Aerodynamic Performance Of Wing Research Articles

A chemo-mechanical constitutive model for muscle activation in bat wing skins.

Birds, bats and insects have evolved unique wing structures to achieve a wide range of flight capabilities. Insects have relatively stiff and passive wings, birds have a complex and hierarchical feathered structure and bats have an articulated skeletal system integrated with a highly stretchable skin. The compliant skin of the wing distinguishes bats from all other flying animals and contributes to bats' remarkable, highly manoeuvrable flight performance and high energetic efficiency. The structural and functional complexity of the bat wing skin is one of the least understood although important elements of the bat flight anatomy. The wing skin has two unusual features: a discrete array of very soft elastin fibres and a discrete array of skeletal muscle fibres. The latter is intriguing because skeletal muscle is typically attached to bone, so the arrangement of intramembranous muscle in soft skin raises questions about its role in flight. In this paper, we develop a multi-scale chemo-mechanical constitutive model for bat wing skin. The chemo-mechanical model links cross-bridge cycling to a structure-based continuum model that describes the active viscoelastic behaviour of the soft anisotropic skin tissue. Continuum models at the tissue length-scale are valuable as they are easily implemented in commercial finite element codes to solve problems involving complex geometries, loading and boundary conditions. The constitutive model presented in this paper will be used in detailed finite element simulations to improve our understanding of the mechanics of bat flight in the context of wing kinematics and aerodynamic performance.

Experimental investigation of wing-propeller aerodynamic interaction in eVTOL configurations

The present study is aimed at the experimental investigation of the effects of wing-propeller aerodynamic interaction in a boom-mounted configuration typically used in eVTOL aircraft. The investigation was focused on the repercussions on wing and propeller performance coming from the variation of angle of attack, advance ratio and blades sense of rotation. Moreover, particular attention was devoted to the evaluation of the effect of the propeller's longitudinal offset. Results of a comprehensive wind tunnel campaign performed on a propeller-mounted wing scaled model confirmed the advantageous effects of an inboard-up rotating propeller on lift generation and drag reduction, while outlined the opposite sensitivity of wing and propeller performances when exposed to a non-zero angle of attack. Propeller's longitudinal offset instead led to slight alterations on wing and propeller aerodynamic performance, while a noteworthy sensitivity on the mounting setup was perceived by propeller aerodynamic performance. Moreover, PIV measurements allowed to evaluate quantitatively the effects of the investigated parameters on propeller slipstream behaviour and blade tip vortices pattern.

Passive flow-field control using dimples for improved aerodynamic flow over a wing

This study explores the efficacy of dimples in influencing the aerodynamic performance of a straight rectangular wing. Computational Fluid Dynamics based numerical simulations were performed to model turbulent flow and quantify the forces exerted on the wing. The k-ω Shear-Stress Transport turbulence model was chosen to solve the underlying equations. To ascertain reliability, the results of numerical simulations were compared with both experimental and simulation results of the previous studies. The impact of various dimple configurations, placed at 15%, 50% and 85% of the chord length, on the aerodynamic performance of the wing was investigated. The evaluation involved analyzing the drag coefficient (CD), lift coefficient (CL), lift-to-drag (L/D) ratio, streamlines and the flow field around wing in both chordwise and spanwise directions. The findings indicated that a wing with a dimpled surface could yield a reduced drag coefficient of up to 6.6% compared to the unmodified wing. This reduction is attributed to the dimples ability to sustain attached airflow and delay flow separation. The results demonstrated negligible deviation in the lift coefficient with the incorporation of dimples. The incorporation of dimples on the wing surface has been demonstrated to enhance the aerodynamic performance of lifting surfaces.

