Optimization Of Wing Research Articles

On-Line Black-Box Aerodynamic Performance Optimization for a Morphing Wing With Distributed Sensing and Control

On-Line Black-Box Aerodynamic Performance Optimization for a Morphing Wing With Distributed Sensing and Control

Simultaneous shape and topology optimization of wings

This paper presents a method for simultaneous optimization of the outer shape and internal topology of aircraft wings, with the objective of minimizing drag subject to lift and compliance constraints for multiple load cases. The physics are evaluated by the means of a source-doublet panel method for the aerodynamic response and linear elastic finite elements for the structural response, which are one-way coupled. At each design iteration, a mapping procedure is applied to map the current wing shape and corresponding pressure loads to the unfitted finite element mesh covering the design domain. Wings of small fixed-wing airplanes both with and without a stiffening strut are optimized. The resulting wings show internal topologies with struts and wall-truss combinations, depending on the design freedom of the shape optimization. The lift distributions of the optimized wings show patterns like the ones obtained when performing optimization of wing shapes with constraints on the bending moment at the root.

Structural wing optimisation targeting economical mission performance of a passenger aircraft

AbstractIn an aircraft design, optimisation has become a common practice, especially when structural and aerodynamics interactions are considered. Performance measures often used in an industrial setting include structural weight, drag, lift to drag ratio, fuel burn or maximum range. It is a common practice to evaluate such performance indicators only on a handful of sample points. To achieve a truly economical aircraft design it is necessary to include a fully integrated mission analysis during a multidisciplinary structural optimisation, as there is a strong coupling between a flight behaviour and actual operational conditions of an aircraft. This paper makes a case for a modular approach to a mission analysis implementation that could utilise a variety of physical models and their combinations, offsetting some of the computational demands related to a fully integrated mission analysis and allowing to focus resources where they are needed.

Two-Way Coupled Aero-Structural Optimization of Stable Flying Wings

An aero-structural algorithm to optimize a flying wing in cruise conditions for preliminary design is developed using two-way interaction between the structure and aerodynamics. A particle swarm routine is employed to solve the multi-objective optimization, aiming to reduce the weight of the structure and the aerodynamic drag at the design point. Different shapes are evaluated during the optimization process until the algorithm reaches the optimal wing aspect ratio, taper ratio, angle of incidence, twist angle, swept angle, and airfoil shape, where a six-parameters method is employed to allow reflex airfoils. A main isotropic I-beam models the wing structure. An extended vortex lattice model is employed to model the aerodynamics, along with a high-order panel method with fully coupled viscous interaction. The finite element method is used to solve the flying-wing structure under static loads. An algorithm is developed to iterate between the deflection of the wing and its impact on the aerodynamics until convergence is reached. Different constraints are implemented into the objective function to fulfil the structural criteria and the longitudinal static stability. A comparison against a baseline optimization is carried out, achieving higher efficiency and promising results in elliptical lift distribution, and a high static margin, without the use of non-constant twist. The results suggest that combining both reflex airfoils and sweep with washout is the optimal solution to reduce the drag and weight, keeping the longitudinal static stability criteria for tailless aircraft in the lower end of the transonic regime.

Multi-point aero-structural design optimization of wings considering drag-divergence constraints

Considering the drag-divergence performance as a constraint, this paper presents a multi-point aero-structural design optimization of wings on a wing-body-tail-engine configuration of long-range dual-aisle civil aircraft by using a gradient-based method based on the discrete adjoint method. Firstly, the accuracy of the coupled aero-structural analysis method used in this paper was validated with DLR-F6 wing-body configuration. Then a wing aero-structural design optimization based on a dual-aisle civil aircraft is offered. The drag coefficient of the optimized configuration in every state decreased, which was reduced by 13.67 counts at the cruise condition, the difference in drag coefficient from Mach 0.85 to Mach 0.87 was decreased from 28.52 counts to 18.98 counts, indicating its drag-divergence performance has been improved undoubtedly. Finally, we compared the performance among the multi-point aero-structural optimized configuration, the single-point aerodynamic optimized configuration and the single-point structural optimized configuration. The results show that the multi-point aero-structural design optimization considering drag-divergence performance has great potential to gain a design configuration with better comprehensive and practical performance compared with a single-point optimization in a single discipline.

