Browsing by Author "Balaghi Enalou, Hossein"

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    Application of probabilistic principles to set-based design for the optimisation of a hybrid-electric propulsion system
    (IOP, 2022-02-15) Spinelli, Andrea; Anderson, Luchien; Balaghi Enalou, Hossein; Zaghari, Bahareh; Kipouros, Timoleon; Laskaridis, Panagiotis
    Current research in hybrid-electric aircraft propulsion has outlined the increased complexity in design when compared with traditional propulsion. However, current design methodologies rely on aircraft-level analysis and do not include the consideration of the impact of new technologies and their uncertainty. This can be a key factor for the development of future hybrid-electric propulsion systems. In this paper, we present a methodology for exploring the design space using the principles of Set-Based Design, which incorporates probabilistic assessment of requirements and multidisciplinary optimisation with uncertainty. The framework can explore every design parameter combination using a provided performance model of the system under design and evaluate the probability of satisfying a minimum required figure of merit. This process allows to quickly discard configurations incapable of meeting the goals of the optimiser. A multidisciplinary optimiser then is used to obtain the best points in each surviving configuration, together with their uncertainty. This information is used to discard undesirable configurations and build a set of Pareto optimal solutions. We demonstrate an early implementation of the framework for the design of a parallel hybrid-electric propulsion system for a regional aircraft of 50 seats. We achieve a considerable reduction to the required function evaluations and optimisation run time by avoiding the ineffective areas of the design space but at the same time maintaining the optimality potential of the selected sets of design solutions.
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    Application of probabilistic set-based design exploration on the energy management of a hybrid-electric aircraft
    (MDPI, 2022-03-08) Spinelli, Andrea; Balaghi Enalou, Hossein; Zaghari, Bahareh; Kipouros, Timoleon; Laskaridis, Panagiotis
    The energy management strategy of a hybrid-electric aircraft is coupled with the design of the propulsion system itself. A new design space exploration methodology based on Set-Based Design is introduced to analyse the effects of different strategies on the fuel consumption, NOx and take-off mass. Probabilities are used to evaluate and discard areas of the design space not capable of satisfying the constraints and requirements, saving computational time corresponding to an average of 75%. The study is carried on a 50-seater regional turboprop with a parallel hybrid-electric architecture. The strategies are modelled as piecewise linear functions of the degree of hybridisation and are applied to different mission phases to explore how the strategy complexity and the number of hybridised segments can influence the behaviour of the system. The results indicate that the complexity of the parametrisation does not affect the trade-off between fuel consumption and NOx emissions. On the contrary, a significant trade-off is identified on which phases are hybridised. That is, the least fuel consumption is obtained only by hybridising the longest mission phase, while less NOx emissions are generated if more phases are hybridised. Finally, the maximum take-off mass was investigated as a parameter, and the impact to the trade-off between the objectives was analysed. Three energy management strategies were suggested from these findings, which achieved a reduction to the fuel consumption of up to 10% and a reduction to NOx emissions of up to 15%.
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    Minimising the effect of degradation of fuel cell stacks on an integrated propulsion architecture for an electrified aircraft
    (IEEE, 2022-07-07) Zhou, Tianzhi; Balaghi Enalou, Hossein; Pontika, Evangelia; Zaghari, Bahareh; Laskaridis, Panagiotis
    Proton Exchange Membrane Fuel Cells (PEMFC) are receiving interest as an electrical source of energy for aircraft propulsion electrification. However, their implementation challenges such as durability, reliability, and the dynamic behaviour of Fuel Cells (FCs) in an integrated hybrid propulsion system have not been fully explored. Currently, most commercial PEMFC stacks have maximum power close to 150kW. To achieve higher power required for aviation, these stacks can be connected in series and parallel to achieve high voltage required for propulsion. Poor design procedure of cells and stacks can cause variation between the stacks resulting in failure and fast degradation of the connected stacks. In this paper the impact of voltage and current drop of one stack, which could be caused by changes in the fuel cell’s individual axillary parts, degradation of the cells within the stack, or faults in the connections and distribution is explored. Upon exploring different configurations, it is found that the arrangements of FC stacks connections could help in reducing the impact of voltage and current variations due to degradation in each stacks. The imbalance stack performance and its effects on the whole energy storage system performance is not fully explored before. It is important to conduct quantitative analysis on these issues before the PEMFC system can be implemented.
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    System architectures for thermal management of hybrid-electric aircraft - FutPrInt50
    (IOP, 2022-02-15) Affonso Jr., Walter; Tavares, Renata T.; Barbosa, Felipe R.; Gandolfi, Ricardo; dos Reis, Ricardo J. N.; da Silva, Carlos R. I.; Kipouros, Timoleon; Laskaridis, Panagiotis; Balaghi Enalou, Hossein; Chekin, Andrei; Kukovinets, Aleksey; Gubernatorov, Konstantin; Ravikovich, Yury; Ivanov, Nikolay; Ponyaev, Leonid; Holobtsev, Dmitry
    Electric and Hybrid-Electric Aircraft (HEA) propulsion system designs shall bring challenges at aircraft and systems level, mainly in propulsion, electric and thermal management systems (TMS). The electrification of the propulsion system relies on large and high-power electrical equipment (e.g., electrical motors, converters, power electronics, batteries, and others) that dissipate heat at a rate at least one order of magnitude higher than conventional propulsion aircraft systems. As a result, high impacts on weight, drag and power consumption of the TMS/cooling systems at the aircraft level are expected. This paper proposes potential technologies to perform the thermal management of future electric and HEA, in the context of FUTPRINT50 project. For each technology, relevant aspects such as its integration to aircraft, safety, operational and maintenance impacts, certification, technologies readiness level (TRL) and the latest research works are analysed. A quantitative comparison of the several technologies is also proposed considering weight, volume, electric power consumption, pneumatic air flow and cooling air flow per cooling effect. Lastly, we present a set of potential TMS architectures for HEA.