Turbulence model study for aerodynamic analysis of the leading edge tubercle wing for low Reynolds number flows

A turbulence model study was performed to analyze the flow around the Tubercle Leading Edge (TLE) wing. Five turbulence models were selected to evaluate aerodynamic force coefficients and flow mechanism by comparing with existing literature results. The selected models are realizable k-ε, k-ω Shear Stress Transport (SST), (γ−Reθ) SST model, Transition k-kl-ω model and Stress- ω Reynolds Stress Model (RSM). For that purpose, the TLE wing model was developed by using the NACA0021 airfoil profile. The wing model is designed with tubercle wavelength of 0.11c and amplitude of 0.03c. Numerical simulation was performed at chord-based Reynolds number of Rec = 120,000. The Computational Fluid Dynamic (CFD) simulation reveals that among the selected turbulence models, Stress- ω RSM estimated aerodynamic forces (i.e. lift and drag) coefficients closest to that of the experimental values followed by realizable k-ε, (γ−Reθ) SST model, k-ω SST model and k-kl-ω model. However, at a higher angle of attacks i.e. at 16° & 20° k-ω SST model predicted closest drag and lift coefficient to that of the experimental values. Additionally, the critical observation of pressure contour confirmed that at the lower angle of attack Stress- ω RSM predicted strong Leading Edge (LE) suction followed by realizable k-ε, (γ−Reθ)SST model, k-ω SST model and k-kl-ω model. Thus, the superiority of Stress- ω RSM in predicting the aerodynamic force coefficients is shown by the flow behavior. In addition to this pressure contours also confirmed that k-kl-ω model failed to predict tubercled wing aerodynamic performance. At higher angles of attacks k-ω SST model estimated aerodynamic force coefficients closest to that of the experimental values, thus k-ω SST model is used at 16° & 20° AoAs. The observed streamline behavior for different turbulence models showed that the Stress- ω RSM model and k-kl-ω model failed to model flow behavior at higher AoAs, whereas k-ω SST model is a better approach to model separated flows that experience strong flow recirculation zone.

Comprehensive effects of aerodynamic performance and dynamic strength of aircraft wings after bird strike in numerical simulation

ABSTRCT To enhance the bird strike resistance of fixed-wing aircraft wings, a combined computational approach integrating nonlinear solid mechanics and fluid dynamics was employed to analyze the bird strike characteristics of both traditional aluminum alloy skins and novel composite materials skins. Additionally, a standardized procedure was established to simulate aircraft structural damage more comprehensively, swiftly, and accurately during bird strikes, along with diagnostic analysis of flow field changes near the wing post-impact. This method not only quantifies wing strength damage but also establishes corresponding relationships between damage severity and aerodynamic performance degradation. The research findings indicate that the deformation of composite material skin wings is only a quarter of that of aluminum alloy skin wings. Composite material skins absorb less harmful energy compared to aluminum alloy skins, with consistently lower stiffness reduction rates at various bird strike velocities. Velocity distribution on deformed wings with composite material skins exhibits minimal deviation compared to normal wings, thereby preventing airflow separation. The research results provide more comprehensive guidance for the selection of materials for bird strike resistance of aircraft wings and the airworthiness evaluation after bird strikes. Highlights This paper establishes a standardized procedure that enables a more comprehensive, faster, and higher-precision simulation of structural damage to the aircraft during a bird strike on the wing and allows for the diagnostic analysis of the flow field changes near the wing after bird strike. By coupling nonlinear solid mechanics and fluid dynamics computational methods, the aerodynamic performance of the wings at different angles of attack post-deformation is investigated. This approach not only quantifies the strength damage to the wings but also establishes corresponding relationships between the degree of damage and the deterioration in aerodynamic performance. The research yields insights into the aerodynamic performance degradation patterns with varying angles of attack for both composite material skin and aluminum alloy skin deformed wings. These findings can serve as valuable references for pilots in emergency situations, aiding in their decision-making regarding aircraft control.