Multidisciplinary Design and Optimization of Variable Camber Wing with Non-Equal Chord

Since the taper ratio of most wings is not equal to 1, the beam-disk trailing edge deflection mechanism originally designed for the rectangular wing is not fully applicable to the non-equal chord wing. Moreover, it is not only expected that the wing shape can achieve excellent aerodynamic performance under different flight conditions, but one also needs to consider whether the flexible skin can achieve this deformation. This paper used the honeycomb composite structure with zero Poisson’s ratio as the flexible skin of the trailing edge for the variable camber wing, and designed the beam-disk trailing edge deflection mechanism for the non-equal chord wing. The aerodynamic configuration was optimized considering the deformation capability of the skin, and the multidisciplinary design and optimization method of the variable camber wing with non-equal chord was studied. The results show that the aerodynamic performances of the optimized non-equal chord wings were better than before under all given flight conditions. The flexible skin could withstand the strain caused by the maximum deflection of the trailing edge of the wing, and the weight of the wing structure was reduced by 47.1% compared with the initial design when the structural stiffness and strength were satisfied.

적정진료와 병동 설계 최적화

Healthcare providers try to achieve an appropriate level of care, while administrators pursue maximization of hospital utilities. The appropriate level of care may make it hard to maximize the hospital’s utility. This study solves this problem by discovering a wing formation that maximizes the utility when the level of care is appropriate. Consequently, this study demonstrates that the appropriate level of care is different from the level which maximizes the hospital's utility. Specifically, as the wings are segmented, the overtreatment occurs in most care types. The value of maximum total utility is lower when the levels of all types of care are appropriate, compared to when the wings are formed to simply maximize the hospital’s utility. In addition, when the appropriate level of services is provided, the deviation of the hospital’s utility is high depending on the wing formations. Thus, when the appropriate level of care is provided, the hospital managers should identify an optimal wing formation while maximizing the utility. This study can provide a clue for solving such decision-making problems of hospital managers.

3D CFD simulation of the interaction between front wheels&brake ducts and optimised five-element F1 race car front wings under regulations

This investigation analyses the 3D performance of two optimal front wing designs according to the Federation Internationale de l’Automobile 2021 regulations. These regulations imply a 3D five-element front wing, with ground effect and more than 30 design parameters and geometry constrains in practice, which has not been studied before in the literature. The two optimal front wing designs were obtained by parametric optimisation with sampled Kriging interpolation surrogates and a posteriori adjoint-based design refinement. The optimal front wings have been tested on 3D Computational Fluid Dynamic simulations to analyse the generated downforce and flow interaction with the front wheels and brake ducts, as well as the reproduction of influential vortices. Although the parametric design achieved a slightly better downforce-to-drag ratio, the adjoint-based design exhibited a greater ground suction effect, lower pressure distribution on the tire treads, and some deviation of the Y250 vortices to the wheel, which affected the flow over the wheel&brake ducts. This work demonstrated that quick improvements can be achieved starting from 2D analysis and running 3D simulations of relevant parts of the car, which is unaffordable to date for direct 3D simulation in a design space reduced to 17 dimensions and constrained by regulations.

Two-Dimensional-Based Hybrid Shape Optimisation of a 5-Element Formula 1 Race Car Front Wing under FIA Regulations

Front wings are a key element in the aerodynamic performance of Formula 1 race cars. Thus, their optimisation makes an important contribution to the performance of cars in races. However, their design is constrained by regulation, which makes it more difficult to find good designs. The present work develops a hybrid shape optimisation approach to obtain an optimal five-element airfoil front wing under the FIA regulations and 17 design parameters. A first baseline design is obtained by parametric optimisation, on which the adjoint method is applied for shape optimisation via Mesh Morphing with Radial Basis Functions. The optimal front wing candidate obtained outperforms the parametric baseline up to a 25% at certain local positions. This shows that the proposed and tested hybrid approach can be a very efficient alternative. Although a direct 3D optimisation approach could be developed, the computational costs would be dramatically increased (possibly unaffordable for such a complex five-element front wing realistic shape with 17 design parameters and regulatory constraints). Thus, the present approach is of strong interest if the computational budget is low and/or a fast new front wing design is desired, which is a frequent scenario in Formula 1 race car design.

