Aerodynamic Performance Analysis Research Articles

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.

Analysis of Onset of Transition Region on a Supersonic Wing

Abstract: Climate change is due to the sole effect of global warming, which is an outcome of Green House Gas (GHG) emissions. The aviation industry is considered to be one of the fastest-growing sources of these emissions. Mitigation of these emissions is a challenging task since it requires the entire world to work hand-in-hand. The International Civil Aviation Organisation (ICAO), an international governing body, has come up with a challenging target of net 50% reduction in global aviation emission by 2050, relative to the emission levels in 2005. To achieve this target, there must at least be 2% improvement in fuel efficiency every year. This 2% efficiency improvement is further split into Aircraft technology improvement (1.1%) and Airport infrastructure improvement (0.9%). This research aims to achieve the 2% improvement by aircraft technology improvement. Over the years, it was evidenced that mitigation of skin-friction drag on the wing would contribute to a majority of the fuel efficiency improvement. Hence, the primary aim is narrowed down to wing skin friction drag. The theory of boundary-layer has been studied thoroughly in this research work. Also, the interaction between the shock-waves and boundary-layer will be briefed in this paper as the baseline aircraft is supersonic. As it was understood as understood over the research that extension of the laminar boundary-layer favours the reduction of skin-friction drag, it is the primary objective of this research work. A Computational Fluid Dynamics (CFD) study on the of the wing aerodynamics has been conducted to enhance the performance of the aircraft and ANSYS Fluent has been used to serve this purpose. The results obtained from ANSYS fluent will be validated in one of the NASA’s open-source tool VSPAero which uses Vortex Lattice Method to model the flow. Turbulent Kinetic Energy technique is used to predict the onset of the transition of the flow. Initial study is performed on the 2D aerofoil and one the most optimum aerofoil is obtained, the study is continued in 3D to understand the effect of cross-flow instabilities. Free-stream velocity profile variation is another reliable technique in predicting the transition and will be discussed in the next volume of the paper. Finally, aerodynamic performance analysis will be performed to obtain the best wing configuration.

Analysis of nonlinear aerodynamic performance and passive deformation of a flexible flapping wing in hover flight

The flexibility of insect wings and model wings in flapping-wing micro air vehicles (FWMAVs) is crucial to guarantee an economic flight. Since the wing deformation is bilaterally coupled with the aerodynamic force, conventional simulations on this fluid–structure interaction (FSI) problem mostly build up their models using computational fluid dynamics (CFD) and computational solid dynamics (CSD) methods, which requires high computational costs. Alternatively, an analytical model is proposed here for a quick estimate of the aerodynamic performance and passive deformation on flexible flapping wings. The deformation is simplified into a rigid-body rotation at the wing root, a spanwise twist, and a shortening along the span. The aerodynamic force is approximated by a predictive quasi-steady model and the spanwise twist is modeled using a quadratic polynomial. Results show that the introduction of wing flexibility can attenuate the lift generation due to the negative rotational lift and adverse translation–rotation coupling effect after each stroke reversal. The wing with moderate stiffness is recommended to achieve a high lift. An increase of aspect ratio and root cutoff can also enhance the dimensional lift generation, while the most economic wing design has an aspect ratio around 5 and no root cut-off. More importantly, the increase of flapping frequency can only result in a lift enhancement within certain limits. However, the power consumption keeps increasing as the frequency goes up, indicating a significant breakdown of performance. Our findings can uncover the role of wing flexibility in both insects and FWMAVs and therefore contribute to the design of FWMAVs.

Comparative Aerodynamic Performance Analysis of Camber Morphing and Conventional Airfoils

This paper aims to numerically validate the aerodynamic performance and benefits of variable camber rate morphing wings, by comparing them to conventional ones with plain flaps, when deflection angles vary, assessing their D reduction or L/D improvement. Many morphing-related research works mainly focus on the design of morphing mechanisms using smart materials, and innovative mechanism designs through materials and structure advancements. However, the foundational work that establishes the motivation of morphing technology development has been overlooked in most research works. All things considered, this paper starts with the verification of the numerical model used for the aerodynamic performance analysis and then conducts the aerodynamic performance analysis of (1) variable camber rate in morphing wings and (2) variable deflection angles in conventional wings. Finally, we find matching pairs for a direct comparison to validate the effectiveness of morphing wings. As a result, we validate that variable camber morphing wings, equivalent to conventional wings with varying flap deflection angles, are improved by at least 1.7% in their L/D ratio, and up to 18.7% in their angle of attack, with α = 8° at a 3% camber morphing rate. Overall, in the entire range of α, which conceptualizes aircrafts mission planning for operation, camber morphing wings are superior in D, L/D, and their improvement rate over conventional ones. By providing the improvement rates in L/D, this paper numerically evaluates and validates the efficiency of camber morphing aircraft, the most important aspect of aircraft operation, as well as the agility and manoeuvrability, compared to conventional wing aircraft.

