scholarly journals Fuel Cell Powered Electric Propulsion for HALE Aircraft

Author(s):  
John C. Bentz

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.


2018 ◽  
Vol 35 (2) ◽  
pp. 171-180 ◽  
Author(s):  
Yasin Şöhret

Abstract The aircraft industry, along with other industries, is considered responsible these days regarding environmental issues. Therefore, the performance evaluation of aircraft propulsion systems should be conducted with respect to environmental and ecological considerations. The current paper aims to present the ecological coefficient of performance calculation methodology for aircraft propulsion systems. The ecological coefficient performance is a widely-preferred performance indicator of numerous energy conversion systems. On the basis of thermodynamic laws, the methodology used to determine the ecological coefficient of performance for an aircraft propulsion system is parametrically explained and illustrated in this paper for the first time. For a better understanding, to begin with, the exergy analysis of a turbojet engine is described in detail. Following this, the outputs of the analysis are employed to define the ecological coefficient of performance for a turbojet engine. At the end of the study, the ecological coefficient of performance is evaluated parametrically and discussed depending on selected engine design parameters and performance measures. The author asserts the ecological coefficient of performance to be a beneficial indicator for researchers interested in aircraft propulsion system design and related topics.



2013 ◽  
Vol 393 ◽  
pp. 510-515
Author(s):  
Norhisyam Jenal ◽  
Wahyu Kuntjoro ◽  
Thomas Arthur Ward ◽  
Khairul Imran Sainan ◽  
Firdaus Mohamad

Combustion engines are increasingly being regarded as unsustainable in the long-term, because of their negative impact on the environment (e.g. pollution, green-house gas production, and global warming). This has generated worldwide interest in propulsion systems based on renewable alternative energy sources for the future. Fuel cell technology is a promising alternative power source because of their high specific energy, efficiency, and reliability. Hydrogen proton exchange membrane fuel cell (PEMFC) in particular produces zero carbon emissions by having only water vapor as the exhaust. Although there has been much research by automotive industries in developing fuel cell hybrid electric vehicles (FCHEV), fuel cell research for aircraft application is relatively new. Therefore, there is a pressing need for research related to development of aircraft fuel cell electric propulsion systems. Universiti Teknologi MARA (UiTM) is conducting static experiments on different configurations of fuel cell electric propulsion systems. The objective of this study is to understand the behavior of a PEMFC propulsion system under a ground-based static test. A 1 kW PEMFC was used as the main power source for a brushless DC motor electric propulsion system. The electrical characteristics, rotational speed, and thrust data were presented for two different electrical propellers. Analyses of the results were used to characterize the effectiveness of the fuel cell system and its balance of plant. The results were beneficial as a predictive method on defining the optimum electric propulsion system performance needed for future actual flight development.



Author(s):  
Junseop Jang

Submarines are weapons systems that have been proven to be useful in battle since World War I and have continued to improve the efficiency of propulsion systems in order to be used efficiently on the battlefield. In particular, countries that unable to utilize nuclear propulsion systems make efforts to increase the efficiency of Air Independent Propulsion systems, and typical examples are fuel cells, Stirling engines and MESMA. It is also expected that the development of new propulsion systems such as hydrogen-reformer fuel cells, metal-air fuel cell and direct combustion propulsion systems will continue, so the characteristics of these will be examined and the performance based on the published data be checked in this thesis.



2021 ◽  
Author(s):  
Je Ir Ryu ◽  
Austen Motily ◽  
Tonghun Lee ◽  
Riccardo Scarcelli ◽  
Sibendu Som ◽  
...  


MRS Bulletin ◽  
2005 ◽  
Vol 30 (8) ◽  
pp. 581-586 ◽  
Author(s):  
Robert W. Lashway

AbstractThe articles in this issue of MRS Bulletin highlight the enormous potential of fuel cells for generating electricity using multiple fuels and crossing a wide range of applications. Fuel cells convert chemical energy directly into electrical energy, and as a powergeneration module, they can be viewed as a continuously operating battery.They take in air (or pure oxygen, for aerospace or undersea applications) and hydrocarbon or hydrogen fuel to produce direct current at various outputs. The electrical output can be converted and then connected to motors to generate much cleaner and more fuelefficient power than is possible from internal combustion engines, even when combined with electrical generators in today's hybrid engines. The commercialization of these fuel cell technologies is contingent upon additional advances in materials science that will suit the aggressive electrochemical environment of fuel cells (i.e., both reducing an oxidizing) and provide ionic and electrical conductance for thousands of hours of operation.



2019 ◽  
Vol 7 (6) ◽  
pp. 168
Author(s):  
Hyeonmin Jeon ◽  
Jongsu Kim ◽  
Kyoungkuk Yoon

In the case of the electric propulsion system on the vessel, Diode Front End (DFE) rectifiers have been applied for large-sized ships and Active Front End (AFE) rectifiers have been utilized for small and medium-sized ships as a part of the system. In this paper, we design a large electric propulsion ship system using AFE rectifier with the proposed phase angle detector and verify the feasibility of the system by simulation. The phase angle derived from the proposed phase angle detection method is applied to the control of the AFE rectifier instead of the zero-crossing method used to detect the phase angle in the control of the conventional AFE rectifier. We compare and analyze the speed control, Direct Current (DC)-link voltage, harmonic content and measurement data of heat loss by inverter switch obtained from the simulation of the electric propulsion system with the 24-pulse DFE rectifier, the conventional AFE rectifier, and the proposed AFE rectifier. As a result of the simulation, it was confirmed that the proposed AFE rectifier derives a satisfactory result similar to that of a 24-pulse DFE rectifier with a phase shifting transformer installed according to the speed load of the ship, and it can be designed and applied as a rectifier of a large-sized vessel.



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