Real-time optimization of wing drag and lift performance using a movable leading edge

A real-time optimization strategy can provide any system with a considerable boost in performance on the fly, which in real-world applications can be translated to lower energy consumption or higher efficiency. This study investigates the particular case of using real-time optimization to improve wing aerodynamic performance with a dynamically activated deflectable leading edge. Its activation aims to minimize drag and maximize lift and is governed by real-time and gradient-based optimization. An extension to a classic method is suggested to enhance gradient estimation accuracy. Experimental data are obtained at a Reynolds number of 2.0×105 with the wing fixed at five positions. For each of these positions, optimal leading-edge deflections are found. The results indicate that deflecting the leading edge has a negligible impact on drag and lift before the stall onset. However, the reduction in the pitching moment cannot be ignored. When the wing is experiencing a proper stall, the movable leading edge yields remarkable enhancements, with the lift being approximately raised by 45% together with a substantial increase in the critical angle of attack. The findings highlight the potential of real-time optimization in experimental aerodynamic studies, reinvigorating its application in improving aircraft performance.

Gliding Analysis of Segmented Flapping Wing

A variety of aircraft morphing technologies have been investigated and represented by various researchers in the public domain. The morphing wing concepts involved the modification of aircraft wings during the in-flight course. Most of the technologies/concepts were based on biomimicry, where wing aerodynamic performance improved due to the change in wing shape. Here we describe a novel concept where in the flow parameters of airfoils arranged in configurations are investigated. The flow parameters are investigated using the numerical simulation tool ANSYS. A 2d flow simulation is performed using a Fluent solver to evaluate the flow configuration of the airfoils arranged in different configurations. The first configuration of airfoils is named a base, wherein the airfoils are arranged at zero angles of attack. The other two configurations are arranged by increasing the angular position of airfoils i.e., 15, 30, and 45 degrees. All these configurations are aerodynamically investigated at different sub-sonic speeds.

Scarab Beetle‐Inspired Embodied‐Energy Membranous‐Wing Robot with Flapping‐Collision Piezo‐Mechanoreception and Mobile Environmental Monitoring

AbstractThe mechanoreception system in bionic micro air vehicles, akin to insect sensory neurons, handles internal and external stimulus information. However, current onboard mechanoreception methods add weight and necessitate additional power. Employing the embodied energy design paradigm, a lightweight intelligent membranous wing is proposed, mimicking the scarab beetle's hindwing morphology and kinematics. This wing serves multiple functions, including aerodynamic load‐bearing, flight piezo‐mechanoreception, and power supply. The beetle's semi‐tubular costa structure is replicated, featuring a compliant leading edge for upstroke aerodynamic load resistance. Inspired by beetle hindwing veins and membranes, the bionic wing with three membranous fields: anal, medial, and apical, using heat lamination of multilayer materials is fabricated. The bionic wing's aerodynamic performance closely mirrors that of a real beetle hindwing, enabling various flight maneuvers and validating its real‐flight potential. As a piezo‐mechanoreception receptor for micro air vehicles, the bionic intelligent wing senses flapping frequency, wing deformations, and collisions through voltage signals from piezoelectric materials in the three membranous fields. Energy harvested from flapping‐wing motion powers onboard light intensity and ultraviolet sensors for mobile 3D environmental monitoring. This integration of aerodynamics, mechanoreception, and power supply via embodied flapping energy offers a novel approach for designing future intelligent flapping‐wing micro air vehicles.

Aerodynamic performance of aircraft wings with stationary vertical lift propellers

Improvements in battery and motor technology are facilitating innovative aircraft configurations capable of vertical take-off and landing. Of these configurations, lift+cruise is popular for its inherent redundancy and the option to tailor separate propulsion systems for each flight regime. During cruise, the vertical flight propellers of a lift+cruise design are inactive and often exposed. Increasing the projected area of a body is understood to increase the drag, but the aerodynamic performance of an edgewise, stationary propeller and its influence on neighboring bodies is less clear. This study aimed to quantify the impact of two, tandem, edgewise and stationary propellers on the aerodynamic performance of a wing using wind tunnel measurements. The stationary position of the front and rear propellers were varied in 30∘ increments between 0-150∘, at angles of attack between -4∘ and 10∘. Results at Re = 4.3×105 showed the propellers and supporting systems had negligible influence on the lift. However, a drag increase of up to 30% was recorded when propeller positions were aligned perpendicular to the wing chord instead of parallel. Variations in the stationary position of the propeller altered the lift to drag ratio by up to 36% in a typical cruise configuration.

