Synergistic hybrid-electric liquid natural gas drone: S.H.I.E.L.D

2020 ◽  
Vol 92 (5) ◽  
pp. 757-768 ◽  
Author(s):  
Thierry Sibilli ◽  
Capucine Senne ◽  
Hugo Jouan ◽  
Askin T. Isikveren ◽  
Sabrina Ayat
Keyword(s):  
Thermal Management ◽  
Synergistic Effects ◽  
Energy System ◽  
Sensitivity Study ◽  
Coolant Temperature ◽  
Electrical System ◽  
Content Type ◽  
Electric Aircraft ◽  
Aircraft Performance ◽  
Hybrid Electric

Purpose With the objective to assess potentially performant hybrid-electric architectures, this paper aims to present an aircraft performance level evaluation, in terms of range and payload, of the synergies between a hybrid-electric energy system configuration and a cryogenic fuel system. Design/methodology/approach An unmanned aerial vehicle (UAV) is modeled using an aircraft performance tool, modified to take into account the hybrid nature of the system. The fuel and thermal management systems are modeled looking to maximize the synergistic effects. The electrical system is defined in series with the thermal engine and the performance, in terms of weight and efficiency, are tracked as a function of the cooling temperature. Findings The results show up to a 46 per cent increase in range and up to 7 per cent gain on a payload with a reference hybrid-electric aircraft that uses conventional drop-in JP-8 fuel. The configuration that privileges a reduction in mass of the electric motors by taking advantage of the cryogenic coolant temperature shows the highest benefits. A sensitivity study is also presented showing the dependency on the modeling capabilities. Practical implications The synergistic combination of a cryogenic fuel and the additional heat sources of a hybrid-electric system with a tendency to higher electric component efficiency or reduced weight results in a considerable performance increase in terms of both range and payload. Originality/value The potential synergies between a cryogenic fuel and the electrical system of a hybrid-electric aircraft seem clear; however, at the present, no detailed performance evaluation at aircraft level that includes the fuel, thermal management and electric systems, has been published.

Integrated Propulsive and Thermal Management System Design for Optimal Hybrid Electric Aircraft Performance

2020 ◽  
Author(s):  
Philip C. Abolmoali ◽  
Adam B. Donovan ◽  
Soumya S. Patnaik ◽  
Patrick McCarthy ◽  
Dominic Dierker ◽  
...  
Keyword(s):  
System Design ◽  
Thermal Management ◽  
Management System ◽  
Thermal Management System ◽  
Electric Aircraft ◽  
Aircraft Performance ◽  
Hybrid Electric

Advanced aircraft performance analysis

2018 ◽  
Vol 90 (4) ◽  
pp. 627-638 ◽  
Author(s):  
Marc Immer ◽  
Philipp Georg Juretzko
Keyword(s):  
Performance Analysis ◽  
Design Process ◽  
Performance Optimization ◽  
Electric Propulsion ◽  
Vertical Plane ◽  
Aircraft Design ◽  
Efficient Design ◽  
Content Type ◽  
Aircraft Performance ◽  
Hybrid Electric

Purpose The preliminary aircraft design process comprises multiple disciplines. During performance analysis, parameters of the design mission have to be optimized. Mission performance optimization is often challenging, especially for complex mission profiles (e.g. for unmanned aerial vehicles [UAVs]) or hybrid-electric propulsion. Therefore, the purpose of this study is to find a methodology that supports aircraft performance analysis and that is applicable to complex profiles and to novel designs. Design/methodology/approach As its core element, the developed method uses a computationally efficient C++ software “Aircraft Performance Program” (APP), which performs a segment-based mission computation. APP performs a time integration of the equations of motion of a point mass in the vertical plane. APP is called via a command line interface from a flexible scripting language (Python). On top of APP’s internal radius of action optimization, state-of-the-art optimization packages (SciPy) are used. Findings The application of the method to a conventional climb schedule shows that the definition of the top of climb has a significant influence on the resulting optimum. Application of the method to a complex UAV mission optimization, which included maximizing the radius of action, was successful. Low computation time enables to perform large parametric studies. This greatly improves the interpretation of the results. Research limitations/implications The scope of the paper is limited to the methodology that allows for advanced performance analysis at the conceptual and preliminary design stages with an emphasis on novel propulsion concepts. The methodology is developed using existing, validated methods, and therefore, this paper does not contain comprehensive validation. Other disciplines, such as cost analysis, life-cycle assessment or market analysis, are not considered. Practical implications With the proposed method, it is possible to obtain not only the desired optimum mission performance but also off-design performance of the investigated design. A thorough analysis of the mission performance provides insight into the design’s capabilities and shortcomings, ultimately aiding in obtaining a more efficient design. Originality/value Recent developments in the area of hybrid or hybrid-electric propulsion systems have shown the need for performance computation tools aiding the related design process. The presented method is especially valuable when novel design concepts with complex mission profiles are investigated.

