Aspect Ratio Wing Research Articles

Detachment of leading-edge vortex enhances wake capture force production

During stroke reversals, insect wings interact with their own wake flow from the preceding half-stroke, resulting in an unsteady aerodynamic mechanism known as ‘wing–wake interaction’ or ‘wake capture’. To better elucidate this mechanism, we numerically solved the incompressible Navier–Stokes equations at Reynolds numbers $10^2$ and $10^3$ . Simulations were conducted for wing planforms defined using the beta function distribution with varying aspect ratios ( $AR=2\unicode{x2013}6$ ) and radial centroid locations ( $\hat {r}_1=0.4\unicode{x2013}0.6$ ), whilst employing representative normal hovering kinematics. The wake development from the considered flapping wing planforms was investigated, and the wake capture contribution to aerodynamic force production was quantified by comparing the force generation between the fifth and first stroke cycles at multiple sections along the wingspan. Our results revealed that on the inboard wing region experiencing an attached leading-edge vortex (LEV) structure, wing–wake interaction is dominated by an unsteady downwash effect, resulting in a reduction in local force production. However, in regions closer to the wingtip experiencing detachment of the LEV, wing–wake interaction is dominated by an unsteady upwash effect, leading to an increase in local force production. Consequently, the global wake capture force production is controlled by the extent of LEV detachment, which primarily increases with the increase of wing aspect ratio. This suggests that for normal hovering flapping wings, the typical loss in translational force production due to wingtip stall is partially mitigated by wake capture effects.

On the role of wake-capture and resonance in spanwise-flexible flapping wings in tandem

Numerical simulations of the flow around spanwise-flexible flapping wings in tandem are reported, focusing on a thrust-generating configuration. Wings of aspect ratio 2 and 4 in forward flight undergo heaving and pitching motion following optimal 2D kinematics. The Reynolds number of the simulations is Re=1000. The effect of flexibility is explored by varying the effective stiffness of the wings, while the effective inertia is kept constant. The aerodynamic performance of the tandem system results from a combination of unsteady aerodynamics mechanisms, fluid–structure resonance, vortex–wing interactions (denoted wake capture in this study) and aerodynamic tailoring. It is found that the aerodynamic performance and structural behavior of forewings are dominated by a fluid–structural resonance. The maximum mean thrust for the forewings is obtained when the driving frequency approaches the first natural frequency of the structure, ωn,f/ω≈1, similarly to what is observed in isolated wings undergoing the same kinematics. On the other hand, hindwings show optimal performance in a broad region near ωn,f/ω≈2, and their aerodynamic performance seems to be dominated by wake–capture and aerodynamic–tailoring effects. The aerodynamic performance of the hindwings is dependent on the flexibility of the forewing, which impacts the intensity of the vortices shed into the wake and the resulting effective angle of attack (i.e., wake capture). The timing between the effective angle of attack and the pitching motion of the hindwing controls the generation of thrust (or drag) of each spanwise section of the hindwing (i.e., aerodynamic tayloring). A proof of concept study on the aerodynamic performance of systems made of wings with different flexibility suggests that they could outperform tandem systems with equally flexible wings. Thus, the optimal mixed–flexibility tandem system is composed by a resonant forewing, which maximizes the thrust generation of the forewing and the intensity of the vortices shed into the wake, and a hindwing whose flexibility must be tuned to maximize wake capture effects.

Research of correlation between aspect ratio and descent rate-Based on paper-plane using experiment

The aspect ratio is important to airplane performance because it affects the aircrafts performance by changing the geometry of the aerofoil, which affects the lift the aerofoil can generate. An experiment of testing 5 planes with different wing aspect ratio has performed in order to figure out the relationship between aspect ratio and descent rate. The experiment is based on small scale model. Before the experiment, analysis based on physics computation show some advantage of small scale model. The wing of the model airplane is made of paper, and the fuselage is made from paperboard. The plane is released at a certain height by a rubber band which allow the plane to glide. Finally, the experiment shows that although the increase in aspect ratio can improve the performance of the plane, the performance will get worst as aspect ratio increases after a critical aspect ratio. Computation of the average descent rate and comparison in gliding distance of different wing aspect ratio obtained by the experiments show the optimal value of AR is 5.1.