Numerical Study of Flow Control on Simplified High-Lift Configurations

Enhancement in the aerodynamic performance of wings and airfoils is very notable when Active Flow Control (AFC) is applied to Short Take-off and Landing aircraft (STOL). The present numerical study shows the application of steady, pulsed and synthetic tangential jets applied to the plain flap shoulder of a modified NASA Trapezoidal Wing. Pulsed jets are modeled by sinusoidal and square waveforms while synthetic jets are modeled only by pure sine waveform. The freestream airflow conditions are Mach number equal to 0.2 and Reynolds number equal to 4.3 million based on the mean aerodynamic chord. The presented simulations are two-dimensional and based on RANS for steady jet cases and URANS for pulsed and synthetic cases, compiled with the open-source suite SU2 and adapted for time varying boundary conditions. Numerical results for modified configurations based on the same baseline wing profile considering different leading edges, jet slot height, flap position, blowing mass flow, type and frequency of the jets are presented. Curves of pressure coefficient distribution revealed a substantial influence upstream of the AFC, around the slat and main element. The jet slot height analysis showed that the lift gain is also influenced by the slot size due to the change of the local flow velocity considering the same blowing momentum coefficient. Regarding the jet frequency, no significant differences on the lift coefficients were found between the reduced frequencies F+ equal to 1 and 2. Results of aerodynamic loads showed an improved lift coefficient in relation to the baseline airfoil when pulsed and steady jets are employed. Pulsed jets under square waveform were effective even at high deflected flap condition at 50°, with a significant gain in the lift coefficient of 36%, in relation to the uncontrolled case, combined with a drag reduction of 20%, and a decrease in mass flow up to 49% in relation to the steady jet for the same lift gain. Although sine and square waveform results presented similar improvements for lift, the drag is around 15% higher for the former. When compared with the steady jet case, the mass flow reduction is 36% for the sinewave. Synthetic jets with zero-net-mass-flux proved superior to the baseline conventional multi-element airfoil only with deployed flap at 50°, where a modest lift improvement of 5% was observed.

Simultaneous wing shape and actuator parameter optimization using the adjoint method

Increasing attention to urban air mobility with distributed electric propulsion causes an increased interest in propeller aircraft design and optimization. Various studies have focused on designing and optimizing the aerodynamic performance of wings and propellers. However, existing studies optimized the wing and propeller separately due to the numerical challenges in simulations and optimization. It is not clear to what extent high-fidelity coupled wing-propeller aerodynamic optimization can benefit the propeller aircraft design. As a first step to answer the above question, this study develops the capability to simultaneously optimize the wing shape and actuator parameters. We use a high-fidelity computational fluid dynamics solver to simulate the wing aerodynamics, and the propeller is modeled as an actuator disk. We develop a smoothed actuator disk formulation that allows us to change the actuator's location and radius during the optimization, along with the wing shape. We use the discrete adjoint approach to compute the derivatives and couple them with a gradient-based optimization framework. The benefit of the above adjoint-based optimization framework is that it can use a large number of design variables to allow large design freedom for both wing and actuator. We perform 15 optimizations to evaluate how various actuator parameters impact the wing aerodynamic performance; both single and double actuator configurations are considered. We observe that the spanwise location and outer radius are the two most important actuator parameters, and using more actuator parameters as the design variables result in better performance. For example, optimizing the wing shape while allowing the actuator location and outer radius to move exhibits 11.4% more drag reduction compared with optimizing the wing shape while fixing the actuator parameters. This study serves as the starting point for more detailed high-fidelity coupled wing-propeller aerodynamic optimizations.

