Machined cavities in pistons improve fuel economy

James Bauernschmidt writes:
Here are links to my articles about Sonex: their content (minus the pictures) are inserted below http://www.washingtonfreepress.org/73/gasEngineUse Diesel.htm http://www.gizmag.com/go/4695/

for a picture of the piston, see http://www.gizmag.com/pictures/hero/4695_310058131 2.jpg

Can a gas engine use diesel fuel with less pollution?

by James Bauernschmidt

Anyone concerned with rising oil prices and pollution from fossil fuel might like to know about a new technology, which addresses both problems. Its application will put an end to the days of sooty smoke seen from accelerating diesel trucks and buses. The technology involves a slight modification to an engine part that can be mass-produced on existing manufacturing lines.

The technology is the result of over thirty years R&D conducted by Dr. Andrew Pouring, a former professor and chairman of the Dept. of Aerospace Engineering at the US Naval Academy. Through his company Sonex Research, Inc. in Annapolis, MD (see www.sonexresearch.com), his work focused on improving the process of combustion through a combination of chemical and fluid dynamic effects. The technology is manifested in the new design of piston heads inside the engine. The Sonex pistons have uniquely shaped chambers with holes in them which bring about a more complete combustion through the turbulence created by high speed air flows emitted from the chambers. (See diagram below).

The new piston can be used in one of two ways in a direct-injected (DI) engine.

A standard DI diesel engine at compression ratios greater than 16:1 can be equipped with the Sonex piston, enabling overall soot reduction of approximately 50% and a reduction in NOx of 10% without exhaust gas recirculation. This application has little affect on fuel economy. These results were positively evaluated by the world-famous laboratory, Ricardo Consulting Engineers in England.

(Continued) But the most advantages come when applying the Sonex piston in a DI gasoline engine with compression at 12.5:1 or lower, while using a variety of fuels. This design is called Sonex Controlled Auto Ignition (SCAI). The SCAI process is basically controlled HCCI (Homogeneous Charge Compression Ignition), which manufacturers world wide are seeking to control because of its low emissions and good fuel economy. The beauty of the SCAI process is that it enables a gas engine to run with no spark plugs using either a heavier fuel such as diesel or military fuel JP5 or lighter alcohol fuels with greater efficiency and cleaner exhaust. Using JP5 in a single cylinder engine, the Sonex laboratory measured an overall soot reduction of approximately 90% and NOx reduction of approximately 80%. The need for elaborate aftertreatment of the exhaust is minimized. The result is a much lighter and more fuel-efficient engine which can run on heavier or lighter fuels, including gasoline. Sonex has recently successfully applied their SCAI process to a six-cylinder Subaru gas engine using JP5 fuel under a DARPA (Defense Advanced Research Projects Agency) contract and is confirming its single cylinder results.

Diesel fuel offers several advantages over gasoline. Diesel is easier to make at our overworked refineries. MTBE contamination from gas tanks is not an issue. Diesel fuel is also not explosive (it will extinguish a burning match), so transporting it to gas stations would not attract terrorist activity. For several years, the US military has been trying to switch to using only a uniform kerosene based fuel (JP5) similar to diesel. Problems of attacks on convoys transporting gasoline have already confronted our forces in Iraq and reaffirmed the need for improvement. Also, because diesel is a heavier fuel, it contains more energy. The US Marine Corps has already applied another version of Sonex technology in their UAVs (unmanned aviation vehicles) with success. The same UAVs are now able to fly 20% farther using heavy fuel thanks to the Sonex technology.

Unlike the hydrogen economy which will require vast changes to our infrastructure taking several decades, a diesel economy can be established now by using Sonex. However, several auto manufacturers either offer no diesel vehicles or diesels which are unavailable in several states because of emissions problems. They no longer have an excuse. With Sonex, much higher EPA standards are achievable. Ultimately, you, the customer, should determine what products are offered. Please tell your elected officials to mandate higher standards for industry.

The above article was edited by the Sonex inventor, Dr. Andrew Pouring. The writer, James Bauernschmidt, is a minor shareholder of Sonex (1% of outstanding shares). He can be reached at bauernschmidt@usa.net. The patent number for the Sonex piston is US 5,862,788, issued January 26, 1999.

