Future aircraft concepts and design methods

2021 ◽  
pp. 1-33
Author(s):  
Robert A. McDonald ◽  
Brian J. German ◽  
T. Takahashi ◽  
C. Bil ◽  
W. Anemaat ◽  
...  
Keyword(s):  
Collaborative Design ◽  
Electric Propulsion ◽  
Travel Demand ◽  
Ghg Emissions ◽  
Aircraft Design ◽  
General Aviation ◽  
Civil Aviation ◽  
Joint Decision ◽  
Trade Offs ◽  
Multidisciplinary Design Optimisation

Abstract With an annual growth in travel demand of about 5% globally, managing the environmental impact is a challenge. In 2019, the International Civil Aviation Organisation (ICAO) issued emission reduction targets, including well-to-wake greenhouse gas (GHG) emissions reduced at least 50% from 2005 levels by 2050. This discusses several technologies from an aircraft design perspective that can contribute to achieving these targets. One thing is certain: aircraft will look different in the future. The Transonic Truss-Braced Wing and Flying V configurations are promising significant efficiency improvements over conventional configurations. Electric propulsion, in various architectures, is becoming a feasible option for general aviation and commuter aircraft. It will be a growing field of aviation with zero-emissions flight and opportunities for special missions. Lastly, this paper discusses methods and design processes that include all relevant disciplines to ensure that the aircraft is optimised as a complete system. While empirical methods are essential for initial design, Multidisciplinary Design Optimisation (MDO) incorporates models and simulations integrated in an optimisation environment to capture critical trade-offs. Concurrent design places domain experts in one site to facilitate collaboration, interaction, and joint decision-making, and to ensure all disciplines are equally considered. It is supported by a Collaborative Design Facility (CDF), an information technology facility with connected hardware and software tools for design analysis.

scholarly journals Wing Structural Model for Overall Aircraft Design of Distributed Electric Propulsion General Aviation and Regional Aircraft

Aerospace ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 5
Author(s):  
Raquel Alonso Castilla ◽  
Florent Lutz ◽  
Joël Jézégou ◽  
Emmanuel Bénard
Keyword(s):  
Conceptual Design ◽  
Electric Propulsion ◽  
Structural Model ◽  
Aircraft Design ◽  
General Aviation ◽  
The European Union ◽  
Analytical Methodology ◽  
Conceptual Design Phase ◽  
Aerodynamic Properties ◽  
Structural Mass

In the context of reducing the environmental footprint of tomorrow’s aviation, Distributed Electric Propulsion (DEP) has become an increasingly interesting concept. With the strong coupling between disciplines that this technology brings forth, multiple benefits are expected for the overall aircraft design. These interests have been observed not only in the aerodynamic properties of the aircraft but also in the structural design. However, current statistical models used in conceptual design have shown limitations regarding the benefits and challenges coming from these new design trends. As for other methods, they are either not adapted for use in a conceptual design phase or do not cover CS-23 category aircraft. This paper details a semi-analytical methodology compliant with the performance-based certification criteria presented by the European Union Aviation Safety Agency (EASA) to predict the structural mass breakdown of a wing. This makes the method applicable to any aircraft regulated by EASA CS-23. Results have been validated with the conventional twin-engine aircraft Beechcraft 76, the innovative NASA X-57 Maxwell concept using DEP, and the commuter aircraft Beechcraft 1900.

scholarly journals Computational Study of the Propeller Position Effects in Wing-Mounted, Distributed Electric Propulsion with Boundary Layer Ingestion in a 25 kg Remotely Piloted Aircraft

Drones ◽  
2021 ◽  
Vol 5 (3) ◽  
pp. 56
Author(s):  
José Serrano Cruz ◽  
Andrés Tiseira ◽  
Luis García-Cuevas ◽  
Pau Varela
Keyword(s):  
Boundary Layer ◽  
Electric Propulsion ◽  
Computational Study ◽  
Bending Moment ◽  
Vertical Position ◽  
Position Effects ◽  
Foreign Object Damage ◽  
Trade Offs ◽  
Remotely Piloted Aircraft ◽  
Interesting Approach