Optimal Elastic Wing for Flapping-Wing Robots Through Passive Morphing

Flapping wing robots show promise as platforms for safe and efficient flight in near-human operations, thanks to their ability to agile maneuver or perch at a low Reynolds number. The growing trend in the automatization of these robots has to go hand in hand with an increase in the payload capacity. This work provides a new passive morphing wing prototype to increase the payload of this type of UAV. The prototype is based on a biased elastic joint and the holistic research also includes the modelling, simulation and optimization scheme, thus allowing to adapt the prototype for any flapping wing robot. This model has been validated through flight experiments on the available platform, and it has also been demonstrated that the morphing prototype can increase the lift of the robot under study by up to 16% in real flight and 10% of estimated consumption reduction.

Analysis of Wind Turbine Pitch 4-Point Contact Bearing

In the field of renewable energy source, the wind power is certainly one of the most important and therefore the industrial and research community are devoting increasing attention to the design, construction, management and maintenance of wind turbines. Due to the relevance, technical, economic and social of this type of installation the correct maintenance is actually a crucial challenge. As in all mechanical engineering applications, numeric models, FEM based, are widely used during both the design step and monitoring on site. In fact, in the frame of Structural Health Monitoring (SHM), the availability of a Digital Twin is fundamental to interpret the signals coming from the sensors and to check the state of wear and the progression of any damage. In general, this numerical tool must have a good accuracy and a great rapidity of response. For this reason it is essential to develop condensed and reliable models of the main elements able to represent the real behaviour of the component without excessively increasing of computational costs. One of the most important element is the pitch variation slewing bearing, which allows the optimal wing orientation. Unfortunately, a complete numeric model of the bearing requires very large dimension and so the real time reply, necessary to SHM, is difficult. In this paper, to overcome this problem, a new simplified model is proposed to represent the array of spheres and its contact condition with the rings of the bearing. The new approach is based on the adoption of a toroid-shaped element replacing the rolling elements. To study this solution, a full-detailed model of a typical slewing bearing for pitch variation has been used to properly set up the contact model and to tune the properties, geometrical and elastic, of the equivalent toroidal body. The main feature of this approach is that, with a relatively low calculation effort, the deformation behaviour and the stress state of the elements connected to the bearing is available in an easy and accurate way. Then, the comparison in real time of the numerical results with the corresponding experimental ones from the site allows to deduce initiation and growth of a damaging process.

Multi-Objective Reliability-Based Partial Topology Optimization of a Composite Aircraft Wing

Reliability-based partial topology optimization (RBPTO) is a new approach for aircraft structural design; however, it brings computational complexity and makes aeroelasticity analysis quite challenging. Therefore, the present study proposed the multi-objective reliability-based partial topology optimization of a composite aircraft wing using a fuzzy-based metaheuristic (MRBPTOFBMH) approach. The objective is to obtain an optimal layout including partial topology and sizing of the aircraft wing structure. Here, an optimal aeroelastic structure is designed by taking into account the uncertain nature of material properties and the permitted transverse displacement. To increase computational efficiency in the design process, a non-probabilistic approach called a possibilistic safety index-based design optimization (PSIBDO) with fuzzy uncertainties is proposed to quantify the uncertainties due to aeroelastic and structural constraints. Various optimum partial topological shapes and sizing of aircraft wing structures with various PSI values in the range of [0.001, 1.0] have been obtained in a single optimization run. These outcomes, including deterministic and reliable optimal aircraft wing structures, demonstrate the high effectiveness of the proposed MRBPTOFBMH technique to alleviate the complexity of unconventional aircraft wing structure design. The findings also reveal the ease in cooperation of the suggested technique with a high-performance multi-objective evolutionary algorithm (MOEA) and its application in real-world multi-objective design optimization (MODO) problems with the least computational requirements against the traditional method’s multiple runs. Furthermore, the proposed methodology can generate potential aircraft wing structures in a range of m = [89.38–127.84] kg, and flutter speed = [285.61–632.78] m/s, that adhere to all the constraints requirements.