New technology turns petrol engines into low compression diesel! (link to this article) October 3, 2005 It has been a sudden realisation - the world is running out of oil and the laws of supply and demand are set to make petrol prohibitively expensive in the very near future. Sonex Research has a new combustion technology that offers significantly better fuel consumption and greatly reduced emissions. The Sonex GDI Combustion System uses pistons modified to carry a chemical charge that initiates combustion from one cycle to the next, thus eliminating the need for spark plugs. High compression, typical of diesel engines, is no longer needed to make the fuel ignite; in fact, the chemistry causing this auto ignition process exists only at lower compression ratios. Thus, a low compression engine, typically used for burning gasoline, can be designed to burn either a lighter alcohol fuel like ethanol, or a heavier fuel like (bio)diesel when equipped with Sonex pistons, common rail direct injection system and associated electronic control system to control injection pressure and timing. The technology could well be first deployed powering UAVs for the military in Iraq. By James Bauernschmidt

Sonex Research Company of Maryland, USA, believes much better fuel efficiency will be achievable when the Sonex Controlled Auto Ignition (SCAI) system is fully developed for Gasoline Direct Injected (GDI) engines using no spark ignition or throttle. The Sonex GDI Combustion System could improve fuel mileage by at least 25%. Dr. Andrew Pouring, a former chairman of the Dept. of Aerospace Engineering at the US Naval Academy, in his research found that pistons can be modified to carry a chemical charge that initiates combustion from one cycle to the next, thus eliminating the need for spark plugs. High compression, typical of diesel engines, is no longer needed to make the fuel ignite; in fact, the chemistry causing this auto ignition process exists only at lower compression ratios.

Thus, a low compression engine, typically used for burning gasoline, can be designed to burn either a lighter alcohol fuel like ethanol, or a heavier fuel like (bio)diesel when equipped with Sonex pistons, common rail direct injection system and associated electronic control system to control injection pressure and timing.

The piston head is designed with micro-chambers (MC) containing small connecting holes to the main combustion bowl in the piston. The initial combustion is brought about by the use of glow plugs which are turned off after starting. When fuel is directly injected into the engine at a precise moment, the SCAI design allows a small portion of the fuel to enter the MC.

This allows a slow chemical reaction in the MC which continues into the next compression cycle, thus providing the "chemical spark" for the next combustion. In a low compression engine, a more complete combustion of the fuel occurs at a lower temperature. As a result, soot and toxic emissions get reduced by over 80%. The turbulence of high-speed airflows in the connecting passages and the MC chemical reactions prevent these chambers from ever becoming clogged. A heavier fuel with more energy in it can now run in a lightweight engine more efficiently and with cleaner exhaust. Consequently, Sonex brings about the best of both worlds.

The main customer of SCAI has been DARPA (Defense Advanced Research Projects Agency). Currently, under their DARPA contract, Sonex Research is continuing development of a multi-cylinder, high power output, lightweight piston engine to comply with a DoD policy directive that mandates heavy fuel for all engines; this engine has already demonstrated a 25% reduction in fuel consumption compared to its performance on gasoline.

Gasoline engines are typically 25% to 30% lighter than diesel engines. Gasoline engine designs with the SCAI technology that can burn kerosene-based heavy fuels (JP5/8) would address DoD performance, logistics, and safety requirements.

So why hasn't the automotive industry snatched up this technology? It's the "not invented here mentality" according to Dr. Pouring. "If the automaker hasn't invented the technology in its own house, the automaker is highly reluctant to use it, moreover, the automaker requires full compliance with emissions regulations before even taking a look. This is a daunting task."

However, circumstances might make this industry reconsider. Fuel efficiency improvement is addressed in the Energy Bill signed into law in August in the USA. Section 773 states: "..the National Highway Traffic Safety Administration (NHTSA) shall initiate a one-year study and report to Congress of the feasibility and effects of reducing by model year 2014, by a significant percentage, the amount of fuel consumed by automobiles."

Sonex Research seeks to be at the forefront of this initiative by providing this NHTSA study with compelling data on how its technology could cost-effectively improve fuel mileage 25% to 30% while reducing exhaust emissions. Once the US Congress is made aware that much higher standards are achievable, these standards could become mandated as federal law. In the meantime, consumers can rightfully demand better engines, knowing the Sonex technology is available.