Distributed electric propulsion and boundary layer ingestion are two attractive technologies to reduce the power consumption of fixed wing aircraft. Through careful distribution of the propulsive system elements, higher aerodynamic and propulsive efficiency can be achieved, as well as a lower risk of total loss of aircraft due to foreign object damage. When used on the wing, further reductions of the bending moment on the wing root can even lead to reductions of its structural weight, thus mitigating the expected increase of operating empty weight due to the extra components needed. While coupling these technologies in fixed-wing aircraft is being actively studied in the big aircraft segment, it is also an interesting approach for increasing the efficiency even for aircraft with maximum take-off masses as low as 25 kg, such as the A3 open subcategory for civil drones from EASA. This paper studies the effect of changing the propellers’ position in the aerodynamic performance parameters of a distributed electric propulsion with boundary layer ingestion system in a 25 kg fixed-wing aircraft, as well as in the performance of the propellers. The computational results show the trade-offs between the aerodynamic efficiency and the propeller efficiency when the vertical position is varied.

scholarly journals Spatially Explicit Assessment of Suitable Conditions for the Sustainable Production of Aviation Fuels in Brazil

Land ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 705
Author(s):  
Arnaldo Walter ◽  
Joaquim Seabra ◽  
Jansle Rocha ◽  
Marjorie Guarenghi ◽  
Nathália Vieira ◽  
...  
Keyword(s):  
Necessary Conditions ◽  
Ghg Emissions ◽  
Economic Assessment ◽  
Sustainable Production ◽  
Civil Aviation ◽  
Spatially Explicit ◽  
Potential Production ◽  
Carbon Offsetting ◽  
Detailed Assessment ◽  
Land Economic

International civil aviation strives to significantly reduce its greenhouse gas (GHG) emissions, and the use of Sustainable Aviation Fuels (SAF) is an alternative for such purpose. However, for an alternative fuel to be considered SAF, some conditions must be met, and production must be certified for sustainability. This paper presents an assessment of the necessary conditions for the sustainable production of these biofuels in Brazil. It is based on a geospatial publicly available database (SAFmaps) that was built with the aim of providing information to stakeholders who would be interested in the production of SAF. The geographic scope corresponds to an area that is about half of the country. The case studies reported in this paper are related to four crop-based feedstocks (eucalyptus, soybean, sugarcane, and corn), which could be used for SAF production, according to three certified routes (FT, HEFA, and ATJ) (Fischer–Tropsch, Hydroprocessed Esters and Fatty Acids and Alcohol to Jet); in total, six potential production sites were assessed. For each crop, the detailed assessment is based on estimates of suitability for biomass production, yields, and costs. The assumptions made allowed us to explicitly analyse the risk of deforestation (production could only occur with displacement of pastures) and the necessary preservation of sensitive biomes and of legally protected areas, in addition to observing the restrictive conditions imposed by CORSIA (Carbon Offsetting and Reduction Scheme for International Aviation). To reduce GHG emissions, transporting biomass over long distances was assumed to be only by rail or pipeline. In addition, we address alternatives to minimise the risks associated with induced land-use change (iLUC) and to reduce impacts on the landscape. The results show that the production of SAF through the ATJ route, using ethanol produced from sugarcane and corn, requires less land. Economic assessment was outside the scope of this paper.

Effects of strategic tillage on short-term erosion, nutrient loss in runoff and greenhouse gas emissions

Soil Research ◽  
2017 ◽  
Vol 55 (3) ◽  
pp. 201 ◽  
Author(s):  
A. R. Melland ◽  
D. L. Antille ◽  
Y. P. Dang
Keyword(s):  
Nitrous Oxide ◽  
Greenhouse Gas ◽  
Heavy Rainfall ◽  
Ghg Emissions ◽  
Nutrient Loss ◽  
Nitrous Oxide Emissions ◽  
Nutrient Losses ◽  
Short Term ◽  
Trade Offs ◽  
Carbon Dioxide Co2

