Israeli Develops 'Disruptive' Jet Engine

New R-Jet gas turbine engine intends to improve fuel efficiency and cut harmful greenhouse gas emissions by more than 20 percent.

Published: 27-Mar-2007

When asked what makes his new jet engine unique, leading Israeli engineer, Prof. David Lior will tell you what he says General Electric told him: that his invention is "disruptive technology."
Lior's company, R-Jet Engineering, is currently developing a new gas turbine engine that intends to improve fuel efficiency and cut harmful greenhouse gas emissions by more than 20 percent. The new engine has fewer components, smaller dimensions and is lighter weight than conventional engines. It also significantly cuts operation and maintenance costs.
In a field that hasn't seen significant technological innovation like this in more than 50 years, Lior says his engine is a huge step in the right direction.
It is an innovation, he says, that will "disrupt" the decades-long stalemate in development facing the aviation industry, providing engine suppliers and manufacturers with a more fuel-efficient, environmentally friendly and cost-effective engine.
The OCN (Orbiting Combustion Nozzle) engine is currently in the development stages at the small company's base in Herzilya, Israel, and is set for release in the next two to three years. The engine's primary application will be for low-cost, efficient electrical power generation, which can be placed anywhere – hospitals, schools and commercial centers, Lior says.
The cost of power generation is expected to be reduced by about 20% compared to other methods, with overall efficiency in OCN distributed power generation reaching more than 85%, double that of conventional methods.
The technology can also be used for other propulsion applications and in commercial aircraft and helicopters that use turbo-fan, turbo-jet, and turbo-shaft engines.
"The distributed power generation is considered ‘green’ technology, and the OCN engine, when in the market in about three years, has the potential of becoming a substantial player in this emerging market," explains, R-Jet co-founder, Giora Belkin.
Potential clients or collaborators include engine manufacturers such as General Electric, Pratt and Whitney, Rolls Royce, Turbo Mecca and Microturbo. R-Jet will either work through joint ventures or license potential clients to produce the new technology, an invention that Lior estimates will take 2%, or more than $200 million a year, of the current market.
The project receives 40% of its funding from the Israel Ministry of Industry, Trade and Labor through the R&D grant program at the Office of the Chief Scientist. Rafael Armament Development Authority owns 10% of the company.
According to the chief of staff at the Office of the Chief Scientist, Elad Stav, if commercially successful, R-Jet Engineering will be obligated to pay 3-5% in royalties to the ministry, up to the amount of the awarded grant. Stav says that the committee in charge of approving grant applications looks for Israeli R&D projects that are highly innovative.
In conventional gas turbine engines, the combustion that powers the engine is conducted in a static setting at a low velocity in the engine's core chamber. In the OCN engine, however, the combustion occurs in a high velocity medium called a vortex, where the air is constantly moving and flowing. Fuel is burned in the vortex of air created by the OCN engine. This saves energy otherwise lost in conventional engines, in which air decelerates when diffused into the combustion chamber, and accelerates again when it flows into the turbine.
"We avoid this deceleration and acceleration by keeping the air rotating all the time. This is why we gain a lot of fuel savings," says Lior.
By creating more effective combustion, the OCN engine uses 25-30% less fuel than its counterparts, fuel being one of the most significant costs for the airline industry. The engine also releases 20% fewer toxic pollutants into the environment, such as carbon hydrates (CH), carbon dioxide (CO2) and nitrogen oxides (NOx), which may contribute to climate change and global warming.
"Every single liter of fuel that you save means that you are not actually putting CO2 and other noxious substances into the atmosphere like NOx and carbon monoxide, that we know create greenhouse gas warming issues," says aviation consultant and editor of Janes Airport Review, Philip Butterworth-Hayes.
"Aviation is already a major source of CO2 and other greenhouse gas emissions. It is also rising very fast, faster than any other transport sector," says communications officer, Dudley Curtis, for the European Federation for Transport and Environment (T&E), an environmental organization that promotes sustainable and environmentally sound transport, focusing primarily on European policy.
Reducing fuel use does not only cut airline expenses, says Curtis, but it is also directly linked to the reduction of the harmful emissions produced by fuel burning. The organization claims the aviation sector is responsible for 4-9% of the global, human-produced impact on climate change, the greatest climate impact of any transportation mode.
"We know pollution of aircraft is particularly bad because it is in the upper atmosphere and therefore its contribution to global warming is particularly significant," explains Israeli director of Friends of the Earth Middle East, Gidon Bromberg.
