Rapid Prototyping Technologies And It’s Applications

The technology used in rapid prototyping printers for producing 3D models is computer assisted design (CAD) software such as Pro-e, Auto CAD, Solid-works, and etc,  which directs hardware to precise specifications to produce three dimensional models. The efficiency of rapid prototyping to produce models for various companies and allow design changes to be made quickly and easily has found this technology an excellent solution for fulfilling their rapid prototyping needs. As the implications for rapid prototyping printers continue to develop the applications for the manufacturing of products is expanding. If a product is desired by the business they can simply purchase a CAD file upload it and use rapid prototyping printers to reproduce it. With fabrication materials for use in rapid prototyping printers continuing to advance the use of metals, plastics and polymers contributes to the wide application of rapid prototyping printers.

Convenience of Using Rapid Prototyping Printers

Rapid prototyping printers not only make product availability more convenient for companies but for consumers also. The technology once used only by manufacturers is now available for consumer use in their business or at home. Rapid prototyping printers provide an enhanced ability for the production of models and products. If a new brush or comb is desired, rapid prototyping printers can produce one very conveniently. Rapid prototyping printers can be used for a variety of products constructed of numerous kinds of materials. The technology used in rapid prototyping printers is computer assisted design software utilized to build a 3 dimensional model. The model is produced layer by layer until an exact reproduction is produced according to the specifications dictated by the program.

If a small business needs a product or model produced there is no need to maintain workshops with specialized tools or expensive skilled craftspeople as with traditional modeling. Rapid prototyping printers can provide the technology necessary to produce 3D models more conveniently and in shorter periods of time and for less money. In today’s business environment in order for a small business to grow the capability to produce products in a cost efficient manner is crucial for success. Rapid prototyping printers provide the technology for small businesses that are seeking more convenient and cost effective manufacturing options.

Growing Applications for Rapid Prototyping Printers

The computer assisted design applications of rapid prototyping printers are numerous compared to traditional prototyping methods. Traditional methods required the use of large, bulky and sophisticated equipment which also required a major investment for businesses to own. Rapid prototyping printers however are reasonably sized, compact and much less expensive. The set up time and simple operation has made rapid prototyping printers popular for creating models, machine parts and toys.

The almost unlimited flexibility and potential applications of rapid prototyping printers to create replicas is a distinct applications advantage of this technology over traditional methods. If a CAD program can be created and suitable materials developed the application of rapid prototyping printers is immense.

Also, unlike some prototyping techniques the rapid prototyping printers produces no toxic chemicals from nor uses any toxic substances during the production process. Due to their safe operation the potential locations for where rapid prototyping printers can be set up and operated increases their application potential. Additional advantages gained from the application of rapid prototyping printers is that post production work is minimized, only the removal of excess materials produced during the production process is necessary. The applications of rapid prototyping printers are many including reduced costs, efficiency and safety. As new innovations for rapid prototyping printers are developed so will additional applications and markets open up as well.

World’s First Air-Powered Car | Zero Emissions

India’s largest automaker is set to start producing the world’s first commercial air-powered vehicle. The Air Car, developed by ex-Formula One engineer Guy Nègre for Luxembourg-based MDI, uses compressed air, as opposed to the gas-and-oxygen explosions of internal-combustion models, to push its engine’s pistons. Some 6000 zero-emissions Air Cars are scheduled to hit Indian streets in August of 2008.

Barring any last-minute design changes on the way to production, the Air Car should be surprisingly practical. The $12,700 City CAT, one of a handful of planned Air Car models, can hit 68 mph and has a range of 125 miles. It will take only a few minutes for the City CAT to refuel at gas stations equipped with custom air compressor units; MDI says it should cost around $2 to fill the car’s carbon-fiber tanks with 340 liters of air at 4350 psi. Drivers also will be able to plug into the electrical grid and use the car’s built-in compressor to refill the tanks in about 4 hours.

Of course, the Air Car will likely never hit American shores, especially considering its all-glue construction. But that doesn’t mean the major automakers can write it off as a bizarre Indian experiment — MDI has signed deals to bring its design to 12 more countries, including Germany, Israel and South Africa.

