Wouldn’t it be nice, if we would use half the amount of gasoline for a Dallas Unit (distance between Austin-Dallas = 200 miles) than we are currently using (around 6.5 gallons for a 30 mpg Chevvy Malibu) and simultaneously keep our environment clean. When buying a car or motorcycle, we all want to know the mpg (miles per gallon) ratings for that vehicle and wish that it could do more with the same amount of fuel, because lower is the mpg for that vehicle, more are the monthly driving costs.
U.S. petroleum imports are predicted to increase about 35 percent by 2030. At the same time, the transportation-related emission of carbon dioxide is expected to rise by about 35 percent in the United States.
What could be changed in a car or motorcycle which reduce fuel consumption and reduce harmful emissions? The main element of a vehicle which propels it is the combustion engine also known as Internal Combustion engine (because the combustion takes place inside the cylinder). Typically an IC engine utilizes less than 30% of the fuel’s potential energy, while over 70% of its energy is lost. There is some degree of variability in this efficiency depending on how old the engine is and whether it has some of the modern fuel delivery mechanisms (multi-point injection) or some sort of digital control.
But the basic design of IC engine has remained the same over the last century. Here I will point three radical designs for IC engines which are remarkably different than the basic design and boast of improving the fuel efficiency to the point where we would be able to save more and pollute less.
1) Six-stroke engine – Developed by 75-year-old mechanic Bruce Crower, a veteran of the racing industry and a the owner of a company which produces high-performance cams and other engine parts, this new design boasts to improve fuel economy by changing the way typical IC engine works. A typical IC engine is a 4-stroke engine, where the cycle consists of air+fuel intake, compression, ignition and expulsion of gases from cylinder. We all know that the exhaust from a car is very hot, and we need a radiator (which also consumes energy) to keep the engine cool. So what this design does it that after the 4th stroke of IC engine, it introduces distill water in the cyliner which turns into steam and expands 1600 times to give one more push to the vehicle. In effect, it utilizes the waste energy and keeps the engine cool and markedly increases the fuel efficiency.
2) Tour Engine – Developed by Hugo Tour, who after 30 years servicing Israel’s military aircraft, asked himself – if jet engines and water heaters can achieve high rates of efficiency, then why not a car’s internal combustion engine?’ and came out with this design known as Tour Engine (which is a split cycle engine). What the split cycle engine does is that it splits the engine into two; in one part the intake of fuel+air and the compression takes place (which are the cold strokes) and in the other combustion and exhaust takes place (which are the hot strokes). And by doing so it gets rid of the inherent inefficiency of a typical 4-stroke engine because of all the 4 strokes in the same cylinder. When tested in US laboratories, the Tour Engine can achieve efficiency levels of about 65% but the real life efficiency will probably be less, but Hugo Tour believes it will be twice as efficient as today’s internal combustion engine.
3) Homogeneous Charge Compression Ignition Engines (HCCI) with Variable Valve Actuation – the name may sound alien but the concept here is a good one. Dr. George M Shaver’s resaerch group at Purdue university is trying to bring this concept to realisation. What they are working on is, to mix a portion of car exhaust with the fuel+air mixture going into the engine and thus increasing engine efficinecy by higher fuel efficiency and reducing engine temperature. By reducing the engine temperature, they would literally eliminate all of the nitrous oxides produced and also reduce the CO2 and particulate matter emissions by higher fuel economy. The expected increase of fuel economy is 15-20%. Dr. Shaver was the lead author of a research paper honored with the 2006 Rudolf Kalman Paper Award for the best paper published in the Journal of Dynamic Systems, Measurement, and Control.
What all of these innovations will do? Reduce US oil consumption and as well as help to reduce emissions of GHG gases. But before we own a car which runs on an IC engines in these designs, it will take some more commitment of funding, people power, industrial involvement and academic involvement.