Research on Aerodynamic Characteristics of Gliders with Different Wing Shapes

In this research, the effects of different wing shapes on the lift-to-drag ratio and aerodynamic characteristics of gliders were analyzed. Traditional research has many limitations, such as experimental conditions - air flow speed and airflow stability, which may affect the stability of research results. Therefore, in this research, repeated experiments were used to eliminate chance, and numerical simulation was combined with computer simulation of the lift-to-drag ratio of gliders under different aspect ratios to verify the experimental results. The results show that with the increase in aspect ratio, the lift-drag ratio of the glider increases. A glider that has a greater wing aspect ratio can generate more lift force at the same given speed, reducing the descent speed and extending the glide distance, showing better aerodynamic characteristics. By studying the aspect ratio, the optimal wing shape and size for a specific aircraft can be determined to improve the lift and drag characteristics of the glider. This research has important guiding significance for glider design, which can improve the performance and efficiency of gliders.

A Study on the Surrogate-Based Optimization of Flexible Wings Considering a Flutter Constraint

Accounting for aeroelastic phenomena, such as flutter, in the conceptual design phase is becoming more important as the trend toward increasing the wing aspect ratio forges ahead. However, this task is computationally expensive, especially when utilizing high-fidelity simulations and numerical optimization. Thus, the development of efficient computational strategies is necessary. With this goal in mind, this work proposes a surrogate-based optimization (SBO) methodology for wing design using a predefined machine learning model. For this purpose, a custom-made Python framework was built based on different open-source codes. The test subject was the classical Goland wing, parameterized to allow for SBO. The process consists of employing a Latin Hypercube Sampling plan and subsequently simulating the resulting wing on SHARPy to generate a dataset. A regression-based machine learning model is then used to build surrogate models for lift and drag coefficients, structural mass, and flutter speed. Finally, after validating the surrogate model, a multi-objective optimization problem aiming to maximize the lift-to-drag ratio and minimize the structural mass is solved through NSGA-II, considering a flutter constraint. This SBO methodology was successfully tested, reaching reductions of three orders of magnitude in the optimization computational time.

Aerodynamic Performance Enhancement of Low Aspect Ratio Military Drone Aircraft Wing through Employing Leading Edge Tubercles

Present study aim to improve the aerodynamic performance of low Aspect Ratio (AR) military drone aircraft wing, through employing leading edge tubercle. For that purpose two wing model were design one with smooth leading edge and second with tubercle leading edge. The wing models were developed by using NACA0012 airfoil profile, whereas tubercles of amplitude 5% of chord (c) and wavelength of 11% of c is employed. The numerical simulation as performed at chord based Reynolds number of 140000 in pre-stall and post stall regime. The computational fluid dynamic simulation is performed at different angle of attack ranging from 0 degree to 25 degree with the interval of 5 degree. Computational Fluid Dynamics (CFD) results reveal that tubercle at the leading edge of the low AR wing has favorable effect on the wing performance. Aerodynamic performance of both smooth leading edge and tubercle leading edge wing is similar up to 15o angle of attack, whereas at 20 degree and 25 degree significant improvement in Lift-to-Drag L/D ratio is observed. It is estimated that at maximum increment of 53% in lift coefficient ii achieved at 25 degree angle of attack for as compared to smooth LE wing model. Moreover, maximum 20.5% decrease in drag coefficient is estimated in case of tubercle leading edge as compared to baseline model at 20 degree angle of attack. The critical observation of field around the tubercle leading edge wing is found that tubercles restrict flow separation through generation of low strength vortices; these vortices enhance momentum exchange within the boundary layer.

Determination of the features of integrated design of civil long-range aircraft with transonic truss-braced wing at the preliminary design stage

The object of research is a civil mainline aircraft with a transonic truss-braced wing. The problem of designing an aircraft of this scheme at the preliminary design stage is being solved in the work. The results of the work include the concept of designing aircraft with a transonic truss-braced wing, the main advantages of such a scheme, the process of determining the geometric parameters of the truss-braced, features of the preliminary design of an aircraft with an extremely high aspect ratio truss-braced wing, possible approaches to the arrangement of units and their mutual arrangement. The results are explained by the difference in the design model (the cantilever beam is replaced by a beam on two supports) in mass analysis and the increased wing aspect ratio in aerodynamic calculation. The final data are based on a statistical study to determine the basic geometric parameters of assemblies of modern mainline passenger aircraft, synthesis of parameters of analog aircraft. For example, an aircraft capable of carrying 250 passengers over a distance of 13.000 km is considered. In the design process, values of aspect ratio, taper ratio, wing area, vertical tail and horizontal tail area ratio, and fuselage dimensions are accepted. Drawings of the general appearance of the aircraft have been developed and, based on it, a master geometry of the theoretical contour has been constructed. Graphs of first-order polar and maximum lift-to-drag ratio have been plotted, the reduction of aerodynamic drag in percentage terms has been determined, and the increase in aerodynamic lift-to-drag ratio in percentage terms for an aircraft with an extremely high aspect ratio truss-braced wing compared to similar characteristics of an aircraft with a conventional non-braced wing has been calculated. The approximate mass savings when using a truss-braced wing on the aircraft are determined in percentage terms. The expediency of using wings of greater aspect ratio, than modern aircraft currently have, has been justified. The expediency of using a brace for the aircraft with an extremely high aspect ratio wing has been justified. The obtained results can be used in practice in the process of developing the preliminary design of an aircraft with a truss-braced wing or in the modifications of existing aircraft to increase their fuel efficiency or increase the durability of wing elements due to reduced loads acting on them.