Ground effect on the aerodynamics of a flapping wing in forward flight: an experimental study

PurposeGround effect is one of the important factors in the enhancement of wing aerodynamic performance. This study aims to investigate the aerodynamic forces and performance of a flapping wing with the bending deflection angel under the ground effect.Design/methodology/approachIn this study, the wing and flapping mechanism were designed and manufactured based on the seagull flight and then assembled. It is worth noting that this mechanism is capable of wing bending in the upstroke flight as big birds. Finally, the model was examined at bending deflection angles of 0° and 107° and different distances from the surface, flapping frequencies and velocities in forward flight in a wind tunnel.FindingsThe results revealed that the aerodynamic performance of flapping wings in forward flight improved due to the ground effect. The effect of the bending deflection mechanism on lift generation was escalated when the flapping wing was close to the surface, where the maximum power loading occurred.Practical implicationsFlapping wings have many different applications, such as maintenance, traffic control, pollution monitoring, meteorology and high-risk operations. Unlike fixed-wing micro aerial vehicles, flapping wings are capable of operating in very-low Reynolds-number flow regimes. On the other hand, ground effect poses positive impacts on the provision of aerodynamic forces in the take-off process.Originality/valueBending deflection in the flapping motion and ground effect are two influential factors in the enhancement of the aerodynamic performance of flapping wings. The combined effects of these two factors have not been studied yet, which is addressed in this study.

3D Numerical Simulation of a Hovering Hummingbird-inspired Flapping Wing with Dynamic Morphing

Three-dimensional numerical simulations are performed to examine the effects of dynamic wing morphing of a hummingbird-inspired flexible flapping wing on its aerodynamic performance in hovering flight. The range analysis and variation analysis in the orthogonal experiment are conducted to assess the significance level of various deformations observed in the hummingbird wings on wing aerodynamic performance. It has been found that both camber and twist significantly can affect lift, and twist has an even higher significant impact on lift efficiency. Spanwise bending, whether out-of-stroke-plane or in-stroke-plane, has a negligible impact on lift and efficiency, and the in-stroke-plane bending can cause lift to decrease to an extent. Optimal parameters for determining the wing deformations are selected and tested to validate the conclusions drawn in the analysis for the results in orthogonal experiment. Through a comparison study between the optimized wings and the rigid wing, it is found that although the wing flexibility can cause the net force to decrease, the flexible wing used less energy to bring the net force closer to the vertical direction, thereby improving the lift efficiency. This study provides an aerodynamics understanding of the efficiency improvement of the hummingbird-inspired flexible flapping wing.

Effect of paragliding wing dome shape on its aerodynamic characteristics

Double-membrane gliding parachutes (DGP) obtain their wide variety of application, including the solution of cargo transportation problems. This parachute is a flexible canopy, which shape is maintained by ram air. In terms of the aerodynamic performance calculation and analysis when operating, DGP is the most complex aero elastic system. The computation of DPG aerodynamic performance is only possible, utilizing the methods of nonlinear aerodynamics and the nonlinear theory of elasticity methods.This paper investigates the aerodynamic characteristics of stable geometric shapes for various gliding parachutes, taking into account their dome shape both chord-wise and span-wise. Notably, the volumetric parachute profile is modeled by its median surface. The research, conducted by the authors, showed that such an aero elastic model of DGP allows you to obtain results that reflect correctly the qualitative effects of detached and free streamline flow. To solve the problem about the airflow over a gliding parachute, considering its canopy curvature, the method of discrete vortices with closed frames is employed, which allows you to calculate the paragliding wing aerodynamic performance within a wide range of angles of attack. There is also a possibility of flow separation simulation. The ideal incompressible liquid flow over the median surface of a stable shape for a double-membrane gliding parachute is regarded. The parachute fabric porosity is not analyzed, since the upper and lower DGP panels are made of either the low permeable or non-porous fabric. In the separated flow past, the aerodynamic coefficients are identified by time averaging to its large values after computing. The DGP aerodynamic performance computation results are given at a different value of its dome shape, as in the free streamline flow as in the flow separation. The computed coefficients, that allow us to consider the influence of canopy dome shape on its aerodynamic characteristics, are obtained. The proposed technique can be used for operational estimates of aerodynamic forces while designing and planning a pipe experiment.