Hydrodynamic Design of Fixed Hydrofoils for Planing Craft

The employment of fixed hydrofoils on existing planing craft is becoming a widely investigated topic, thanks to the opportunity of reducing the total drag forces and the consumptions of main engines, with a positive impact also in terms of air pollutant emissions in the atmosphere. The design of fixed hydrofoils for planing craft is investigated after developing the wing hydrodynamic model, capable of capturing the main forces acting on the craft longitudinal plane. An iterative procedure is developed to solve the nonlinear equilibrium equations and detect the minimum thrust configuration of the fixed hydrofoils at the cruise speed. The new iterative procedure allows investigating the entire design space of fixed hydrofoils and detecting the best configuration for both new and existing craft, with a positive impact in terms of time effort amount and design efficiency. A simplified seakeeping model is also developed to evaluate the impact of fixed hydrofoils on the craft hydrodynamics in a seaway. The USV01 planing craft is assumed as reference for the case study. The wing optimization procedure is employed and the seakeeping analysis in the foil-borne mode is subsequently performed by a set of dedicated codes developed in Matlab. The obtained results are discussed and some suggestions for the reliable design of fixed hydrofoils are provided.

Aerodynamic optimization of a VTOL drone using winglets

In this work, an aerodynamic optimization of a VTOL drone wing has been carried out by implementing winglets. A dual methodology has been used employing a CFD study with the open source code OpenFOAM and applying the Vortex Lattice Method with the open source tool XFLR5 for different configurations and wingtips: the original wing, raked wingtips, and blended winglets. A comparison between the two software has been conducted to determine the validity of XFLR5 and to quantify the error in calculating the aerodynamic coefficients and the bending moment. XFLR5 offers the same trends as RANS at a fraction of the cost, allowing the use of XFLR5 for the first stages of design.

합성곱 오토인코더 기반 차원축소모델을 활용한 아음속 유동 조건에서의 에어포일 테이블 예측

Global optimization of wing or rotor blade is non-trivial task due to the computational complexity of 3-dimensional flow simulation. One possible solution is to assume the 3-dimensional flowfield as the summation of 2-dimensional quaisi-steady flowfiled and to calculate the 2-dimensional solution table in advance, which is called airfoil table. However, the computational cost to initially create the database of airfoil table is too expensive, given the wide range of airfoil shape to be explored during the design optimization. SurrogateBRmodeling can be employed to mitigate this problem, but there are two requirements to be considered: 1) airfoil should be properly parameterized so that the design space covers the wide range of airfoil shapes, 2) high-dimensionality of airfoil tables should be effectively reduced to construct surrogate modeling. In this study, these two problems are resolved through variational autoencoder-based generative model and convolutional autoencoder-based reduced-order modeling, respectively. Through the proposed method, the airfoil table is accurately predicted from the unseen airfoil geometries.

A point cloud deep neural network metamodel method for aerodynamic prediction

Aiming to reduce the high expense of 3-Dimensional (3D) aerodynamics numerical simulations and overcome the limitations of the traditional parametric learning methods, a point cloud deep learning non-parametric metamodel method is proposed in this paper. The 3D geometric data, corresponding to the object boundaries, are chosen as point clouds and a deep learning neural network metamodel fed by the point clouds is further established based on the PointNet architecture. This network can learn an end-to-end mapping between spatial positions of the object surface and CFD numerical quantities. With the proposed aerodynamic metamodel approach, the point clouds are constructed by collecting the coordinates of grid vertices on the object surface in a CFD domain, which can maintain the boundary smoothness and allow the network to detect small changes between geometries. Moreover, the point clouds are easily accessible from 3D sensors. The point cloud deep learning neural network, which employs re-sampling technique, the spatial transformer network and the fully connected layer, is developed to predict the aerodynamic characteristics of 3D geometry. The effectiveness of the proposed metamodel method is further verified by aerodynamic prediction and robust shape optimization of the ONERA M6 wing. The results show that the proposed method can achieve more satisfactory agreement with the experimental measurements compared to the parametric-learning-based deep neural network.

A Conceptual Design and Optimization Approach for Distributed Electric Propulsion eVTOL Aircraft Based on Ducted-Fan Wing Unit