Analysis of aerodynamic performance of high‐speed rotational components for MEMS based turbomachinery considering effects of tip clearance and diabatic heat transfer

AbstractThis paper addresses a fundamental design guideline for rotational components of a micro‐scale gas turbine engine considering an interaction between geometrical structure and aerodynamics. The rotational components of the micro‐scale gas turbine engine may be subjected to the centrifugal stress due to high‐speed rotation. The efficiency of each component is strongly controlled by geometrical clearance between rotational and stationary components, and heat transfer from the turbine to the compressor. Therefore, the elastic deformations due to the centrifugal stress and heat transfer have important role to determine the practical aerodynamic performance of the rotational components. A new sophisticated geometrical structure was introduced to the rotational components to control the elastic deformation and maintain the compressor efficiency that is necessary to hold the minimum requirement for the thermodynamic cycle.

Aerodynamic Performance Analysis and Evaluation of NACA 653-218 Airfoiled Aircraft at Different Blended Winglet Configurations

Aerodynamic Performance Analysis and Evaluation of NACA 653-218 Airfoiled Aircraft at Different Blended Winglet Configurations

Design and aerodynamic performance analysis of a variable geometry axisymmetric inlet for TBCC

Abstract Design and aerodynamic performance analysis of a variable geometry axisymmetric inlet was carried out for tandem scheme turbine-based combined cycle (TBCC) propulsion system. The operation Mach number of the inlet was between 0 and 4. The design point was chosen as Mach number 4.0 in this paper. The determination of external and internal compression and the design method of annular to circle diffuser were illustrated. The inlet was unstart under Ma 3.0 without adjustment. Then, a variable scheme was designed to ensure self-start of the inlet and match the requirement of mass flow rate during the whole flight envelope. And four supports were used to fix the spike. According to the 3D numerical simulations, the total pressure recovery was 0.52 at Ma 4.0 at critical condition and the mass flow rate was consistent with the requirement at different flight Mach number.

Comparative analysis of low velocity vertical axis wind turbine NACA blades at different attacking angles in CFD

Blade elemental design in aerofoil in wind turbine will increase the effectiveness of power generation. Low velocity blades less than 10 m/sec considered for the design optimization in CFD. Present study is a comparison of NACA 0012, NACA4412 and used in low velocity vertical axis wind turbine. The purpose of these research was to analyse the effect on aerodynamic efficiency of the VAWT aerodynamic (maximum rotor energy coefficient) of two NACA-series 4-digit aerodynamic wings, maximum air-foil thickness and maximum camber, and the two variants in parameters on the performance. Angle of increment 0°, 5°, 10°, 15° and velocity variants input from 5, 5.5, 6, 6.5, 7, 7.5, 8 m/s. The pressure distributions at all the relevance have been observed in all the parametric variables. Aerodynamic performance analysis of all air foils with the ANSYS Fluent software was carried out. Included in different angles of approach are also the lift coefficients and drag coefficients. Optimum angles of attack were determined for each profile according to simulations. Final comparison made for both blades with optimal deviations discussed.

Analysis of Aerodynamic Performance of High-Speed Rotational Components for MEMS Based Turbomachinery Considering Effects of Tip Clearance and Diabatic Heat Transfer

Analysis of Aerodynamic Performance of High-Speed Rotational Components for MEMS Based Turbomachinery Considering Effects of Tip Clearance and Diabatic Heat Transfer

Design and aerodynamic performance analysis of a finite span double-split S809 configuration for passive flow control in wind turbines and comparison with single-split geometries

With the previous knowledge of the effectiveness of single-split blades, questions arise about the effectiveness of a double-split configuration on horizontal axis wind turbine. To shed light on this question, a 3-D double-split finite-span configuration with S809 airfoil profile is designed based on the results of unsteady DES simulations of two families of single-split configurations. Firstly, the two 3-D single-split families with four different values of split width are simulated at angles of attack (AOA) up to 25°. Secondly, a finite span double-split model is designed based on the single-split geometries with the highest aerodynamic performances. It has been found that the double-split configuration had the poorest performance for 0°<AOA<17°; however, at 17°<AOA<22°, the double-split model showed the highest performance. Analyzing the time-averaged streamlines showed that excessive injected flow at low AOAs as well as the formation of separation bubbles inside the split channel were two main negative factors that severely reduced the performance of the double-split geometry. Also, findings revealed that using optimum cases of single-split geometry does not result in an optimum double-split geometry. Lastly, considering all findings, a conceptual selective (controlled) flow control method that led to a considerable increase in the aerodynamic performance of the double-split geometry has been proposed and discussed.

