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Car Emission Scandal: Why Is It So Hard to Make Clean Diesel Cars?


Well known overseas carmakers VW, Audi, SEAT and Skoda have agreed to pay penalties totaling over $20,000,000,000. We would like to analyze, understand and explain the roots of the latest US emissions scandal.

After being caught attempting to subvert emissions standards, manufacturers often obscure their malfeasances by overstating the complexity of any proposed solutions. In addition their proposed engineering solutions remain rudimentary. Furthermore, these solutions are often limited in their scope, whereas systemic changes are called for. Changes must be driven by neither production nor business interests, but by a holistic engineering approach.

Modern engine design has fundamentally remained the same for over a hundred years. The basic feature of Diesel and gasoline engines is that all the processes—fresh air charge intake, compression, expansion and exhaust removal – take place within the same cylinder. This places essential restrictions on the entire combustion process. Exhaust gases at high pressure and temperature are dumped into the atmosphere "half-cooked," meaning both fuel residue and heat energy remain in the emissions.

Engineers in the 1930s realized this fact and strived to design steam engines that expend generated energy completely. These engines used double or triple steam expansion, so that steam transforms its entire thermal energy into crankshaft rotation after passing several cylinders. Unfortunately this knowledge has been lost or perhaps ignored. Modern automakers have no desire to change Internal Combustion Engine (ICE) design. There is little to no inclination to capture thermal energy more efficiently.

The development of the modern ICE has already reached its theoretical limits. This means significant improvement is impossible while maintaining current design paradigms. While keeping the current ICE, automakers, engineers, and managers attempt to implement incremental improvements with external devices like afterburners, converters, and catalysts. Thus, they avoid any attempts to utilize exhaust gas energy in such a way that, immediately after leaving the cylinder, gas temperature and pressure are close to those of the environment—to truly exhaust the gas. Specific fuel consumption of such an engine would theoretically be dropped by half while engine power remains the same or increases. This is also a good opportunity to abandon hybrid technology, which is expensive and ineffective from a consumer point of view.

The main reason automakers are unwilling to change the ICE design is a disinclination to incur additional manufacturing costs. However, these costs pale in comparison to the penalties manufacturers pay when they claim lower emissions than they can achieve. It's not a big risk, however: manufacturers pay these astronomic penalties and then recoup their losses by passing costs on to consumers—a practice that is simply seen as the cost of doing business. These penalties are rather a point of competition than an incentive for manufacturers to provide us all with air free of harmful exhaust substances.

When an automaker truly intends to resolve emissions problems, the task should be to modify the entire ICE design in such a way as to ensure exhaust gases leave the cylinder at the temperature and pressure of the environment, having completely transferred their energy to a crankshaft.

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It is a well-known fact that each unit of fuel in the combustion process of a conventional ICE produces energy is consumed by 3 major engine systems--mechanical, thermal, and exhaust--at roughly 1/3 of the total energy absorbed, each. We propose an engine that extracts 1/2 of the energy conventionally lost to the exhaust system, or a third of the total energy (1/2 x 1/3 = 1/6), and injects that energy into the mechanical system. Therefore, the mechanical system captures 1/2 of the total available energy {1/3 + 1/6 = 1/2} derived from the combusted fuel. Preliminary calculations based on computer models show that this engine actually delivers 52% of the total energy as mechanical energy

One proposed design implements extra cylinders to recapture useful exhaust, leading to higher efficiency. Gases at exit have close to environment temperature and pressure and contain much fewer harmful substances

Today, the automotive industry is in a state of bifurcation. The first player to realize, via engineering solutions, substantial increases in ICE efficiency will have the opportunity to capitalize on all future ICE production, giving them a decided competitive advantage. Though this task is neither simple nor inexpensive, it is certainly worthwhile for the long-term health of both industry and the environment. The importance of developing a clean engine cannot be overestimated; while profit motives are an important driver in the business world, the health of future generations is at stake.

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