The distributed electric propulsion (DEP) eVTOL aircraft has gained rising interest for its promising potential in high-speed cruise compared with conventional tilt-rotor configuration. The aerodynamic interference of the DEP units and wing could become more complicated with a variable thrust in multiple flight conditions. Thus, it requires considerable effort to trade off in the whole design process. Aimed at improving the design efficiency in iteration cycling of a ducted-fan DEP eVTOL aircraft, a conceptual design and optimization approach is proposed in this paper regarding the single-ducted fan and its surrounding wing section as the basic unit. The optimization of the ducted-fan wing (DFW) unit is targeted at improving both hover and cruise efficiencies. After the verification of the span independence of the lift-and-drag coefficients of the DFW unit, a novel DEP eVTOL aircraft conceptual design approach is established based on the vertical meridional plane DFW unit performance analysis. In the following case study, the optimized DFW unit and the conceptual method are applied on a canard configuration, achieving 720 km/h maximum speed, a hovering efficiency of 76.3%, and a 10.7 cruise lift-to-drag ratio. The remarkable performance and concise workflow in the case study both demonstrated the applicability and effectiveness of the proposed design schemes for DEP eVTOL aircraft.

Conceptual Aircraft Empennage Design Based on Multidisciplinary Design Optimization Approach

Within a conventional aircraft design process, the horizontal tail and vertical tail are generally sized via volume coefficient methods. In this manuscript, an improved method for conceptual aircraft tail design based on multidisciplinary design optimization (MDO) approach with stability and control constraints has been developed. To develop this method, first, the tail design requirements have been derived from the regulations and the fundamental functionalities of tail plans. Then, the empennage design is formulated as an MDO problem. Eventually the design optimization of horizontal and vertical tail is combined with the design optimization of the aircraft wing. A test case is presented for concurrent wing and tail plane design, which resulted in more than 9% reduction in aircraft block fuel weight and more than 3% reduction in aircraft maximal takeoff weight, which indicates a great potential for fuel burn and carbon reductions with empennage design optimization at conceptual aircraft design phase.

Structural optimization of an aeroelastic wind tunnel model for unsteady transonic testing

The reduction of loads, ultimately leading to a weight reduction and thus an increase in aircraft performance, plays an important role in the design of modern aircraft. To this end, two aeroelastic tailoring methodologies, independently developed at ONERA and DLR and aiming at load reduction by means of a sophisticated application of composite materials, were applied to a common model geometry. A choice was made in favor of the publicly available NASA Common Research Model (CRM) wing, featuring a comprehensive database with respect to geometry, as well as analytical and experimental research results. The span of the wing half to be investigated was set to 0.55 m, limited by the test section dimensions. While wind tunnel testing was part of ONERA’s workshare, the model building was performed by DLR. This paper at hand focuses on the structural, aeroelastic optimization of the DLR wing. It is based on an optimization framework developed and constantly being enhanced and extended at the DLR - Institute of Aeroelasticity (DLR-AE). The paper describes the consideration of different structural objective functions, structural and aeroelastic constraint combinations, design field considerations, as well as the application of an aero load correction applied in the course of the optimization. The final results consist of the selection of an appropriate fiber type, optimized fiber layers represented as stacking sequence tables for the upper and lower wing skins, and the corresponding optimized jig twist distribution, required for manufacturing the lamination molds; in summary, all data required to start the construction of the wind tunnel model.

Airfoil Optimization with Metaheuristic Artificial Bee Colony Algorithm Supported by Neural Network Trained Using Nasa-Foilsim Data

In this study, the wing profile, which is difficult to calculate and determine, has been optimized with the help of Foilsim data and optimization algorithms. Foilsim data provided by NASA (National Aeronautics and Space Administration) and used by many researchers, especially in developing model airplanes, has been provided to use in aircraft wing shape optimization. Although Foilsim is a very useful simulation program for designers, it cannot be used effectively in optimization processes due to its web environment. Lift coefficient is needed for Lift equation in airfoil shape optimization. Lift coefficient depends on angle, camber, and thickness of airfoil Calculation of Lift coefficient is difficult and needs heavy mathematical equations or real experiments. By using Foilsim data and optimization algorithm (Artificial Neural Networks: ANN, Artificial Bee Colony: ABC), wing angle, camber and thickness values, which are difficult to determine and calculate, were estimated and comparative experiments of the values were made. (Fixed Lift, Fixed Speed, Fixed Wing Area). Experimental results have shown that it is a useful study for airfoil shape optimization. In short, in this study, by using the Foilsim data and the optimization algorithm to provide the lifting force determined by the designer, the most suitable angle, camber, thickness values of the wing, which are difficult to determine and calculate, are determined to enable the production of efficient aircraft. The user enters the desired lift value into the ABC optimization algorithm and finds the required wing properties for the desired lift value.