On the secondary stall of a wing in tandem configuration

Abstract The aerodynamic response of a NACA0012 wing section was investigated at a Reynolds number of 100,000 in an open return wind tunnel in the presence of a second wing in tandem. The angle-of-attack of the front wing ranged from −5° to 90° while the rear wing remained at zero incidence. The presence of the downstream wing significantly altered the post-stall behaviour of the upstream wing in the form of a secondary stall characterised by a sudden drop in lift and drag for a specific combination of angle-of-attack and the spacing between the wings. The secondary stall was found to be insensitive to the Reynolds number and the aspect ratio of the downstream wing and did not affect the lift-to-drag ratio. Flow visualisation in the water tunnel indicated that the downstream wing effectively suppressed vortex shedding and lift fluctuations of the upstream wing.

Is wing morphology across birds associated with life history and sociality?

Wings in birds vary tremendously in size and shape across species. Ecological needs are thought to shape variation across species in wing morphology over evolutionary times. For instance, demands for energetic efficiency in species that fly long distances have produced long and narrow wings with a high aspect ratio. Demand for maneuverability in cluttered habitats or to escape predators more easily have favored wings with large areas relative to body size producing a low wing loading. The association between ecological needs and wing morphology is complex, however, and could involve other ecological variables. Here, I draw attention to two ecological factors that have received little attention, namely, life history and sociality. Species at the slow end of the life history continuum emphasize adult survival over reproduction and are considered risk averse. I predicted that such species would benefit from low wing loading and low aspect ratio to increase maneuverability and the ability to escape predators. More solitary species cannot rely on others in their groups to decrease predation risk. I predicted that such species should also benefit from low wing loading and low aspect ratio. Using data from the literature on wing loading and aspect ratio in a large number of species, I examined these predictions in a phylogenetic framework including several potentially confounding ecological variables that have been previously linked to wing morphology such as habitat, lifestyle, and migration. As predicted, more solitary species tended to have low wing loading and low aspect ratio. Low wing loading was also more common in species at the slow end of the life history continuum, but aspect ratio was higher than predicted. Overall, the results support the idea that life history and sociality can predict variation across species in wing morphology and highlight the effect of predation risk on the evolution of wing morphology in birds.

Boundary Element Method Analysis of 3D Effects and Free-Surface Proximity on Hydrofoil Lift and Drag Coefficients in Varied Operating Conditions

_ The use of hydrofoils to enhance ship performance raises the scientific issue of free-surface proximity, which is important to consider during the design stage, to feed velocity prediction programs, for instance. Typically, the flow over a shallowly submerged hydrofoil is characterized by the Froude number, the submergence depth-to-chord ratio, the angle of attack, and geometric parameters of the lifting surface. Among these parameters, the present paper investigates the influence of the wing aspect ratio on the lift and drag coefficients of hydrofoils operating near a free surface. For this purpose, rectangular wings with an H105 profile at 2° angle of attack and aspect ratios ranging from 4 to 20 are systematically analyzed using a 3D boundary element method. The free surface is modeled using a linearized Neumann-Kelvin boundary condition. Chord-based Froude numbers of 0.5, 1.1, and 6.3 are studied. The submersion depth is swept between 0.1 and 30 times the foil chord length. The evolution of the normalized lift and drag coefficients with respect to the foil submersion and the aspect ratio is discussed in detail. Flow velocity is shown to play a significant role in the evolution of the lift and drag coefficients with submersion depth, close to the free surface, for all the aspect ratios. Its influence gets reduced by moving away from the free surface. The critical submersion depth, where the free-surface effects cease, is found to increase with higher flow velocity and aspect ratio. Furthermore, both positive and negative correlations between the force coefficients and the aspect ratio are identified, depending on the operating conditions. It is found that when the proximity to the free surface either enhances or impairs a force coefficient relative to its value in unbounded flow, increasing the aspect ratio amplifies this effect. Overall, this study confirms the effectiveness of steady boundary element methods for simulating the flow around hydrofoil wings in the vicinity of a free surface and contributes to further understanding the influence of geometric parameters on hydrofoil performance. Keywords hydrofoil; free surface; aspect ratio; potential flow; boundary element method (BEM)