Occasional strategic tillage (ST) of long-term no-tillage (NT) soil to help control weeds may increase the risk of water, erosion and nutrient losses in runoff and of greenhouse gas (GHG) emissions compared with NT soil. The present study examined the short-term effect of ST on runoff and GHG emissions in NT soils under controlled-traffic farming regimes. A rainfall simulator was used to generate runoff from heavy rainfall (70mmh–1) on small plots of NT and ST on a Vertosol, Dermosol and Sodosol. Nitrous oxide (N2O), carbon dioxide (CO2) and methane (CH4) fluxes from the Vertosol and Sodosol were measured before and after the rain using passive chambers. On the Sodosol and Dermosol there was 30% and 70% more runoff, respectively, from ST plots than from NT plots, however, volumes were similar between tillage treatments on the Vertosol. Erosion was highest after ST on the Sodosol (8.3tha–1 suspended sediment) and there were no treatment differences on the other soils. Total nitrogen (N) loads in runoff followed a similar pattern, with 10.2kgha–1 in runoff from the ST treatment on the Sodosol. Total phosphorus loads were higher after ST than NT on both the Sodosol (3.1 and 0.9kgha–1, respectively) and the Dermosol (1.0 and 0.3kgha–1, respectively). Dissolved nutrient forms comprised less than 13% of total losses. Nitrous oxide emissions were low from both NT and ST in these low-input systems. However, ST decreased CH4 absorption from both soils and almost doubled CO2 emissions from the Sodosol. Strategic tillage may increase the susceptibility of Sodosols and Dermosols to water, sediment and nutrient losses in runoff after heavy rainfall. The trade-offs between weed control, erosion and GHG emissions should be considered as part of any tillage strategy.

scholarly journals Trade-offs between high yields and greenhouse gas emissions in irrigation wheat cropland in China

2014 ◽  
Vol 11 (8) ◽  
pp. 2287-2294 ◽  
Author(s):  
Z. L. Cui ◽  
L. Wu ◽  
Y. L. Ye ◽  
W. Q. Ma ◽  
X. P. Chen ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Greenhouse Gas ◽  
Ghg Emissions ◽  
Triticum Aestivum L ◽  
Ghg Emission ◽  
Trade Off ◽  
Trade Offs ◽  
High Yields ◽  
Scientific Attention

Abstract. Although the concept of producing higher yields with reduced greenhouse gas (GHG) emissions is a goal that attracts increasing public and scientific attention, the trade-off between high yields and GHG emissions in intensive agricultural production is not well understood. Here, we hypothesize that there exists a mechanistic relationship between wheat grain yield and GHG emission, and that could be transformed into better agronomic management. A total 33 sites of on-farm experiments were investigated to evaluate the relationship between grain yield and GHG emissions using two systems (conventional practice, CP; high-yielding systems, HY) of intensive winter wheat (Triticum aestivum L.) in China. Furthermore, we discussed the potential to produce higher yields with lower GHG emissions based on a survey of 2938 farmers. Compared to the CP system, grain yield was 39% (2352 kg ha−1) higher in the HY system, while GHG emissions increased by only 10%, and GHG emission intensity was reduced by 21%. The current intensive winter wheat system with farmers' practice had a median yield and maximum GHG emission rate of 6050 kg ha−1 and 4783 kg CO2 eq ha−1, respectively; however, this system can be transformed to maintain yields while reducing GHG emissions by 26% (6077 kg ha−1, and 3555 kg CO2 eq ha−1). Further, the HY system was found to increase grain yield by 39% with a simultaneous reduction in GHG emissions by 18% (8429 kg ha−1, and 3905 kg CO2 eq ha−1, respectively). In the future, we suggest moving the trade-off relationships and calculations from grain yield and GHG emissions to new measures of productivity and environmental protection using innovative management technologies.

Temporary Traffic Control Strategy Optimization for Urban Freeways

2018 ◽  
Vol 2672 (16) ◽  
pp. 68-78 ◽  
Author(s):  
Laura E. Ghosh ◽  
Ahmed Abdelmohsen ◽  
Khaled A. El-Rayes ◽  
Yanfeng Ouyang
Keyword(s):  
Energy Consumption ◽  
Control Strategy ◽  
Traffic Control ◽  
Travel Demand ◽  
Construction Cost ◽  
Start Time ◽  
Trade Offs ◽  
Decision Variables ◽  
Traffic Delay ◽  
Lateral Clearance