scholarly journals Optimal energy management for hybrid-electric aircraft

2020 ◽  
Vol 92 (6) ◽  
pp. 851-861 ◽  
Author(s):  
José Pedro Soares Pinto Leite ◽  
Mark Voskuijl
Keyword(s):  
Power Systems ◽  
Energy Management ◽  
Gas Turbines ◽  
Weight System ◽  
Content Type ◽  
Optimal Energy ◽  
Variable Weight ◽  
Electric Aircraft ◽  
Optimal Energy Management ◽  
Hybrid Electric

Purpose In recent years, increased awareness on global warming effects led to a renewed interest in all kinds of green technologies. Among them, some attention has been devoted to hybrid-electric aircraft – aircraft where the propulsion system contains power systems driven by electricity and power systems driven by hydrocarbon-based fuel. Examples of these systems include electric motors and gas turbines, respectively. Despite the fact that several research groups have tried to design such aircraft, in a way, it can actually save fuel with respect to conventional designs, the results hardly approach the required fuel savings to justify a new design. One possible path to improve these designs is to optimize the onboard energy management, in other words, when to use fuel and when to use stored electricity during a mission. The purpose of this paper is to address the topic of energy management applied to hybrid-electric aircraft, including its relevance for the conceptual design of aircraft and present a practical example of optimal energy management. Design/methodology/approach To address this problem the dynamic programming (DP) method for optimal control problems was used and, together with an aircraft performance model, an optimal energy management was obtained for a given aircraft flying a given trajectory. Findings The results show how the energy onboard a hybrid fuel-battery aircraft can be optimally managed during the mission. The optimal results were compared with non-optimal result, and small differences were found. A large sensitivity of the results to the battery charging efficiency was also found. Originality/value The novelty of this work comes from the application of DP for energy management to a variable weight system which includes energy recovery via a propeller.

Early Design Stage Evaluation of Thermal Performance of Battery Heat Acquisition System of a Hybrid Electric Aircraft

2020 ◽  
Vol 17 (2) ◽  
Author(s):  
Malcolm Macdonald ◽  
S. Ravi Annapragada ◽  
Aritra Sur ◽  
Reza Mahmoudi ◽  
Charles Lents ◽  
...  
Keyword(s):  
Thermal Management ◽  
High Efficiency ◽  
Electric Energy ◽  
Acquisition System ◽  
Design Stage ◽  
Early Design ◽  
Early Design Stage ◽  
Electric Aircraft ◽  
Hybrid Electric ◽  
Management Approaches

Abstract The electric energy and power storage, conversion and distribution (ESC&D) system of a hybrid electric aircraft, even at high efficiency, will reject significant heat at relatively low temperature. Thermal management systems (TMSs) can add excessive weight (heat exchangers and pumps) and impose excessive parasitic power consumption (pumps and fans) and drag (engine fan stream air and ram air) on the aircraft. Thus, effective low-weight thermal management of the ESC&D system is critical to realizing the potential benefits of a hybrid electric aircraft. This paper carries out early design stage benchmarking and evaluation of various thermal management approaches for the battery heat acquisition system of a hybrid electric aircraft. It is shown that the battery heat acquisition system based on state-of-the-art automotive electric vehicle design may be a third of the weight of the battery itself. Alternative approaches discussed here have the promise of reducing this weight by more than 60%.

scholarly journals Design and Optimization of Ram Air-Based Thermal Management Systems for Hybrid-Electric Aircraft

Aerospace ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 3
Author(s):  
Hagen Kellermann ◽  
Michael Lüdemann ◽  
Markus Pohl ◽  
Mirko Hornung
Keyword(s):  
Thermal Management ◽  
Sensitivity Analyses ◽  
Management Systems ◽  
Dimensional System ◽  
System Sensitivity ◽  
Design And Optimization ◽  
Fuel Burn ◽  
Electric Aircraft ◽  
Power Split ◽  
Hybrid Electric

Ram air-based thermal management systems (TMS) are investigated herein for the cooling of future hybrid-electric aircraft. The developed TMS model consists of all components required to estimate the impacts of mass, drag, and fuel burn on the aircraft, including the heat exchangers, coldplates, ducts, pumps, and fans. To gain a better understanding of the TMS, one- and multi-dimensional system sensitivity analyses were conducted. The observations were used to aid with the numerical optimization of a ram air-based TMS towards the minimum fuel burn of a 180-passenger short-range turboelectric aircraft with a power split of up to 30% electric power. The TMS was designed for the conditions at the top of the climb. For an aircraft with the maximum power split, the additional fuel burn caused by the TMS is 0.19%. Conditions occurring at a hot-day takeoff represent the most challenging off-design conditions for TMS. Steady-state cooling of all electric components with the designed TMS is possible during a hot-day takeoff if a small puller fan is utilized. Omitting the puller fan and instead oversizing the TMS is an alternative, but the fuel burn increase on the aircraft level grows to 0.29%.