Parametric study for optimizing winglet efficiency and comparative analysis of aerodynamic performance of a wing with no winglet and with different types of winglets for lighter aircraft

This study started in July 2020 during the COVID 19 pandemic period to analyze & visually illustrate insights of data of biomedical facilities’ information.

Aerodynamic Performance Analysis of a Variable Sweep Wing for Commercial Aircraft Applications

This study presents a detailed study on wing and its configurations and the morphing techniques for the wing. The morphing methods of the wing such as variable chord, variable span variable cambers have been studied in detail. In this study in detail about the effects of morphable sweep wing, the commercial aircraft wing has been designed and it‘s been modelled using the solid works software. To study the aerodynamic performance the wing, the wing has been analysed in ANSYS Fluent software and the results are interpreted in detail to analyze the effect of wing and its shapes. From the results it‘s been clear that at low speed (Mach=0.8) straight wing has high L/D ratio and at the sonic speed (Mach=1) sweep wing has higher L/D ratio and in Supersonic Speed (Mach=1.2) delta wing tends to have higher L/D ratio. Based on these results the wing can be morphed to the configurations to obtain a better performance in each flight regime. Based on these morphing, aircraft performance can be improved in all flight regimes.

An optimization design method for aerodynamic configuration of high aspect ratio wing

The aerodynamic shape optimization design of the aircraft is to combine the aerodynamic performance analysis of the aircraft with the optimization method, by constantly changing the design shape of the aircraft, its aerodynamic performance is improved to achieve optimal aerodynamic performance under certain constraints. Aircraft aerodynamic shape optimization is a comprehensive design platform that integrates geometric parameterization, moving grid, CFD calculation and optimization algorithms. With the development of computational fluid dynamics (CFD) and the maturity of calculation methods, the role of aerodynamic shape optimization in modern aircraft design becomes more and more important. To this end, an aerodynamic shape optimization design platform based on non-uniform rational B-spline (NURBS) was established. In the optimization process, a mesh deformation method based on radial basis functions is used, and an arbitrary Lagrangian Eulerian method (ALE) is used to describe the unsteady process of the wing. The optimization analysis of the large aspect ratio wing under subsonic conditions has certain reference value for the deformation problem in the aerodynamic shape optimization design.

An aerodynamic performance study and analysis of SD7037 fixed wing UAV airfoil

This work presents an investigation of aerodynamic characteristics of SD7037 low Reynolds number fixed win UAV airfoil. In this work the model design considerations of SD7037 low Reynolds number airfoil has been used to design and analysis. The model design parameters are consistent for the evaluation of aircraft performance and data are recomputed. The aircraft aerodynamic induced drag factor is selected as a parameter for design method and this has been approximately calculated for the airfoil and wing characteristic curves. The results gained by analysis from the designed airframe are suitable for the soft computing requirements. The calculated performance aspects came to be desirable and the soft computing techniques and feature detection program successfully differentiated between the runway and other objects to test automatic take off and landing of UAV. As planned the test for stability of the UAV was performed successfully and the model was self-stabilizing it-self.

Aeroelastic vibration analysis of wind turbine blade with Gurney flap

In this paper, based on the parametric design of 3 D blades including typical cross-section and natural frequency calculation of the equivalent model, an integral method for aerodynamic performance and aeroelastic vibration analysis of blade with Gurney flap is proposed. Parametric design and unstructured grid are used to pre-process the blades with/without the Gurney flap. The discrete aerodynamic performance parameters distribution including the lift, drag, and torsion coefficients calculated by Fluent is fitted by the nonlinear least square method based on the trust-region algorithm, and the natural frequencies of the rotating blade are accurately solved by the equivalent thin-walled beam model and Green’s functions. Based on the aerodynamic performance coefficients and natural frequencies obtained by the accurate calculation above, the aeroelastic response equation of typical cross-section considering local aerodynamic damping matrix is established, and the vibration response of blade in flap and torsion direction is further described. From the analysis results, it can be seen that the Gurney flap structure can not only bring higher lift performance to the blade, but also can reduce the amplitude and vibration range of aeroelastic vibration, improve the aeroelastic stability of the blade, and prove the effectiveness of Gurney flap.

Geometry Design of Coaxial Rigid Rotor in High-Speed Forward Flight

The aerodynamic performance analysis and blade planform design of a coaxial rigid rotor in forward flight were carried out utilizing CFD solver CLORNS. Firstly, the forward flow field characteristics of the coaxial rotor were analyzed. Shock-induced separation occurs at the advancing side blade tip and severe reverse flow occurs at the retreating side blade root. Then, the influence of geometrical parameters of the coaxial rigid rotor on forward performance was investigated. Results show that swept-back tip could reduce the advancing side compressibility drag and elliptic shape of blade planform could optimize the airload distribution at high advance ratio flights. A kind of blade planform combining swept-back tapered tip and nonlinear chord distribution was optimized to improve the rotor efficiency for a given high-speed level flight based on geometric parameter studies. The optimized coaxial rotor increases lift-to-drag ratio by 30% under the design conditions.

