scholarly journals Cascade Optimization Strategy for Aircraft and Air-Breathing Propulsion System Concepts

1997 ◽  
Vol 34 (1) ◽  
pp. 136-139 ◽  
Author(s):  
Surya N. Patnaik ◽  
Thomas M. Lavelle ◽  
Dale A. Hopkins ◽  
Rula M. Coroneos
Keyword(s):  
Propulsion System ◽  
Optimization Strategy ◽  
Air Breathing

scholarly journals Cascade optimization strategy for aircraft and air-breathing propulsion system concepts

1996 ◽  
Author(s):  
Surya Patnaik ◽  
Thomas Lavelle ◽  
Dale Hopkins ◽  
Rula Coroneos
Keyword(s):  
Propulsion System ◽  
Optimization Strategy ◽  
Air Breathing

scholarly journals Health-Conscious Optimization of Long-Term Operation for Hybrid PEMFC Ship Propulsion Systems

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3813
Author(s):  
Chiara Dall’Armi ◽  
Davide Pivetta ◽  
Rodolfo Taccani
Keyword(s):  
Polymer Electrolyte Membrane ◽  
Lithium Ion ◽  
Propulsion System ◽  
Optimization Strategy ◽  
Energy Management Strategy ◽  
Propulsion Systems ◽  
Hybrid Propulsion ◽  
Term Operation ◽  
Electrolyte Membrane

The need to decarbonize the shipping sector is leading to a growing interest in fuel cell-based propulsion systems. While Polymer Electrolyte Membrane Fuel Cells (PEMFC) represent one of the most promising and mature technologies for onboard implementation, they are still prone to remarkable degradation. The same problem is also affecting Lithium-ion batteries (LIB), which are usually coupled with PEMFC in hybrid powertrains. By including the combined degradation effects in an optimization strategy, the best compromise between costs and PEMFC/LIB lifetime could be determined. However, this is still a challenging yet crucial aspect, rarely addressed in the literature and rarely yet explored. To fill this gap, a health-conscious optimization is here proposed for the long-term minimization of costs and PEMFC/LIB degradation. Results show that a holistic multi-objective optimization allows a 185% increase of PEMFC/LIB lifetime with respect to a fuel-consumption-minimization-only approach. With the progressive ageing of PEMFC/LIB, the hybrid propulsion system modifies the energy management strategy to limit the increase of the daily operation cost. Comparing the optimization results at the beginning and the end of the plant lifetime, daily operation costs are increased by 73% and hydrogen consumption by 29%. The proposed methodology is believed to be a useful tool, able to give insights into the effective costs involved in the long-term operation of this new type of propulsion system.

Response of an Operational Turbofan Engine to a Simulated Nuclear Blast

1987 ◽  
Vol 109 (2) ◽  
pp. 121-129 ◽  
Author(s):  
M. G. Dunn ◽  
C. Padova ◽  
R. M. Adams
Keyword(s):  
Shock Waves ◽  
Transient Response ◽  
Incident Shock ◽  
Blast Waves ◽  
Propulsion System ◽  
Maximum Speed ◽  
Turbofan Engine ◽  
Air Breathing ◽  
Ludwieg Tube ◽  
Yaw Angle

This paper describes the results of a measurement program designed to determine the transient response of an air-breathing propulsion system to simulated nuclear blast waves. A Ludwieg-tube facility, incorporating a driver technique consisting of an activating chamber and a nonfrangible diaphragm, was used to create the required shock waves. Detailed measurements were performed at incident shock overpressures of approximately 6.9, 10.3, 13.8, and 17.2 kPa (1.0, 1.5, 2.0, and 2.5 psi). For each of these overpressures, data were obtained for engine speeds of 0, 80, 90, and 100 percent of maximum speed. Typical results are presented for distortion patterns at the fan face for both an extended bellmouth and a S-shaped inlet at either 0 or 20 deg yaw angle.

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