Urbanisation reduced body size but potentially improved flight performance in bees and wasps

Urbanisation is a main driver of land-use change, leading to rising in temperatures and fragmentation and reduction of green areas. Bees and wasps, which are important insect groups due to the ecosystem services they provide, may respond to this disturbance via changes in morphological traits which are functionally relevant. To date, studies focusing on this aspect only investigated few social bee species, and often gave contrasting results even at intra-generic level. Here, we studied how body size, wing loading, wing aspect ratio and wing fluctuating asymmetry vary in a social ground-nesting bee (Halictus scabiosae), a solitary hole-nesting bee (Osmia cornuta) and a social paper wasp (Polistes dominula) along an urbanisation gradient within Milan (Italy). By assessing the effects of temperature, green areas fragmentation and vegetation productivity on the above-listed functional traits, we found the three species to variably respond to increasing urbanisation, albeit the driving environmental parameters differed among species. More specifically, smaller individuals were sampled in warmer (for bees) and in less productive (for wasps) areas along the urbanisation gradient. Furthermore, greater wing aspect ratio values were recorded at warmer locations for H. scabiosae, lower wing loading was recorded at more fragmented sites for O. cornuta, and greater wing loading was recorded at locations with greater productivity for P. dominula. H. scabiosae and P. dominula showed greater wing fluctuating asymmetry at more fragmented sites. Although distinct species seemed sensitive to different driving factors, our results point toward a consistent response: smaller body but potentially improved flight performance in more urbanised environments.

Aerostructural Optimization and Comparative Study of Twin-Fuselage and Strut-Braced-Wing Aircraft Configurations

The ultrahigh-aspect-ratio wing (UHARW) concept is a promising configuration to achieve future sustainable aviation goals. Twin-fuselage (TF) and strut-braced-wing (SBW) configurations are characterized by smaller structural bending moments and shear forces in the wing and are promising concepts for realizing UHARW designs. This paper addresses the aerostructural optimization problem of TF and SBW configurations with UHARW by using a coupled adjoint aerostructural optimization tool, which is composed of a geometrically nonlinear structural solver and a quasi-three-dimensional natural laminar flow (NLF) aerodynamic solver. The optimization results show significant improvements in fuel efficiency and performance for the TF and SBW aircraft, with fuel mass reductions of 13 and 10%, respectively, compared to the corresponding baseline aircraft designed in the conceptual design phase. In comparison to the original reference aircraft A320neo, the optimized TF and SBW have 48 and 31% lower fuel weights, respectively. The NLF range of both upper and lower wing surfaces is expanded during optimization. The optimized SBW configuration has a wing aspect ratio of 26.01, while the optimized TF has a wing aspect ratio of 20.74, indicating that the SBW concept is more conducive to realizing UHARW design compared with the TF configuration studied in this work. The optimized TF aircraft has a lighter fuel weight and gross weight compared to the optimized SBW aircraft, which is because the TF aircraft has a lighter operational empty weight, including a lighter fuselage structural weight, landing gear weight, etc., whereas the top-level aircraft requirements are the same for both aircraft, including range, payload, and cruise Mach.

Refining the airborne wind energy system power equations with a vortex wake model

Abstract. The power equations of crosswind Ground-Gen and Fly-Gen airborne wind energy systems (AWESs) flying in circular trajectories are refined to include the contribution from the aerodynamic wake, modeled with vortex methods. This reveals the effect of changing the turning radius, the wing geometry and the aerodynamic coefficients on aerodynamic performances and power production. A novel power coefficient is defined by normalizing the aerodynamic power with the wind power passing through a disk with a radius equal to the AWES wingspan, enabling the comparison of different designs for a given wingspan. The aspect ratio which maximizes this power coefficient is finite, and its analytical expression for an infinite turning radius is derived. By considering the optimal wing aspect ratio, the maximum power coefficient is found, and its analytical expression for an infinite turning radius is derived. Ground-Gen and Fly-Gen AWESs, with the same idealized characteristics, are compared in terms of power production, and later three AWESs from the literature are analyzed. With this modeling framework, Ground-Gen systems are found to have a lower power potential than Fly-Gen AWESs with the same geometry because the reel-out velocity makes Ground-Gen AWESs fly closer to their own wake.