Characterization of High-Density Aircraft Electronic and Thermal Management Systems

2021 ◽  
Author(s):  
Joshua Kasitz ◽  
David Huitink
Keyword(s):  
Thermal Management ◽  
Electronic Devices ◽  
Electronic Cooling ◽  
High Density ◽  
Management Systems ◽  
Local Cooling ◽  
Cooling Systems ◽  
Electric Aircraft ◽  
Hybrid Electric ◽  
Electric Powertrains

Abstract As aircrafts move toward electrification with the research and development of hybrid-electric powertrains, the focus has begun to shift to the reliability challenges of electronic devices subject to flight. Electronic components in aircraft applications are subject to two main sources of failure inducing stresses: the thermomechanical stresses that develop due to unequal coefficients of thermal expansion of different materials used in the components, and the stresses developing due to shocks and vibrations during flight as well as landing and takeoff. While the challenge of dealing with CTE mismatches is applicable to electronic devices in general, the ambient conditions surrounding the aircraft in flight, combined with weight and space constrains add significant logistical issues to any cooling mechanism. This paper will focus on the environmental influence on the thermal dissipation profile that will ultimately lead to CTE failures. The push toward more-electric-aircraft (MEA) increases the need to further advance the power and versatility of electronic cooling systems to adequately manage high density power modules, which until recently were not highly incorporated in aviation systems. Environmental conditions will play a large role in the design space and limitations of potential cooling solutions and will dictate the effectiveness of current thermal management systems. In arising scenarios where high-density electronics cannot be contained within a pressurized and temperature-controlled cabin, drastic pressure and temperature swings, facilitated by the external environment, will lead to an extra source of fluctuating stress on the cooling system. This is likely to be a prevalent factor in hybrid-electric and all-electric powertrains as requiring environmental controlled spaces for major components could be limited. This can easily be seen in current attempts to examine and redesign local cooling systems for electric motors in aviation. Representing just one of the major cooling requirements on an electric aircraft, motor cooling systems demonstrate the universal cooling problems limiting all aspects of the powertrains system. This paper aims to define the impact of the changing environment, through a flight profile of an aircraft, on high density electronic cooling systems by assessing the potential system stressors that significantly impact performance, efficiency, and reliability of the cooling systems. It will also utilize local cooling efforts for motors to relate the general problems to applicable design considerations that must be understood to further the performance capability of the overall propulsion system.

Hierarchical Multi-Timescale Energy Management for Hybrid-Electric Aircraft

2020 ◽  
Author(s):  
Wenqing Wang ◽  
Justin P. Koeln
Keyword(s):  
Power Systems ◽  
Constraint Satisfaction ◽  
State Constraint ◽  
Computationally Efficient ◽  
Hybrid Power Systems ◽  
Electrical Systems ◽  
Electric Aircraft ◽  
Aircraft Performance ◽  
Hybrid Electric ◽  
Upper Level

Abstract Hybrid-electric aircraft represent an important step in the transition from conventional fuel-based propulsion to fully-electric aircraft. For hybrid power systems, overall aircraft performance and efficiency highly depend on the coordination of the fuel and electrical systems and the ability to effectively control state and input trajectories at the limits of safe operation. In such a safety-critical application, the chosen control strategy must ensure the closed-loop system adheres to these operational limits. While hierarchical Model Predictive Control (MPC) has proven to be a computationally efficient approach to coordinated control of complex systems across multiple timescales, most formulations are not supported by theoretical guarantees of actuator and state constraint satisfaction. To provide guaranteed constraint satisfaction, this paper presents set-based hierarchical MPC of a 16 state hybrid-electric aircraft power system. Within the proposed two-level vertical hierarchy, the long-term control decisions of the upper-level controller and the short-term control decisions of the lower-level controller are coordinated through the use of waysets. Simulation results show the benefits of this coordination in the context of hybrid-electric aircraft performance and demonstrate the practicality of applying set-based hierarchical MPC to complex multi-timescale systems.

Sign in / Sign up

Export Citation Format

Share Document