SHOCKWAVE STUDY ON THE WINGS NACA 0012, NACA 64 - 206, AND NASA SC (2) - 0706 WITH Λ = 15O AT 0.85 MACH NUMBER

Airfoil is used as a basic form on aircraft wings. Airfoil on the wing of the aircraft is used to produce lift that will lift the fuselage into the air. Lifting force results from the difference in pressure between the upper surface and the lower surface of an aircraft wings. In high speed flights shockwave will occur at certain parts of the wing which will adversely affect the aerodynamic performance of the wing. Wing aerodynamic performance at high speeds can be improved in various ways, one of which is by giving a angle to the wing span called a swept angle. This study will use 3D CFD simulation methods using Ansys Fluent. The airfoil used are NACA 0012, NACA 64-206, and NASA SC (2) -0706 with a chord length of 1 m, AR = 5, and λ = 1 with backward swept angle Λ = 15 °. Free stream flow is air flowing with Mach Number = 0,85 at sea level and steady conditions. Based on the simulation results, shock occurs on the upper and lower surfaces for NACA 0012 with Cl = 0 due to symmetric airfoil, whereas shock occurs only on the upper surface for NACA 64-206 and NASA SC (2) - 0706 with a Cl / Cd value of 18.55 ( NACA 64-206) and 20.78 (NASA SC (2) - 0706). This simulation also provides a visual representation of Mach Number contour plots in the middle stretch (Midspan) of the wing and Cl and Cd data.

The Importance of Flapping Kinematic Parameters in the Facilitation of the Different Flight Modes of Dragonflies

To better understand dragonflies’ remarkable flapping wing aerodynamic performance, we measured the kinematic parameters of the wings in two different flight modes (Normal Flight Mode (NFM) and Escape Flight Mode (EFM)). When the specimens switched from normal to escape mode the flapping frequency was invariant, but the stroke plane of the wings was more horizontally inclined. The flapping of both wings was adjusted to be more ventral with a change of the pitching angle that resulted in a larger angle of attack during downstroke and smaller during upstroke to affect the flow directions and the added mass effect. Noticeably, the phasing between the fore and hind pair of wings varies between two flight modes, which affects the wing-wing interaction as well as body oscillations. It is found that the momentum stream in the wake of EFM is qualitatively different from that in NFM. The change of the stroke plane angle and the varied pitching angle of the wings diverts the momentum downwards, while the smaller flapping amplitude and less phase difference between the wings compresses the momentum stream. It seems that in order to achieve greater flight maneuverability a flight vehicle needs to actively control positional angle as well as the pitching angle of the flapping wings.

Effect of Multiscale Endplates on Wing-Tip Vortex

An experimental investigation is conducted to study the effect of multiscale endplates on the wing-tip vortex and wing aerodynamic performance at Reynolds numbers of 215,000 and 244,000 based on the wing mean chord of a NACA 0012 half-span wing. Two groups of endplates are tested. The first group has three different fractal patterns applied along the top edge of the endplate, while the second group has three different two-scale patterns applied to its outboard surface. It is experimentally shown that both geometry modifications produce a weaker and less coherent vortex. Moreover, while a peak in the power spectral density of the fluctuating axial velocity at the vortex core at Strouhal numbers between 3 and 10 is observed for the plain endplates of both groups, it vanishes for the multiscale endplates. This suggests that the multiscale endplates act on the vortex structure, making it less coherent through the production of smaller eddies as evidenced by the velocity spectra. The multiscale endplates also show potential improvements in terms of the wing aerodynamic efficiency, with the maximum being up to 11.1% larger than for the corresponding plain endplate.