Dual Fuel System

This hydrogen engine takes advantage of the characteristics of Mazda’s unique rotary engine and maintains a natural driving feeling unique to internal combustion engines. It also achieves excellent environmental performance with zero CO2 emissions.

Further, the hydrogen engine ensures performance and reliability equal to that of a gasoline engine. Since the gasoline version requires only a few design changes to allow it to operate on hydrogen, hydrogen-fueled rotary engine vehicles can be realized at low cost. In addition, because the dual-fuel system allows the engine to run on both hydrogen and gasoline, it is highly convenient for long-distance journeys and trips to areas with no hydrogen fuel supply.

Technology of the RENESIS Hydrogen Rotary Engine:

The RENESIS hydrogen rotary engine employs direct injection, with electronically-controlled hydrogen gas injectors. This system draws in air from a side port and injects hydrogen directly into the intake chamber with an electronically-controlled hydrogen gas injector installed on the top of the rotor housing. The technology illustrated below takes full advantage of the benefits of the rotary engine in achieving hydrogen combustion.

 

 

RE Features suited to Hydrogen Combustion

In the practical application of hydrogen internal combustion engines, avoidance of so-called backfiring (premature ignition) is a major issue. Backfiring is ignition caused by the fuel coming in contact with hot engine parts during the intake process. In reciprocal engines, the intake, compression, combustion and exhaust processes take place in the same location—within the cylinders. As a result, the ignition plugs and exhaust valves reach a high temperature due to the heat of combustion and the intake process becomes prone to backfiring.
In contrast, the RE structure has no intake and exhaust valves, and the low-temperature intake chamber and high-temperature combustion chamber are separated. This allows good combustion and helps avoid backfiring.
Further, the RE encourages thorough mixing of hydrogen and air since the flow of the air-fuel mixture is stronger and the duration of the intake process is longer than in reciprocal engines.

Combined use of Direct Injection and Premixing

Aiming to achieve a high output in hydrogen fuel mode, a direct injection system is applied by installing an electronically-controlled hydrogen gas injector on the top of the rotor housing. Structurally, the RE has considerable freedom of injector layout, so it is well suited to direct injection.
Further, a gas injector for premixing is installed on the intake pipe enabling the combined use of direct injection and premixing, depending on driving conditions. This produces optimal hydrogen combustion.
When in the gasoline fuel mode, fuel is supplied from the same gasoline injector as in the standard gasoline engine.

 

Adoption of Lean Burn and EGR

Lean burn and exhaust gas recirculation (EGR) are adopted to reduce nitrogen oxide (NOx) emissions. NOx is primarily reduced by lean burn at low engine speeds, and by EGR and a three-way catalyst at high engine speeds. The three-way catalyst is the same as the system used with the standard gasoline engine.
Optimal and appropriate use of lean burn and EGR satisfies both goals of high output and low emissions. The volume of NOx emissions is about 90 percent reduced from the 2005 reference level.

Dual Fuel System

When the system runs out of hydrogen fuel, it automatically switches to gasoline fuel. For increased convenience, the driver can also manually shift the fuel from hydrogen to gasoline at the touch of a button.

Reliability

It is defined as the probability that a given system will perform it’s function adequately for it’s specified period of lifetime under specified operating conditions.

Common measures are :

1. Failure rate.

2. Mean time between failures(MTBF)

3. Survival percentage.

Failure Rate:

Rate which components of population fail.

R(t)=N_s(t)/N_f(t)

Where,

N_s(t)- No. of components that survived during time ’t’

N_f(t) – No. of failures that occurred during the same time.

Mean time between Failures(MTBF):

The reciprocal of the failure rate(1/λ).

Where

λ —-Failure rate.

Failure rate = (No.of failure )/(Time period during all components were exposed to failure)

 

Reliability Analysis:

Failure Mode and Effect Analysis(FMEA)

Purpose :

1. To recommend design changes.

2. To identify design weakness.

3. To help in choosing alternatives.

Four Stages:

I^st Stage – System boundaries and the scope of the analysis is decided.

II^nd Stage – Data Collection

Ex: Specification,Operating Procedure,Working Conditions.

III^rd Stage– Preparing the component or parts list.

IV^th Stage – Failure frequency and the functions of the part identified,causes of       failures,Failure detection.