Temporary traffic control (TTC) strategies have been widely adopted to maintain traffic flow while ensuring TTC costs remain a reasonable portion of construction budgets. As travel demand approaches the capacity of an existing facility, implementation of an appropriate TTC strategy is increasingly important not only because lane closures on these facilities exacerbate existing delay, but also because speeds associated with congestion contribute disproportionately and non-linearly to roadway emissions produced throughout the lifetime of the roadway. To enable stakeholders to make informed and transparent decisions on selecting a TTC strategy so as to balance the trade-offs among construction cost, traffic delay, and energy consumption, this paper discusses the development of an integrated model that identifies the Pareto-optimal front when construction start time, construction duration, lateral clearance, and width of shoulder borrowed as a through lane are considered as decision variables. A test implementation of the model suggests that when construction budgets are low, strategies for decreasing traffic delay differ significantly from those for decreasing energy consumption; however, as construction budgets increase, the objectives on traffic delay and energy consumption align much better.

scholarly journals Strategies to Improve the Energy Performance of Buildings: A Review of Their Life Cycle Impact

Buildings ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 105 ◽  
Author(s):  
Nadia MIRABELLA ◽  
Martin RÖCK ◽  
Marcella Ruschi Mendes SAADE ◽  
Carolin SPIRINCKX ◽  
Marc BOSMANS ◽  
...  
Keyword(s):  
Life Cycle ◽  
Case Studies ◽  
Environmental Impacts ◽  
Energy Use ◽  
Ghg Emissions ◽  
Energy Performance ◽  
Environmental Benefits ◽  
Embodied Energy ◽  
Trade Offs ◽  
Operational Energy

Globally, the building sector is responsible for more than 40% of energy use and it contributes approximately 30% of the global Greenhouse Gas (GHG) emissions. This high contribution stimulates research and policies to reduce the operational energy use and related GHG emissions of buildings. However, the environmental impacts of buildings can extend wide beyond the operational phase, and the portion of impacts related to the embodied energy of the building becomes relatively more important in low energy buildings. Therefore, the goal of the research is gaining insights into the environmental impacts of various building strategies for energy efficiency requirements compared to the life cycle environmental impacts of the whole building. The goal is to detect and investigate existing trade-offs in current approaches and solutions proposed by the research community. A literature review is driven by six fundamental and specific research questions (RQs), and performed based on two main tasks: (i) selection of literature studies, and (ii) critical analysis of the selected studies in line with the RQs. A final sample of 59 papers and 178 case studies has been collected, and key criteria are systematically analysed in a matrix. The study reveals that the high heterogeneity of the case studies makes it difficult to compare these in a straightforward way, but it allows to provide an overview of current methodological challenges and research gaps. Furthermore, the most complete studies provide valuable insights in the environmental benefits of the identified energy performance strategies over the building life cycle, but also shows the risk of burden shifting if only operational energy use is focused on, or when a limited number of environmental impact categories are assessed.

scholarly journals Stochastic Modelling to Analyze the Impact of Electric Vehicle Penetration in Thailand

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5037
Author(s):  
Narongkorn Uthathip ◽  
Pornrapeepat Bhasaputra ◽  
Woraratana Pattaraprakorn
Keyword(s):  
Electric Vehicle ◽  
Distribution Systems ◽  
Fossil Fuels ◽  
Ghg Emissions ◽  
Stochastic Modelling ◽  
Stochastic Approach ◽  
Trade Offs ◽  
The Impact ◽  
Ev Charging ◽  
Charging Strategy

Electric Vehicle (EV) technology is one of the most promising solutions to reduce dependence on fossil fuels and greenhouse gas (GHG) emissions in the transportation sector. However, a large increase of EVs raises concerns about negative impacts on electricity generation, transmission, and distribution systems. This study analyzes the benefits and trade-offs for EV penetration in Thai road transport based on EV penetration scenarios from 2019 to 2036. Two charging strategies are considered to assess the impact of EV charging: free charging and off-peak charging. Uncertainty variables are considered by a stochastic approach based on Monte-Carlo simulation (MCS). The simulation results shown that the adoption of EVs can reduce both energy consumption and GHG emissions. The results also indicate that the increased load due to EV charging demand in all scenarios is still within the buffer level, compared to the installed generation capacity in the Power Development Plan 2018 revision 1 (PDP2018r1), and the off-peak charging strategy is more beneficial than the free-charging strategy. However, the increased load demand caused by all EV charging strategies has a direct impact on the power generating schedule, and also decreases the system reliability level.

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