The most efficient internal combustion engine is the rocket. Rockets use a nozzle that is close to reversible expansion. The combustion chamber is boiling and pressured. But the exhaust is relatively calm. They can be as much as 60-70% efficient. But there are other types of engines that are more efficient than rockets.
High-Efficiency Hybrid Cycle (HEHC)
The high-efficiency hybrid cycle is an advanced 4-stroke thermodynamic cycle that combines elements of the Otto, Diesel, Atkinson, and Rankine cycles. It is designed to improve fuel efficiency while delivering greater power and torque. This new cycle is ideal for use in hybrid electric vehicles.
The real HEHC has higher cycle efficiency with a hydrogen doping fraction of 0.3. It also has a lower indicated fuel cost and lower emissions than pure gasoline. This new technology was developed in 2003 by Nikolay Shkolnik, a former MIT student. In 2004, he learned about the MIT $50K and $100K Entrepreneurship Competitions, and he and his team developed a business plan for the competition. They pitched their HEHC engine at the competition and won the runner-up prize.
LiquidPiston is developing engines based on its patented High-Efficiency Hybrid Cycle. This technology enables fuel-energy conversion solutions for hybrid power systems and auxiliary power units. With its HEHC technology, LiquidPiston is well-positioned to address the challenges posed by DoD and other broader mobility applications.
HEHC is an advanced thermodynamic cycle that borrows elements of the Otto, Atkinson, and Diesel cycles. The essential features of the HEHC engine include a compressor, an isolated combustion chamber, a rotor, and an oscillating rocker. Its design is similar to a diesel engine but offers higher fuel efficiency.
The HEHC engine incorporates a four-stroke cycle that includes intake, compression, expansion, and exhaust. Its design features a ported rotor that allows entire four-stroke operation without poppet valves. Consequently, HEHC engines offer lower noise, vibration, and harshness characteristics.
LiquidPiston, a company specializing in advanced internal combustion engine design, has received a $2.5 million DARPA grant to develop its patented high-efficiency hybrid cycle engine. The company has won two DARPA awards in the last 18 months and has already tested two rotary engine prototypes.
Wartsila 31 engine
Developed by Wartsila engineers, the Wartsila 31 engine is the company’s latest development. Based on a modular architecture, it has doubled the commonality of engine components and took half the time to develop. Its design allows for easy parts replacement. The engine’s modular approach also reduced the development costs by over 10 million Euros.
This engine can run on various fuels, including low-sulfur diesel and Liquefied Natural Gas. Its high power density and long overhaul intervals make it an excellent choice for offshore vessels. Its unique construction makes it possible to use two-stage turbocharging, a feature currently unavailable in a diesel engines.
The Wartsila 31 engine is the world’s most efficient internal combustion engine. It delivers a diesel fuel consumption of 165 grams per kWh, which is lower than any other four-stroke diesel engine. The engine is designed to run in a range of power outputs between 4.2 and 9.8 megawatts. This is enough to power most medium-sized vessels.
Compared to conventional power plants, Wartsila 31 engine is more flexible and responsive to operating conditions. In addition to its superior efficiency, it also offers increased productivity and profitability. Its two-stage turbocharger recovers energy from exhaust gases, resulting in improved fuel efficiency. It can also resist de-rating in humid ambient conditions.
Another advantage of the Wartsila 31 engine is that it emits fewer pollutants than conventional engines. This engine is compliant with EPA and IMO emission regulations. It also can switch between gas and diesel fuel. This means less diesel fuel consumption and fewer emissions.
The Wartsila 31 engine is the world’s most fuel-efficient four-stroke internal combustion engine. It uses less than 165 grams of fuel per kWh when operating at its optimum. It is available for ships of all sizes, from offshore vessels to ferries.
With this technology, Wartsila has revolutionized the marine and energy industries. It has become one of the largest manufacturers of ship engines worldwide and powers one in every third of all commercial vessels. The company is committed to achieving sustainability and maintaining profitable growth while providing environmentally sound products. Its operations span 200 locations in 70 countries and employ over 18,000 people globally.
The Scuderi Group, based in West Springfield, Mass., is working on a new type of internal combustion engine. The company claims the new Scuderi Engine will achieve fuel efficiency of up to 65 miles per gallon (U.S.) and 77 mpg (U.K.) compared to a base model gasoline vehicle. It will also emit significantly less CO2 than a conventional engine. The new engine is expected to double a car’s mileage and increase power output while costing hundreds of dollars less than a traditional hybrid system.
The Scuderi engine has two cylinders. The first cylinder handles the intake and compression strokes, while the other cylinder combusts and exhales the compressed air. This design was perfected by Scuderi, who added an auxiliary compressed air storage tank to the engine. He also modified the point of combustion in the second cylinder. Usually, compressed air ignites before the piston on the up-stroke, while in the Scuderi, ignition occurs at the bottom of the cylinder, where the piston is on the down-stroke.
In a SwRI study, engineers analyzed a sample of European high-economy gasoline city cars and calculated the optimum Scuderi Engine. These specifications were then translated to gear ratios and final drive ratios. The result was a prototype engine with a high-efficiency rating and minimal manufacturing costs. The engine was tested to see if it met the target vehicle’s performance requirements.
The Scuderi Engine can easily be adapted into a production vehicle using conventional parts. The Scuderi Engine is expected to be licensed within three years. The U.S. government is introducing new rules regarding fuel economy that will make adopting alternative engines more attractive.
The Scuderi Engine is a revolutionary design that employs split-cycle technology. It achieves greater thermal efficiency, volumetric efficiency, and overall efficiency. This type of engine also reduces soot and NOx emissions. While Scuderi is still in its infancy, it is believed to be the world’s most efficient internal combustion engine.
The U.S. government and independent laboratories have tested the Scuderi engine. It is compatible with gasoline and diesel automobiles and commercial vehicles. Its unique split-cycle design has the potential to be compatible with alternative fuels.
Honda 1.5L turbo
Honda’s 1.5L turbo four-cylinder engine is one of the market’s most fuel-efficient internal combustion engines. Its cooling system vaporizes fuel and routes it back into the combustion chamber via the crankcase ventilation system. Short drives and cold weather increase fuel evaporation. This can cause the engine oil level to rise and lead to misfires or other symptoms.
The Honda 1.5L turbo engine features an aluminum cylinder block, head, and connecting rods. These components are lightweight and have an optimized skirt design to minimize vibration and maximize operating efficiency. The pistons are also cooled by oil spray jets. In addition, there are four valves per cylinder. The engine uses DOHC (double overhead cam) technology driven by a timing chain.
The engine’s fuel efficiency is one of its main selling points. It has been praised for its fuel economy and performance. Honda incorporated the engine into the CR-V crossover, the best-selling compact crossover in the U.S. It is also used in the larger Accord sedan. The Honda 1.5L turbo engine is also available in many other lightweight vehicles.
The EPA uses ALPHA to determine CO2 emissions. ALPHA uses a physics-based computer simulation model to analyze various vehicle types and powertrain technologies. It can also use a variety of parameters, such as torque and horsepower. The results are shown in Table 6, Part A.
Honda’s 1.5L turbo is the most fuel-efficient internal combustion engine on the market. Despite its small size, it offers outstanding fuel efficiency and performance scores. Its turbocharged engine delivers maximum power at low speeds, making it an excellent choice for urban commuters.