scholarly journals Electric Aircraft Propulsion

2021 ◽  
Vol 51 (4) ◽  
pp. 49-66
Author(s):  
Adam Kozakiewicz ◽  
Tomasz Grzegorczyk
Keyword(s):  
Energy Density ◽  
Electric Propulsion ◽  
Electrical Power ◽  
Global Scale ◽  
Propulsion Systems ◽  
Power Sources ◽  
Aerospace Applications ◽  
Flight Operations ◽  
Electric Aircraft ◽  
Aircraft Propulsion

Abstract This paper presents the state of the art in electric aircraft propulsion systems. The necessary reduction of greenhouse gas emissions on the global scale forces aviation engineers to search for ‘green’ solutions. Electric aircraft propulsion is a potential and relatively intuitive choice for a reduction of emissions in flight operations. This paper showcases four architectures of aircraft propulsion systems being now considered to utilise the advantages of electric propulsion with commercially profitable operating range and payload capabilities. One of the largest technological obstacles to the widespread use of electric propulsion in aviation is the low energy density of modern electric batteries. This paper presents the types of power supply which may achieve an energy density above the minimum threshold of 500 Wh/kg, and alternative onboard electrical power sources. The paper also shows novel designs of electric motors intended for aerospace applications. The final sections of this paper shows the implemented projects of aircraft with electric propulsion and the electric aircraft propulsion research projects underway around the world.

scholarly journals Voltage synchronisation for hybrid-electric aircraft propulsion systems

2021 ◽  
pp. 1-20
Author(s):  
K. Ibrahim ◽  
S. Sampath ◽  
D. Nalianda
Keyword(s):  
Electrical Power ◽  
Potential Method ◽  
Propulsion System ◽  
System Level ◽  
Flux Variation ◽  
Power Sources ◽  
Electric Aircraft ◽  
Hybrid Electric ◽  
Aircraft Propulsion System ◽  
Aircraft Propulsion

Abstract Increasing demand for commercial air travel is projected to have additional environmental impact through increased emissions from fuel burn. This has necessitated the improvement of aircraft propulsion technologies and proposal of new concepts to mitigate this impact. The hybrid-electric aircraft propulsion system has been identified as a potential method to achieve this improvement. However, there are many challenges to overcome. One such challenges is the combination of electrical power sources and the best strategy to manage the power available in the propulsion system. Earlier methods reviewed did not quantify the mass and efficiency penalties incurred by each method, especially at system level. This work compares three power management approaches on the basis of feasibility, mass and efficiency. The focus is on voltage synchronisation and adaptation to the load rating. The three methods are the regulated rectification, the generator field flux variation and the buck-boost. This comparison was made using the propulsion system of the propulsive fuselage aircraft concept as the reference electrical configuration. Based on the findings, the generator field flux variation approach appeared to be the most promising, based on a balance of feasibility, mass and efficiency, for a 2.6MW system.

scholarly journals Fuel Cell Powered Electric Propulsion for HALE Aircraft

1992 ◽  
Author(s):  
John C. Bentz
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Electric Propulsion ◽  
Environmental Pollutants ◽  
Electrical Energy ◽  
Propulsion System ◽  
Energy Sources ◽  
Propulsion Systems ◽  
Aircraft Propulsion System ◽  
Aircraft Propulsion

Electrical energy sources offer some interesting possibilies for aircraft propulsion. Of particular interest are electric propulsion systems developed for aircraft that are designed for high altitude, long endurance (HALE) missions. This class of aircraft would greatly benefit from an aircraft propulsion system which minimizes thermal energy rejection and environmental pollutants. Electric propulsion systems may prove viable for the HALE mission, if reliable energy sources can be developed that are both fuel and weight efficient. Fuel cells are a possible energy source. This paper discusses the thermodynamic cyclic analysis of a fuel cell powered electric propulsion system. In particular, phosphoric acid and polymer electrolyte fuel cells are evaluated as possible energy sources.

Transient Analysis of an Innovative Cycle Integrating a SOFC and a Turbogenerator for Electric Propulsion

2017 ◽  
Author(s):  
Venkata Adithya Chakravarthula ◽  
Rory A. Roberts
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Hybrid System ◽  
Electric Propulsion ◽  
Transient Analysis ◽  
Electrical Power ◽  
Combustion Process ◽  
Operating Conditions ◽  
Efficiency Gains ◽  
Aerospace Applications