Aerodynamic Performance Analysis of Open-Wheel Vehicle: Investigation of Wings Installation Under Different Speeds

An open-wheel vehicle with manual hybrid engine control with formula-like body shape was developed for a learning media at a vocational high school. This study aims to analyze the airflow of over the vehicle body as the effect of wing installation under various vehicle speeds. The investigations are to observe and evaluate the drag coefficient, drag force, lift coefficient, downforce, pressure distribution, streamlines, and velocity vector condition by emphasizing on the results from Computational Fluid Dynamics (CFD) simulation. The study found that installing the front and rear wings contribute to the decrement of drag coefficient 0.07 points and keeping the drag force relatively constant since the projection area changed. The benefit of having wings installed significantly increases the downforce by 334 N, which is 5.51 times higher than without wings in the speed of 150 km/h. However, the engine cover gives a significant obstacle to airflow, reducing the functionality of the rear wing. As such, the presence of the rear wing does not have a substantial effect on reducing the wake region.

Catchment Based Aerodynamic Performance Analysis of Small Wind Turbine Using a Single Blade Concept for a Low Cost of Energy

For low and medium wind conditions, there is a possibility to harness maximum wind potential reducing the cost of energy by employing catchment-based wind turbine designs. This paper aims to study catchment-based small wind turbine aerodynamic performance for improved efficiency and reduced cost of energy. Hence, design parameters are considered based on specific conditions within a catchment area. The bins and statistical methods implemented with Weibull distribution of wind data for selected sites to characterize the wind conditions and a weighted average method proposed to create representative wind conditions implementing a single blade concept. The blade element method was applied using Matlab code (version R2017a, MathWorks Inc., Natick, MA, US) for aerodynamic design and analysis, and computational fluid dynamics employed using ANSYS—Fluent (version 18.1, ANSYS Inc., Canonsburg, PA, USA) for validation. The performance of the designed blade is evaluated based on annual energy production, capacity factor and power coefficient. Then, for site-specific wind conditions, yearly energy production, and relative cost of energy are examined against rated power. Appropriate rated power for a low cost of energy identified and performance measures evaluated for each site. As a result, a maximum power coefficient of around 51.8% achieved at a design wind speed of 10 m/s, and higher capacity factors of 28% and 50.9% respectively attained for the low and high wind conditions at the proposed rated powers. Therefore, for different wind condition sites, enhanced performance at a low cost of energy could be achieved using a single blade concept at properly selected rated powers employing suitable design conditions and procedures.

Numerical analysis of unsteady aerodynamic performance of floating offshore wind turbine under platform surge and pitch motions

The aerodynamic performance of floating offshore wind turbines is extremely complex due to the motions of the floating platform. The surge and pitch motions are the most influential motions among the six degrees-of-freedom motions. In view of this, the aim of this study is to investigate the unsteady aerodynamic characteristics of a floating offshore wind turbine under single (surge or pitch) and combined motions using computational fluid dynamics simulations, In addition, the coupling technique of dynamic mesh and sliding mesh is employed, as well as the unsteady Reynolds averaged Navier-Stokes method. The numerical simulation method in this paper is first validated by comparison to the results of the blade element momentum method and the vortex method. Then, the aerodynamic characteristics of the floating offshore wind turbine under harmonic platform motions with different periods and amplitudes are investigated. The results show that the increase of amplitude and frequency aggravate the fluctuation of the overall aerodynamic performance of the wind turbine. In addition, the combined surge-pitch motion reduces the average power generation indicating that complex platform motions adversely affect the power generation of floating offshore wind turbines.

Design and Optimization of a High-altitude Long Endurance UAV Propeller

This paper presents a propeller designed for a solar unmanned aerial vehicle (UAV) at 22km altitude. The design objective for the 3-blade propeller is to achieve 72% efficiency and 7 N thrust, with 0.5588m diameter propeller rotating at 5500rpm under freestream velocity 50m/s. For such High-Altitude Long Endurance (HALE) flight vehicle, firstly, three low Reynolds number airfoils were assessed by airfoil aerodynamic performance analysis software Profili. As a result, FX 63-137 was selected for the best lift to drag ratio at given altitude. Secondly, a MATLAB program based on Joukowski propeller vortex theory was employed to determine three dimensional configuration of the blades. Then, CFD simulation was carried out on the preliminary design. Furthermore, optimal design method was employed to improve propeller efficiency of the preliminary design using software ISIGHT. Ten variables including chord lengths and blade pitch angles distribution at five spanwise sections were employed. Finally, the optimized propeller with power 467W was obtained, performance satisfying the requirement.