Engineering a Miracle
Necessity, not magic, is what enables scientists and engineers to create miracles of technology.
Successful research scientists frequently express amazement at the inexplicable, last minute "miracle" that enabled them to reach a seemingly unattainable project goal at the eleventh hour -- and engine research is no exception.
But these miraculous inspirations may have less to do with supernatural forces than with the well-established, scientific adage about necessity being the mother of invention. In that sense, necessity itself, by stimulating effort, is the real miracle worker.
During the 1950s, the Soviet Union challenged U.S. success in space exploration. The United States responded with the Apollo manned space program, announced in May 1961 by President John F. Kennedy with the vow to send a mission to the moon by the end of that decade. Success was achieved in the last half of the last year of that decade -- July 1969 -- when Apollo 11 astronaut Neil Armstrong became the first human being to walk on the moon.
Is there a limit to what engineers can achieve if challenged seriously enough? We are continually surprised by the improvements that can be made with existing systems through innovation.
In automotive and engine technology, the Clean Air Act of 1970 presented the first serious challenge. At that time, unregulated emissions from heavy-duty truck engines in the United States were determined to be, by pioneering work at Southwest Research Institute, about 15 grams per horsepower-hour (g/HP.h) of oxides of nitrogen. The progression of emissions legislation since then is shown in the accompanying figure. Since 1998, trucks have been regulated to 4 g/HP.h of NOx. The latest proposed NOx level from the U.S. Environmental Protection Agency (EPA), announced in May 2000 for heavy-duty trucks in 2007, is 0.2 g/HP.h.
The NOx emissions for heavy-duty trucks will therefore reduce 75 times over the period from 1970 to 2007. Over the same period particulate emissions will reduce 100 times from 1 g/HP.h to 0.01 g/HP.h.
As reported in previous issues of Technology Today®, the Engine and Vehicle Research Division has formed a cooperative research initiative with 22 engine and component companies from the United States, Europe and the Far East to develop innovative, precompetitive technologies to achieve these aggressive limits for 2007. This is known as the Clean Diesel III program.
The EPA determines permissible levels of vehicle emissions, not from what is currently technically possible, but by what the EPA's air quality models determine to be the maximum levels of NOx and hydrocarbon emissions per day permissible to keep ozone levels within acceptable limits.
On many occasions, limits were set with no technology yet available to meet them. These new mandates are frequently accompanied by protests from manufacturers who warn that they could be forced out of business by such deadlines and limits. Obviously, if one manufacturer meets the emissions targets and another does not, the former gains a tremendous competitive advantage. Therefore, an intensive search ensues among manufacturers to develop new or improved technologies to meet these new emissions limits.
The Environmental Protection Agency has, by mandating emissions goals for which there are no known technologies, forced innovation. Because goals in the United States are more severe than in other countries, the industry has responded, and this is one reason why the United States leads the world in heavy-duty truck diesel technology. This heartening success story also illustrates how important it is for engineers in particular, and technologists in general, to be broadly educated in many technologies and even unrelated disciplines, so that they are better able to make the leaps of imaginative problem-solving that highlight the history of great inventions.
Such global thinking and broad-visioned ingenuity have never been more important, for today's engineers are being challenged more intensely than ever. In addition to the continual tightening of limits on "traditional pollutant" emissions, the contention that global warming is a threat to our prosperity is becoming accepted as reality.
On April 21, 2000, the White House announced a bold initiative known as the 21st Century Truck Program. Its goals are to increase the fuel economy of the largest transcontinental trucks in the United States by a factor of 2, and of other trucks and buses by a factor of 3, while at the same time meeting the low emissions levels that are being proposed by the EPA.
The primary purpose of this initiative is to reduce transportation costs for the U.S. consumer and reduce CO2 production, as well as to reduce the nation's dependence on foreign oil supplies. However, the same technologies that are developed for commercial vehicles also can be applied to U.S. military vehicles, thus reducing the logistical burden of carrying fuel in the field -- another incentive for the 21st Century Truck Program. Since 1998, Southwest Research Institute has been contracted with the National Automotive Center, Warren, Mich., which is part of the U.S. Army, to develop technologies that can achieve these aggressive goals.
The task of reducing fuel consumption by two or three times is a daunting one, especially since the diesel engines that power today's trucks already are fairly efficient. However, history suggests that we will meet this challenge. The more serious the threat or pressing the need, the more galvanized and successful scientists are in finding the needed solutions. Just as Sputnik led to Apollo, the threat posed by global warming will no doubt lead to some "miraculous" unforeseen breakthrough in truck fuel economy.
Published in the Spring 2001 issue of Technology Today, published by Southwest Research Institute. For more information, contact Maria Martinez.
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Spring 2001 Technology Today
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