Hybrid Electric Systems| Efficient Aeronautical Propulsion Alternative?

In recent years, hybrid systems or electric motors as aviation automobiles have been proposed as an alternative to conventional carbon-fueled engines. Environmental restrictions, economic factors, and flight safety all play a role in this.

Furthermore, trends in aircraft construction associated with increased levels of electrification result in a spike in the power of the volume of absorbed electrical energy onboard aircraft and helicopters.

The need for much more reasonable use of the present onboard energy considering the requirements of the target and auxiliary equipment, as well as the application of a specified route and flight mode also result in spike of power.

Air pollution is a prominent issue globally, and it is widely recognized as a danger to both economic development and public health. The World Health Organization (WHO) estimates that air pollution causes 4.2 million deaths per year.

Techniques that allow the measurement of air pollution-related indicators to track movement toward sustainable development objectives and that expand the knowledge base on the impacts of air pollution on health have recently seen significant advancements.

The air transport business has doubled in size every 20 years ever since the advent of jet engines, the fastest rate in the transportation sector, and expansion is likely to continue at a similar rate in the coming years. However, the impact of the project on the environment in terms of noise and pollution emissions has attracted public concern.

Furthermore, the anticipated financial benefits of higher energy efficiency have prompted the transportation industry to invest in alternative propulsion systems.

The aviation sector is responsible for a significant portion of greenhouse gas emissions, a concept in which internal combustion engines (ICEs) and electric motors (EMs) are merged in the propulsion system to improve vehicle efficiency and minimize impact is being investigated.

Emissions of carbon dioxide

CO2 emissions from diverse sectors such as electricity, buildings, land, transportation, and industry were 51.8 gigatons in 2019. Aviation accounted for 0.8 gigatons of CO2 emissions in the transportation sector, or 1.5 percent of overall emissions.

Governments all around the globe have initiated new projects and promoted eco-friendly technology to minimize carbon emissions from these sources.

The hybrid-electric propulsion system (HEPS) looks to be the most plausible alternative for more energy-efficient, cleaner, and quieter aeronautical propulsion since it combines the benefits of both traditional and all-electric propulsion systems.

Due to the higher number of components, hybrid-electric propulsion provides better operating flexibility. When compared to conventional propulsion systems, fuel and battery resources provide additional options for regulating the propulsion system at various stages of a mission while also reducing energy usage.

Nevertheless, it necessitates a rise in the required load during the design stage, as well as a boost in the operation’s complexity. To satisfy environmental regulations and decrease fuel consumption, proper control of electrical components and combustion is required.

Electrified Aircraft Propulsion Concepts

Electrified Propulsion

The utilization of electric power for aircraft propulsion is referred to as electrified propulsion. Propulsion might be entirely or partially electric. Other aircraft development plans refer to the usage of electric power for secondary systems like control surfaces and wing de-icing as “More electric” or “All electric”.

Hybrid Electric

Hybrid electric has two meanings in the context of aircraft, as explained below.

• One definition is the employment of two power sources to drive the fan (or propeller) on an aircraft, such as a turbine engine and an electric motor.

• Another definition is hybrid-electric propulsion, which is the use of several propulsion sources such as engines, turboelectric energy generation, fuel cells energy generation, or storage battery.

Turboelectric Propulsion

Turboelectric propulsion refers to on-air generated electric power for aircraft propulsion. Fully turboelectric propulsion implies that all turbine output is converted to electricity.

Turboelectric generating currently supplies electric power for secondary systems aboard airplanes. Partially turboelectric propulsion refers to a turbofan engine that uses a portion of the electric power generated for propulsion.

Hybrid Power Plants’ Contemporary Problems

The need to develop new, more modern onboard equipment systems is necessitated by the high demands placed on next-generation aircraft in terms of lower operating costs, economy, and fuel efficiency while retaining high flying performance.

All of this causes a slew of issues related to increasing power supply dependability, providing the requisite quality of generated energy, achieving a high level of control automation, and enhancing operational characteristics and other metrics.

Attributes of Hybrid Power Plant

Initiatives to employ an electric power plant are now seen mostly on tiny planes with a take-off weight of less than 1500 kg. The power supply is one of the most challenging components impeding the progress of electric aircraft.

The main shortcoming of power supply is their low specific capacity, which necessitates a hefty weight to achieve a reasonable range and length of the flight.

As a result, a hybrid is a viable alternative to both traditional and electric engines. Its use provides for lower fuel consumption, lower emissions, lower noise, and longer service life.

The employment of electric motors for propulsion with internal combustion engines or gas turbine engines for power production can drastically lower the aircraft’s weight while also allowing for new design concepts.

A hybrid aircraft’s architecture comprises combining a gas turbine power unit with a generator to create electricity, which is used to power electric motors with propellers or fans.

Conclusion

In short, due to a shortage of essential electric motors and power supplies, some companies are creating hybrid aircraft on which they test various hybrid installation alternatives to determine the best power source.

Hybrid propulsion technologies will also power passenger and freight airplanes. In this sense, it can be inferred that complete electrification will only affect super small aircraft in the next years.

Despite the challenges it faces, major companies of the industry are investing heavily, and the market is expected to grow at a significant rate.