The relationship between morphology and flight in Drosophila: a study of two pairs of sibling species from a natural population.

Insect flight is a complex trait involved in different behaviors, from the search for sexual partners, food, or breeding sites. Many studies have postulated the adaptive advantages of certain morphological traits in relation to increased flight capacity, such as low values of wing loading or high values of wing:thorax ratio and wing-aspect ratio. However, few studies have evaluated the relationship between variables related to flight and morphological traits in Drosophila. This work aimed to study morphological traits in males and females of two pairs of sibling species: Drosophila buzzatii Patterson and Wheeler-Drosophila koeferae Fontdevila and Wasserman, and Drosophila melanogaster Meigen-Drosophila simulans Sturtevant, and to analyze its relationship with flight. We detected the highest proportion of flight time in D. koepferae and D. simulans compared to D. buzzatii and D. melanogaster, respectively. Our results also revealed sexual dimorphism, with males exhibiting a higher proportion of flight time than females. Surprisingly, we did not find a general pattern to explain the relationship between morphology and the proportion of flight time because associations varied depending upon the analyses (considering all groups together or each sex-species combination separately). Moreover, these associations explained a low percentage of variation, suggesting that other nonmorphological components related to flight, such as physiological variables, should be taken into account. This work allowed us to show the variability and complexity of an aspect of flight, suggesting that the adaptive role of the morphological traits studied might have been overestimated.

Conceputal Sizing and Multicriteria Optimization of UAV for Snow Studies

This paper describes a methodology for conceptual design and sizing of a UAV to be used for snow cover evaluation and other scientific studies in lower Himalayas. The problem is posed in a multi-criteria optimization framework with wing span (representing size) and stall speed (representing performance) as the two conflicting objective functions. Eleven design variables are considered, which relate to the geometry and mass. In addition, an engine selection parameter is also used. Inequality and equality constraints are imposed on the design. The design is optimized with genetic algorithm independently for takeoff mass and stall speed. Multi-objective optimization is carried out for the stall speed and wing span as objective functions. For most cases, the optimum configuration has the lowest wing aspect ratio, highest wing t/c ratio, smallest aircraft length and highest flap area fraction. Low aspect ratio and high t/c for the wing result in lower wing weight.

Evolutionary divergence of body size and wing and leg structure in relation to foraging mode in Darwin’s Galapagos finches

Abstract The wings, legs, and tail in Darwin’s finches show many clear adaptations to different types of locomotion used during foraging. We use size scaling to analyse how various characters vary with body mass to clarify dimensional relationships. The selective advantage of a character is judged in terms of energy savings. The wing aspect ratio (4.6–4.9) is very low, so the energy costs for flight are high. Low body mass, low wing loading, and short arm wings in the warbler finch, small tree finch, and small ground finch promote agility and manoeuvrability among vegetation, along with short wings in the warbler finch. Evolution towards a shorter arm wing seems to be favoured in the smaller finch species. Long legs, long toes, and long curved claws are adaptations for climbing/clinging locomotion without tail support (woodpecker finch, small and large tree finches, cactus finch but having short legs). Selection for longer legs seems to act towards a lengthening of the tarsometatarsus. The climbing technique in the woodpecker finch is described. We discuss how the diversification in the beaks relates to the locomotion organs.