Numerical Study on the Effect of an Off-Surface Micro-Rod Vortex Generator Placed Upstream NACA0012 Aerofoil

In this paper, 3D numerical simulations have been carried out to enhance the understanding of a flow over a passive control device composed of micro cylinder with, d/c = 1.34% placed in the vicinity of NACA0012 aerofoil wing, by means of γ–Reθt transition sensitive turbulence model meant to predict the separation induced by transition achieved for aerofoils operating at moderate Reynolds number (Re = 4.45×105). Results show that the separation of the boundary layer has been eliminated by the passive static vortex generator at stall regime due to the injection of free-stream momentum to the boundary layer. The early transition to turbulent state overcomes the local flow deceleration of an adverse pressure gradient and remains sticked to the wall the boundary layer. Furthermore, the wing aerodynamic performance are improved as drag is reduced and lift is enhanced which is straight forward linked to the lift to drag ratio gain that varies from 22.68% to 134.17% at post stall angles of attack.

Kinematics, Deformation, and Aerodynamics of a Flexible Flapping Rotary Wing in Hovering Flight

The Flapping Rotary Wing (FRW) is a micro air vehicle wing layout coupling flapping, pitching, and rotating motions. It can gain benefits in high lift from a fast passive rotating motion, which is tightly related to the passive pitching motion directly caused by wing flexible deformation. Therefore, flexible deformation is crucial for the wing kinematics and aerodynamic performance of an FRW. In this paper, we explored the effect of flexibility on wing kinematics and aerodynamics on the basis of a mechanical FRW model. A photogrammetric method was adopted to capture motion images according to which wing orientations and deformations were reconstructed. Corresponding aerodynamic force was computed using computational fluid dynamic method, and wing kinematics and deformations were used as simulation inputs. The experimental measurements presented the real orientation and deformation pattern of a real FRW. The wing passive deformation of a high-intensity FRW was found to be mainly caused by inertial force, and a linear positive spanwise twist was observed in the FRW. The effects of wing deformation on aerodynamic force production and the underlying mechanism were addressed. Results showed that lift augment, rotating moment enhancement, and power efficiency improvement can be achieved when a wing becomes flexible. Wing spanwise twist mainly accounts for these changes in aerodynamics, and increment in spanwise twist could further contributes to aerodynamic improvement.

Application of the HPCMP CREATETM-AV Kestrel to an Integrated Propeller Prediction

This article presents the results of a computational investigation of an integrated propeller test case using the HPCMP CREATETM-AV Kestrel simulation tools. There is a renewed interest in propeller-driven aircraft for unmanned aerial vehicles, electric aircraft, and flying taxies. Computational resources can significantly accelerate the generation of aerodynamic models for these vehicles and reduce the development cost if the prediction tools can accurately predict the aircraft/propeller aerodynamic interactions. Unfortunately, limited propeller experimental data are available to validate computational methods. An American Institute of Aeronautics and Astronautics (AIAA) workshop was therefore established to address this problem. The objective of this workshop was to generate an open access-powered wind tunnel test database for computational validation of propeller effects on the wing aerodynamics, specifically for wing-tip-mounted propellers. The propeller selected for the workshop has four blades and a diameter of 16.2 in. The wing has a root and tip chord of 11.6 and 8.6 in, respectively. Two different simulation approaches were used: one using a single grid including wind tunnel walls and the second using a subset grid overset to an adaptive Cartesian grid that fills the space between the near-body grid and wind tunnel walls. The predictions of both approaches have been compared with available experimental data from the Lockheed Martin low-speed wind tunnel to investigate the grid resolution required for accurate prediction of flowfield data. The results show a good agreement for all tested conditions. The measured and predicted data show that wing aerodynamic performance is improved by the spinning tip-mounted propeller.