Head Coach Kyle Shanahan of the San Francisco 49ers | Image: Michael Zagaris / San Francisco 49ers / Getty Images
Four weeks ago, San Francisco 49ers coach Kyle Shanahan was involved in an accident near downtown Palo Alto. At the time Shanahan said only that the accident was his fault. But during a recent press conference he shared more details about the incident, including the fact that he had his Tesla's Autopilot engaged at the time. Shanahan was not passing the buck, however, saying it was his fault regardless of whether or not Autopilot was engaged.
"I've had Autopilot for nine years, so I'm pretty comfortable with it and, you know, who knows what happened when I turned around? Whether it malfunctioned or whether I knocked it off? That's somethi …
Researchers from the Southwest Research Institute (SwRI) have successfully developed an optimized spark-ignited hydrogen engine suitable for medium-duty commercial vehicles. As a form of internal combustion engine (ICE), the new engine behaves much more like a diesel engine than earlier hydrogen engines.
In other words, it is not a new kind of fuel-cell engine, but rather burns hydrogen inside cylinders using spark ignition. Just like a petrol engine, the new ICE produces mechanical propulsion using pistons.
“In addition to decades of developing medium- and heavy-duty engines, SwRI has some of the most extensive experience in the world developing and testing H2-ICEs for internal research, clients and industry demonstrations,” said Dr. Qilong Lu, a program manager in SwRI’s Powertrain Systems Engineering Department and one of the leads on this project.
“The engine was designed, constructed and rigorously tested at SwRI to ensure efficiency and performance,” Dr. Lu added.
Diesel-like torque hydrogen engine
“We began at the single-cylinder level, focusing on optimizing combustion and injection strategies,” Lu said. “From there, our team ramped up efforts to develop the full multi-cylinder engine, addressing key challenges such as pre-ignition, combustion stability and overall systems integration,” Lu added.
The attraction is that hydrogen contains no carbon, so burning it produces water rather than carbon dioxide. It also allows manufacturers to retain much of the familiar internal-combustion ecosystem: engines, transmissions, manufacturing equipment, servicing knowledge and supply chains.
The team also managed to deliver the new hydrogen ICE’s diesel-like torque using a turbocharger that forces more air into the engine. This allows it to burn more hydrogen and produce the strong low-speed torque needed to move loaded trucks.
The new engine also has improved airflow thanks to an innovative intake-port geometry allowing hydrogen to burn much faster than petrol and requiring different air movement inside the cylinder.
The engine also features larger intake valves and hydrogen-specific injectors to enable optimum fuel-to-air mixing within the cylinders. It also uses special software and calibrations to precisely manage injection, ignition, boost pressure and the air–fuel mixture.
Another wrinkle they had to overcome is safety. Hot engine surfaces or residual gases can ignite hydrogen before the spark fires, producing knocking, power loss or potentially engine damage.
Low-emissions but not zero
In terms of emissions, the engine produces what the team describes as “near-zero tailpipe CO₂.” While this is true in terms of the engine itself, the way in which the fuel hydrogen is produced matters here.
If produced from natural gas, rather than renewable electricity, CO₂ could remain high, all things considered. Also, hydrogen combustion can still produce nitrogen oxides, or NOx, because combustion heats nitrogen and oxygen from the air to very high temperatures.
It therefore isn’t literally a zero-emission engine and may require careful combustion control and exhaust after-treatment.
“The project brought together many areas and experts at the Institute to complete,” said Chris Bitsis, assistant director of SwRI’s Powertrain Systems Engineering Department, who oversees combustion research programs. “SwRI’s hydrogen combustion engine program is working every day to advance this technology and showcase its potential as a near-zero carbon emissions industry solution,” he added.
Wind propulsion company bound4blue has completed the installation of a 22-metre (72-foot) tall suction sail on the 292-foot (89-metre) cargo ship Na Hiro E Pae. This makes it the “first multipurpose vessel” worldwide to adopt a wind propulsion system. The unit was fitted at the Astilleros Armon Vigo yard in Spain for Greek shipping firm Société de Navigation des Australes SNA Tuha’a Pae.
“We hope Na Hiro E Pae leads the way for other ambitious shipping companies keen to unlock sustainable advantages,” said José Miguel Bermúdez.
Capable of carrying 200 passengers and 1,500 tonnes of supplies between Tahiti and the Austral Islands, the ship is expected to cut its energy consumption by 10 percent using the autonomous system alongside existing service from the Tuhaa Pae IV, which has operated on the route since 2012.
Delivering significant fuel savings
The installed technology, known as the eSail, yields sevenfold the thrust generated by an equally sized conventional rigid sail. This high efficiency allows a relatively small unit to deliver significant fuel savings without interfering with the fast loading and unloading operations required on multipurpose ships.
“bound4blue’s mechanically simple suction sail, producing up to seven times the propulsive force of a standard rigid sail of the same size, slots into a ‘green technology mix’ that includes engines capable of running on biofuel or e-fuel, electric POD propulsion, efficient waste management, and autonomy in fresh water supply,” highlighted the company in a press release.
The system functions by pulling airflow across a wide aerodynamic contour to assist the main engines. An autonomous vertical sail uses suction technology to draw air over this shape, creating propulsive thrust that decreases the mechanical burden on the vessel’s primary engines.
By pulling the air over its surface, the system prevents airflow separation that normally limits conventional sails. This aerodynamic effect allows the unit to generate far higher propulsive force relative to its physical surface area, directly lowering fuel usage and engine emissions.
“Multipurpose vessels have traditionally been seen as a challenging segment for wind power, due to the required flexibility of operations and related integration demands,” added Bermúdez.
Utilizing other green technologies
The compact nature of the eSail provides high force efficiency, allowing the vessel to maintain open deck space for cargo handling while utilizing wind energy.
The Na Hiro E Pae combines the suction sail with several other onboard green technologies. The ship features engines configured to burn biofuel or e-fuel as soon as local regional markets can supply them.
It also incorporates electric POD propulsion, efficient waste management systems, and autonomous fresh water supply capabilities to support its passenger and freight services.
“Sustainability was a key objective throughout the design process, and the eSAIL forms an important part of a wider package of technologies that will help us reduce energy consumption and environmental impact, while maintaining the reliable transport services our communities depend upon,” concluded Boris PIEL technical Director, SNA Tuha’a Pae Shipping Company.
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