6. From Chapter 2 we reviewed issues related to the use of fossil fuels - mostly

Question

6. From Chapter 2 we reviewed issues related to the use of fossil fuels - mostly emissions and efficiency. These issues impact the design of internal combustion engines for vehicles. Recently Volkswagen and others have been sued and settled lawsuits because their engines were producing excessive emissions. Conduct an internet search and literature review regarding this and other vehicle emissions scandals. In a brief summary (half page) discuss what emissions were excessive and provide details on at least one engine in question (use terms related to thermodynamics - such as engine displacement, 2/4-stroke, Otto/Diesel, compression ratio, etc.) For the selected engine, please conduct a literature review to briefly discuss how their emissions control systems is meant to operate in order to reduce emissions and see if their operation has any impact on efficiency (also about half a page). Please provide references as footnotes. (20 points)

Explanation / Answer

The turbocharged direct injection programs deployed in nearly 500,000 vehicles by Volkswagen cause regular emission as per the US standard in Laboratory while checking, but it caused 40 times more emission of NOx from the vehicle in real world driving and this was called as VOLKSWAGEN EMMISSIONS SCANDAL or DIESELGATE. The backlash against diesel began in 2015 after Volkswagen admitted to programming engine software to dupe regulators about nitrogen oxide emissions. Actually there would be 10 to 15 more scandals similarly which has the emission standard in the Laboratory but is actually does not meet while in real world.

2.         More Europeans are realizing that the “clean diesel” claim was only half true. Diesel engines burn fuel more efficiently than the gasoline engines that prevail in the United States, and produce less planet-warming carbon dioxide. But they also emit more nitrogen oxides, which can cause asthma and other serious lung ailments and are responsible for urban smog.

3.         .In the 1990s, Volkswagen, Mercedes and BMW were the first to combine computer technology, fuel injection and turbo charging to make diesels quieter and cleaner than the smoking, rattling diesels of old. Diesel’s fuel economy also made it easier for BMW, Daimler and Audi to achieve dominance in the luxury car market in Europe, where the cost of fuel is often four times the cost of gasoline in the United States.

OPEL SCANDAL IN MID 2016.

Automakers actual program their emission control system to deactivate to prevent cause from harm So Opel's affected diesel vehicles shut off all emissions controls at ambient temperatures below 20C (68F), or above 30C (86F), or at speeds over 145 km/h (90 mph), or engine speeds more than 2400 RPM, or at elevations higher than 850 meters (roughly 2800 feet). Opel has a plausible-sounding explanation for each of these parameters—but coincidentally, Opel and every other automaker knows that E.U. emissions testing occurs at ambient temperatures between 20C and 30C, at speeds below 145 km/h, with engine speed never exceeding 2400 RPM; they also know that the highest elevation of an E.U. testing facility is at roughly 800 meters.

FIAT CHRYSLER

            This is similar to the Opel Scandal Fiat's 2.0-liter diesel-powered 500X almost entirely shuts off its emissions control devices after 22 minutes of driving. German environmental activist group DUH, which claims to have uncovered Opel's shutoff software, says a diesel 500X it tested put out between 11 and 22 times the legal limit of NOx emissions when tested with a warm engine. Fiat Chrysler, of course, maintains that its vehicles do not carry defeat devices, and that its products are legal under E.U. rules even if real-world emissions output doesn't match lab findings.

PSA and RENAULT

French antifraud authorities raided Renault headquarters after testing inspired by Volkswagen's diesel debacle found many Renault diesel models emitted more than the legally permissible maximum in real-world driving. Officials found no evidence of a "defeat device" after searching engineers' computers, though the automaker recalled nearly 16,000 European-market diesel-powered SUVs and offered a "voluntary" software fix to reduce the NOx emissions of nearly 700,000 diesel-powered vehicles.

2 STROKE AND 4 STROKE EMISSION

Some 93 percent of the users of automobiles are using two wheelers and 3 wheelers which runs on 2 stroke engines. The exhaust emissions of hydro carbon levels in the 2stroke engines are 5,500 parts per million (ppm), compared which 850 ppm from four-stroke engines.

Pollutant

2-stroke

4-stroke

Carbon monoxide

3.0

3.4

Hydrocarbons (hexane)

0.55

0.085

Nitrogen oxides

0.015

0.1

OTTO AND DIESEL CYCLES

Gasoline is lighter (less dense) and less viscose than diesel, Gasoline vaporizes more readily than diesel at room temperature. This makes gasoline a bit more dangerous because it easily creates enough-concentrated vapors that are easy to ignite into fire. diesel is somewhat better in lubricating things than gasoline

COMPRESSION RATIO

            For increasing the efficiency the compression must be increased in Internal combustion engines. For Gasoline engines. It will ignite automatically if the compression ratio becomes Higher. Either you can have a low-efficient, low-compression engine that uses a cheap fuel, or you can have a high-efficient, high-compression engine that uses expensive, high-refined fuel that wont self-ignite even at high compression levels (a 120 octane gasoline?).

You will get some more informations from the References links given below

REFERENCES

1.http://www.epa.illinois.gov/topics/air-quality/mobile-sources/vehicle-emissions-testing/index

2. http://charming.awardspace.com/otto_diesel/otto_diesel.html

3.https://www.researchgate.net/figure/The-gasoline-Otto-engine-cycle_fig3_260878177

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