Drivers affecting habitat use in Afrotropical hipposiderid and pteropodid bats

AbstractAssessing how bats respond to habitat attributes requires an integrative approach to reliably predict direct community‐level effects. We focused on hipposiderid and pteropodid bats because of their diverse resource use patterns, body size ranges, and dispersal abilities. We combined an array of bat species‐level characteristics with key forest stand characteristics that may covary with habitat use. Twelve stations were sampled in the Lomami and Yangambi landscapes, Democratic Republic of the Congo. We investigated whether species‐level flight ability of bats and forest stand characteristics can affect bat commuting flights and community‐level estimates of both species detection and habitat occupancy. We captured bats for 108 trap‐nights. Three sampling events (early evening, middle of the night, and early morning) were replicated for each survey night. Hipposiderids showed an early evening flight peak, while flight activity of pteropodids was constant throughout the night, but increased around the middle of the night. Species capture probability decreased with higher wing loading in hipposiderids and was negatively correlated with higher wing aspect ratio in pteropodids. Forest occupancy of hipposiderids increased along the gradient towards waterways, while pteropodid occurrence was not directly linked to measured forest stand variables. This suggests a consequence of habitat patterns at larger spatial scales, which would need clarifying through additional data collection. We discuss these findings in terms of resource‐use strategies of clutter‐tolerant and clutter‐intolerant species. We argue that the occurrence of specific bat species and their habitat use patterns can serve as surrogate measures of ecosystem health.

Examination and Prediction of the Lift Components of Low Aspect Ratio Rectangular Flat Plate Wings

An investigation of the lift components present over low aspect ratio rectangular wings is presented. Wing aspect ratios ranging from 0.5 to 3 are examined using published experimental results and analytic analysis methods. The methods are based on the fundamental decomposition of Polhamus; that is, lift is attributed to a potential flow lift component coupled with a vortical lift component stemming from the leading and side edges of the flat plate wing. The analysis suggests a low sensitivity to Reynolds numbers spanning three orders of magnitude and brings into doubt the realization of a leading edge vortex lift component for wings with unswept leading edges under steady state conditions. The analytic prediction method of Purvis is shown to provide close accord with all experimental data sets when lift contributions caused by a leading edge vortex are excluded.

Decoupling wing-shape effects of wing-swept angle and aspect ratio on a forward-flying butterfly.

The effect of wing shape on a forward-flying butterfly via decoupled factors of the wing-swept angle and the aspect ratio (AR) was investigated numerically. The wing-shape effect is a major concern in the design of a microaerial vehicle (MAV). In nature, the wing of a butterfly consists of partially overlapping forewing and hindwing; when the forewing sweeps forward or backward relative to the hindwing, the wing-swept angle and the AR of the entire wing simultaneously change. The effects of the wing-swept angle and AR on aerodynamics are coupled. To decouple their effects, we established wing-shape models with varied combinations of the wing-swept angle and AR based on the experimental measurement of two butterfly species (Papilio polytes and Kallima inachus) and developed a numerical simulation for analysis. In each model, the forewing and hindwing overlapped partially, constructing a single wing. Across the models, the wing-swept angle and AR of these single wings varied sequentially. The results show that, through our models, the effects of the wing-swept angle and AR were decoupled; both have distinct flow mechanisms and aerodynamic force trends and are consistent in the two butterfly species. For a fixed AR, a backward-swept wing increases lift and drag because of the enhanced attachment of the leading-edge vortex with increased strength of the wingtip vortex and the spanwise flow. For a fixed wing-swept angle, a small AR wing increases lift and decreases drag because of the large region of low pressure downstream and the wake-capture effect. Coupling these effects, the largest lift-to-drag ratio occurs for a forward-swept wing with the smallest AR. These results indicate that, in a flapping forward flight, sweeping a forewing forward relative to a hindwing is suitable for cruising. The flow mechanisms and decoupled and coupled effects of the wing-swept angle and the AR presented in this paper provide insight into the flight of a butterfly and the design of a MAV.

Deriving a year 2040 reference aircraft from a modern turboprop, implemented and calibrated in SUAVE

The FUTPRINT50 project is focused on designing and preparing ground for a hybrid-electric regional aircraft with a capacity of 50 passengers. The aircraft is designed for entry-into-service between 2035 and 2040. To evaluate and refine the design concepts, the project will use two different reference aircraft: one that is state-of-the-art, and another that is extrapolated to represent what a year 2040 model might look like. The ATR 42-500, a 50-seat aircraft with a design range of 840 nautical miles, will serve as the year 2000 reference aircraft. As part of the project, the open-source aircraft design tool SUAVE is adapted for use with hybrid-electric aircraft. The ATR 42-500 was reverse-engineered in the same SUAVE environment using official manufacturer data and other sources for reference and calibration. The environmental impact of the aircraft is assessed based on its emissions of CO2, NOX, and noise. The technology used in the ATR 42-500 will be outdated by 2040. To estimate the impact of the year 2035/2040 hybrid components, a year 2040 reference aircraft was implemented. This aircraft is based on the ATR 42-500 but will incorporate several further enhanced technologies, such as a higher wing aspect ratio, more efficient engines, and improved materials.