Gas turbine technology for aerospace applications is approaching limits in efficiency gains as efficiency gains today occur in very small increments. One limitation in conventional gas turbine technology is the combustion process, which destroys most of the exergy in the cycle. To address this limitation in a traditional Brayton power cycle, a hybrid system which is integrating a Solid Oxide Fuel Cell (SOFC) and gas turbine is developed. Hybrid systems involving fuel cells have better efficiencies than conventional power generation systems. The combination of a SOFC with a gas turbine has shown higher efficiencies than conventional gas turbine systems due to the reduction of exergy destruction in the heat addition process. A one-dimensional dynamic model of a SOFC is integrated in a SOFC-Combustor configuration with a gas turbine to develop efficient electrical power generation for aviation applications. The SOFC–Combustor configuration is an unique concept for reducing system weight, volume, complexity, and response time, which are important attributes for aerospace systems. SOFC-Combustor model was developed based on first principles with detailed modeling of the internal steam reformer, electrochemical and thermodynamics of the SOFC included. The overall purpose of this paper is to analyze the performance of the hybrid SOFC system for high altitude operation for both on-design and off-design operating conditions. Steady-state analysis for cruise condition performed to calculate the respective mission efficiencies. By determining the operating efficiencies of the system, gravimetric comparisons including fuel are performed for alternative power cycles for given flight durations. Transient analysis is performed to understand the behavior in the SOFC temperatures and hybrid system with sudden perturbations to the system (rapid throttle changes, environment changes).

scholarly journals A Review of Compressed Air Engine in the Vehicle Propulsion System

2021 ◽  
Vol 15 (4) ◽  
pp. 215-226
Author(s):  
Michal Korbut ◽  
Dariusz Szpica
Keyword(s):  
Energy Density ◽  
Internal Combustion Engines ◽  
Low Energy ◽  
Compressed Air ◽  
Combustion Engines ◽  
Economic Aspects ◽  
Propulsion Systems ◽  
Power Sources ◽  
Vehicle Propulsion ◽  
Alternative Power

Abstract Engines powered by compressed air as a source of propulsion are known for many years. Nevertheless, this type of drive is not commonly used. The main reason for not using commonly is the problem with the low energy density of the compressed air. They offer a number of advantages, primarily focusing on the possibility of significantly lowering the emissions of the engine. Their emissivity mainly depends on the method of obtaining compressed air. This also has an impact on the economic aspects of the drive. Currently there are only a few, ready to implement, compressed air powered engine solutions available on the market. A major advantage is the ability to convert internal combustion engines to run with compressed air. The study provides a literature review of solutions, focusing on a multifaceted analysis of pneumatic drives. Increasing vehicle approval requirements relating to their emissions performance are encouraging for the search of alternative power sources. This creates an opportunity for the development of unpopular propulsion systems, including pneumatic engines. Analysing the works of some researchers, it is possible to notice a significant increase in the efficiency of the drive, which may contribute to its popularisation.

Micropropulsion Development at the ARC Seibersdorf Research

2006 ◽  
Author(s):  
Carsten Arthur Scharlemann ◽  
Martin Tajmar
Keyword(s):  
Hydrogen Peroxide ◽  
Electric Propulsion ◽  
Specific Impulse ◽  
Electrical Power ◽  
Preliminary Test ◽  
Small Mass ◽  
Space Missions ◽  
Propulsion Systems ◽  
Future Space ◽  
Chemical Propulsion

The increasing application of micro-satellites (from 10 kg up to 100 kg) for a rising number of various missions demands the development of new miniaturized propulsion systems. Micro-satellites have special requirements for the propulsion system such as small mass, reduced volume, and very stringent electrical power constraints. Existing propulsion systems often can not satisfy these requirements. The Space Propulsion Department of the ARC Seibersdorf research dedicated itself to the development and test of various micropropulsion systems for present and future space missions. The portfolio of the systems under development includes electrical and chemical propulsion systems. The covered thrust and specific impulse of the developed propulsion systems ranges from 1μN to 1N and 500 s to 8000 s respectively. Based on the large experience obtained over several decades in the development of Field Emission Electric Propulsion systems (FEEP), several microstructured FEEPs have been developed. The design of these systems is presented as well as preliminary test results and a summarization of the experience obtained during the process of miniaturizing such systems. The development of miniaturized chemical propulsion systems includes a bipropellant and a monopropellant thruster. The bipropellant thruster constitutes the smallest existing 1N thruster utilizing hydrogen peroxide. The thruster system consists of two micopumps for the propellant feed and a microturbine to generate the power for operating the pumps. The monopropellant thruster is a derivative of the bipropellant thruster. It offers a lower specific impulse than the bipropellant system but due to its reduced system complexity it represents also a promising candidate for several future space missions. Both systems utilize rocket grade hydrogen peroxide (green propellant), which is decomposed with the help of an advanced monolithic catalyst. The present paper discusses the design methods and the physical limitations of such chemical propulsion systems with regard to their miniaturization and summarizes their performance evaluation.

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