In 1999, the Intergovernmental Panel on Climate Change (IPCC) estimated that aviation was responsible for 3.5% of the human contribution to climate change, including C02and non-CO2 effects. This estimate does not include the effects on cirrus clouds, however, which other environmental advocates say significantly increases the impact.
While statistics vary, according to the IPCC and environmental organizations, total aviation emissions are increasing every year, as demand for air transport outpaces reductions in emissions from technological and operational advancements.
[The environment] is really the major issue right now. Every year, there are new engine requirements, specifically in California but mostly in Europe, says Lior. "Everybody is trying to cut down CO2 pollution, CH pollution, NOx pollution – and we make it better through more efficient combustion."
The European Commission has considered integrating air transport into the EU emissions trading system, turning more focus on the effects of aviation emissions on the environment.
"In Europe, a new engine design would need to be at least 10% more fuel-efficient, with lower emissions from burning fuel," says Butterworth-Hayes.
Hayes explains that new engines designed for the aviation industry need to both minimize CO2 and NOx emissions, and at the same time create efficient combustion that can get the engines operating at their peak, maximizing the power of the engine while minimizing its "environmental footprint."
In addition to being more fuel-efficient and environmentally friendly, Lior says the OCN design is also more compact and cost-effective, assets that will likely appeal to manufacturers and airlines.
The OCN engine isabout half the weight and size of other conventional gas turbine engines. Its design eliminates expensive components such as the diffuser and turbine stator, and it has fewer turbine stages, therefore cutting production costs nearly in half. 
The engine's turbines are more powerful and more efficient, says Lior, working at supersonic rather than transonic speeds. This creates more energy per turbine stage, requiring less turbine stages in total. 
It also has a unique blade-cooling method, which allows it to attain high efficiency even in small engines, which R-Jet says is not possible in small conventional gas turbines.
The last significant development in terms of fuel-efficiency of jet engines, says Butterworth-Hayes, was the introduction of high bypass ratio engine in the late 1970s and early 1980s.
"We are not able to make those quantum leaps in engine efficiency any more. We are about as efficient as we can get from extracting as much energy as we can from the fuel," he says. “We can tweak it, but we can't get those 30, 40, 50% increases in efficiency that we did when we introduced the last major design change."
In their 2006 report, "Clearing the Air: The Myth and Reality of Aviation and Climate Change," E&T claims that: "Today's passenger aircraft are no more fuel-efficient than those that flew half a century ago."
Curtis says the aviation community often refers to a claim of a 70% improvement in fuel efficiency over the past 40 years, but says these figures can be misleading.
Lior says that the engines currently being used in aircraft follow practically the same concept as they did 70 years ago, when Frank Whittle invented the turbine-powered jet engine to replace the piston engine.
That is why the OCN design is a step into unexplored territory, he says.
"[What airlines are looking for] all depends where you are in the world. If you are in Europe, it is increasingly important to keep the CO2 emission count down. If you are in the States, then you are looking for quiet engines. There the issue is noise rather than CO2 emissions. If you are in Africa, you don’t really care as long as it's safe, efficient, and cheap," explains Butterworth-Hayes.
"There is not one single technology or policy that can solve the problem," says E&T director, Jos Dings. Dings explains that aviation in Europe, unlike other transportation sectors, is generally unregulated when it comes to the environment.
"The aviation industry is a heavily subsidized market that doesn’t pay taxes on fuel," says Dings.
The sector is not covered by the Kyoto Protocol on climate change, and the Netherlands is the only European country that taxes fuel, according to E&T. The organization is currently working to incorporate the aviation industry into the EU Greenhouse Gas Emissions trading scheme, hoping to reduce the sector's environmental impact through policy.
"If we are talking about climate change, the key issue at moment, what we care about is reducing emissions," says Curtis. "Now, however you get there, if by its technology or whatever you do, then that’s fine. But if it’s a tiny bit of reduction in emissions to pave the way for continued enormous growth from aviation, then that is clearly not acceptable.
What we would rather see from the industry is a commitment to cut emissions or stabilize emissions at a certain level rather than saying: 'Ah, well, we are investing $x-billion in technology and all the rest of it, because these figures make nice headlines, but they don’t actually reduce emissions."

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