losses and cut fuel consumption
CONSIDERING GENERAL MOTORS
The actual idea of cylinder deactivation is not new. General Motors tried it in 1981 with the V-8-6-4 engine but through lack of sophisticated electronics drivability was awful. Now GM is returning to the idea again and is to soon launch Displacement on Demand (DOD} on itsVortecV 8's improving consumption by between 6 and 8%.
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Cryocar (breif discription)
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Definition
Cryogens are effective thermal storage media which, when used for automotive purposes, offer significant advantages over current and proposed electrochemical battery technologies, both in performance and economy. An automotive propulsion concept is presented which utilizes liquid nitrogen as the working fluid for an open Rankine cycle. The principle of operation is like that of a steam engine, except there is no combustion involved. Liquid nitrogen is pressurized and then vaporized in a heat exchanger by the ambient temperature of the surrounding air. The resulting high - pressure nitrogen gas is fed to the engine converting pressure into mechanical power. The only exhaust is nitrogen.
The usage of cryogenic fuels has significant advantage over other fuel. Also, factors such as production and storage of nitrogen and pollutants in the exhaust give advantage for the cryogenic fuels
INTRODUCTION
The importance of cars in the present world is increasing day by day. There are various factors that influence the choice of the car. These include performance, fuel, pollution etc. As the prices for fuels are increasing and the availability is decreasing we have to go for alternative choice.
Here an automotive propulsion concept is presented which utilizes liquid nitrogen as the working fluid for an open Rankine cycle. When the only heat input to the engine is supplied by ambient heat exchangers, an automobile can readily be propelled while satisfying stringent tailpipe emission standards. Nitrogen propulsive systems can provide automotive ranges of nearly 400 kilometers in the zero emission mode, with lower operating costs than those of the electric vehicles currently being considered for mass production. In geographical regions that allow ultra low emission vehicles, the range and performance of the liquid nitrogen automobile can be significantly extended by the addition of a small efficient burner. Some of the advantages of a transportation infrastructure based on liquid nitrogen are that recharging the energy storage system only requires minutes and there are minimal environmental hazards associated with the manufacture and utilization of the cryogenic "fuel". The basic idea of nitrogen propulsion system is to utilize the atmosphere as the heat source. This is in contrast to the typical heat engine where the atmosphere is used as the heat sink.
HISTORY
The LN2000 is an operating proof-of-concept test vehicle, a converted 1984 Grumman-Olson Kubvan mail delivery van. Applying LN2 as a portable thermal storage medium to propel both commuter and fleet vehicles appears to be an attractive means to meeting the ZEV regulations soon to be implemented. Pressurizing the working fluid while it is at cryogenic temperatures, heating it up with ambient air, and expanding it in reciprocating engines is a straightforward approach for powering pollution free vehicles. Ambient heat exchangers that will not suffer extreme icing will have to be developed to enable wide utility of this propulsion system.
Since the expansion engine operates at sub-ambient temperatures, the potential for attaining quasi-isothermal operation appears promising. The engine, a radial five-cylinder 15-hp air motor, drives the front wheels through a five-speed manual Volkswagen transmission. The liquid nitrogen is stored in a thermos-like stainless steel tank. At present the tank is pressurized with gaseous nitrogen to develop system pressure but a cryogenic liquid pump will be used for this purpose in the future. A preheater, called an economizer, uses leftover heat in the engine's exhaust to preheat the liquid nitrogen before it enters the heat exchanger. The specific energy densities of LN2 are 54 and 87 W-h/kg-LN2 for the adiabatic and isothermal expansion processes, respectively, and the corresponding amounts of cryogen to provide a 300 km driving range would be 450 kg and 280 kg. Many details of the application of LN2 thermal storage to ground transportation remain to be investigated; however, to date no fundamental technological hurdles have yet been discovered that might stand in the way of fully realizing the potential offered by this revolutionary propulsion concept
Cryogens are effective thermal storage media which, when used for automotive purposes, offer significant advantages over current and proposed electrochemical battery technologies, both in performance and economy. An automotive propulsion concept is presented which utilizes liquid nitrogen as the working fluid for an open Rankine cycle. The principle of operation is like that of a steam engine, except there is no combustion involved. Liquid nitrogen is pressurized and then vaporized in a heat exchanger by the ambient temperature of the surrounding air. The resulting high - pressure nitrogen gas is fed to the engine converting pressure into mechanical power. The only exhaust is nitrogen.
The usage of cryogenic fuels has significant advantage over other fuel. Also, factors such as production and storage of nitrogen and pollutants in the exhaust give advantage for the cryogenic fuels
INTRODUCTION
The importance of cars in the present world is increasing day by day. There are various factors that influence the choice of the car. These include performance, fuel, pollution etc. As the prices for fuels are increasing and the availability is decreasing we have to go for alternative choice.
Here an automotive propulsion concept is presented which utilizes liquid nitrogen as the working fluid for an open Rankine cycle. When the only heat input to the engine is supplied by ambient heat exchangers, an automobile can readily be propelled while satisfying stringent tailpipe emission standards. Nitrogen propulsive systems can provide automotive ranges of nearly 400 kilometers in the zero emission mode, with lower operating costs than those of the electric vehicles currently being considered for mass production. In geographical regions that allow ultra low emission vehicles, the range and performance of the liquid nitrogen automobile can be significantly extended by the addition of a small efficient burner. Some of the advantages of a transportation infrastructure based on liquid nitrogen are that recharging the energy storage system only requires minutes and there are minimal environmental hazards associated with the manufacture and utilization of the cryogenic "fuel". The basic idea of nitrogen propulsion system is to utilize the atmosphere as the heat source. This is in contrast to the typical heat engine where the atmosphere is used as the heat sink.
HISTORY
The LN2000 is an operating proof-of-concept test vehicle, a converted 1984 Grumman-Olson Kubvan mail delivery van. Applying LN2 as a portable thermal storage medium to propel both commuter and fleet vehicles appears to be an attractive means to meeting the ZEV regulations soon to be implemented. Pressurizing the working fluid while it is at cryogenic temperatures, heating it up with ambient air, and expanding it in reciprocating engines is a straightforward approach for powering pollution free vehicles. Ambient heat exchangers that will not suffer extreme icing will have to be developed to enable wide utility of this propulsion system.
Since the expansion engine operates at sub-ambient temperatures, the potential for attaining quasi-isothermal operation appears promising. The engine, a radial five-cylinder 15-hp air motor, drives the front wheels through a five-speed manual Volkswagen transmission. The liquid nitrogen is stored in a thermos-like stainless steel tank. At present the tank is pressurized with gaseous nitrogen to develop system pressure but a cryogenic liquid pump will be used for this purpose in the future. A preheater, called an economizer, uses leftover heat in the engine's exhaust to preheat the liquid nitrogen before it enters the heat exchanger. The specific energy densities of LN2 are 54 and 87 W-h/kg-LN2 for the adiabatic and isothermal expansion processes, respectively, and the corresponding amounts of cryogen to provide a 300 km driving range would be 450 kg and 280 kg. Many details of the application of LN2 thermal storage to ground transportation remain to be investigated; however, to date no fundamental technological hurdles have yet been discovered that might stand in the way of fully realizing the potential offered by this revolutionary propulsion concept
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