Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
3.0
2.6
Journals
Aerospace
Special Issues
Aerodynamics Design
share announcement

Aerodynamics Design

A special issue of Aerospace (ISSN 2226-4310). This special issue belongs to the section "Aeronautics".

Deadline for manuscript submissions: closed (1 May 2023) | Viewed by 33773

Special Issue Editors

Dr. Gérald Carrier

E-Mail Website
Guest Editor
The French Aerospace Lab-ONERA, 91120 Palaiseau, France
Interests: aerodynamics; aerodynamics design and multi-disciplinary optimization; new aircraft concepts and technologies investigations
Dr. Michael Meheut

E-Mail Website
Co-Guest Editor
The French Aerospace Lab-ONERA, 91120 Palaiseau, France
Interests: innovative aircraft configurations; blended wing body concepts

Special Issue Information

Dear Colleagues,

Aerodynamics is the discipline that studies the characteristics of fluids flowing around bodies, the resulting forces on these bodies, and the physical phenomena explaining them. Aerodynamics design can thus be defined as the engineering field, and ultimately the art, that leverages aerodynamics and uses them to actually “tailor” flows to produce desirable effects, usually modifying the forces acting on bodies for some specific conditions or ranges of specific conditions. It is therefore intrinsically related to the understanding of flow behavior that is a prerequisite to any successful design. The aerodynamics designer should develop an intimate, almost carnal relationship with flows and be able to “feel” the pressure forces and shear stresses at play in the flow. He can then imagine “what to do”, where to act, and what sort of geometry modifications to apply on the bodies to improve the situation, e.g., alleviate detrimental flow phenomena such as separation, achieve extremal values of some component of aerodynamic forces or moments, or conversely reduce them.

Such an ability to understand the flow and guess how to tailor it is grounded on a strong physical sense and must be educated through personal experiences from flight tests, wind tunnel experiments or from the analysis of numerous numerical flow simulations, or best of all from a combination of these.

This Special Issue is intended to share knowledge, experiences, and methods related to all aspects of aerodynamics design in terms of flow physics, methods, and applications:

  • from low-speed incompressible flows to supersonic/hypersonic flows through transonic aerodynamics;
  • from the experimental investigation of innovative concepts and devices to numerical simulations-based design;
  • from the automotive industry and terrestrial vehicles’ aerodynamics to aircraft, rotorcraft, spacecraft, and missiles’ aerodynamics through aerodynamics design of turbomachinery and “new entrants” (VTOL, supersonic aircraft, etc.);
  • from applied and practical design studies to innovative method and tool development and validation (geometry parameterization, automated grid generation and deformation, and numerical optimization techniques and approaches to design).

Dr. Gérald Carrier
Dr. Michael Meheut
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Aerospace is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • airfoil, blade, clean wing design
  • high-lift devices and control surfaces aerodynamics design
  • aircraft aerodynamics design, aircraft components design (HTP, VTP, belly fairing, winglets, engine pylons, etc.)
  • natural and hybrid laminar flow design
  • car, trucks and train aerodynamics design
  • internal flows application design and flow control devices
  • turbomachinery and propulsive system aerodynamics (turbofans, open rotors, propellers)
  • engine integration design, distributed propulsion, boundary layer ingestion, etc.)
  • rotorcraft, convertible and VTOL/evtol aerodynamics design
  • supersonic and hypersonic vehicles aerodynamics design
  • new aircraft and spacecraft and concepts aerodynamics
  • aerodynamics design applications including unsteady flow phenomena (flutter, buffet, inlet buzz, etc.)
  • advanced aerodynamics designs investigation and validation by experiments
  • geometry modeling and aerodynamic shape parameterization for design
  • topology optimization methods for aerodynamics design
  • automated grid generation, deformation, and adaptation
  • innovative aerodynamics design optimization (direct, surrogate-based, and gradient-based optimization methods, machine learning and IA methods for flow optimization, adjoint methods, and multi-criteria optimization)
  • uncertainty analysis and robust design for aerodynamics design

Published Papers (16 papers)

Download All Papers
Order results
Result details
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:

Research

15 pages, 5428 KiB  
Article
Aerodynamic Characteristics of a Z-Shaped Folding Wing
by Yongchang Huang, Xiangying Guo and Dongxing Cao
Aerospace 2023, 10(9), 749; https://doi.org/10.3390/aerospace10090749 - 24 Aug 2023
Cited by 2 | Viewed by 1208
Abstract
Z-shaped folding wings have the potential to enhance the flight performance of an aircraft, contingent upon its mission requirements. However, the current scope of research on unmanned aerial vehicles (UAVs) with Z-shaped folding wings primarily focuses on the analysis of their folding structure [...] Read more.
Z-shaped folding wings have the potential to enhance the flight performance of an aircraft, contingent upon its mission requirements. However, the current scope of research on unmanned aerial vehicles (UAVs) with Z-shaped folding wings primarily focuses on the analysis of their folding structure and aeroelasticity-related vibrations. Computational fluid dynamics methods and dynamic meshing are employed to examine the folding process of Z-shaped folding wings. By comparing the steady aerodynamic characteristics of Z-shaped folding wings with those of conventional wings, this investigation explores the dynamic aerodynamic properties of Z-shaped folding wings at varying upward folding speeds. The numerical findings reveal that the folding of Z-shaped folding wings reduces the lift-to-drag ratio, yet simultaneously diminishes the nose-down pitching moment, thereby augmenting maneuverability. Concerning unsteady aerodynamics, the transient lift and drag coefficients of the folded wing initially increase and subsequently decrease as the folding angle increases at small angles of attack. Likewise, the nose-down pitching moment exhibits the same pattern in response to the folding angle. Additionally, the aerodynamic coefficients experience a slight decrease during the initial half of the folding process with increasing folding speed. Once the wing reaches approximately 40°~45° of folding, there is an abrupt change in the transient aerodynamic coefficients. Notably, this abrupt change is delayed with higher folding speeds, eventually converging to similar values across different folding speeds. Full article
(This article belongs to the Special Issue Aerodynamics Design)
►▼ Show Figures

Figure 1

22 pages, 63631 KiB  
Article
Study on Aerodynamic Design of the Front Auxiliary Inlet
by Junyao Zhang, Hao Zhan and Baigang Mi
Aerospace 2023, 10(8), 700; https://doi.org/10.3390/aerospace10080700 - 09 Aug 2023
Cited by 1 | Viewed by 1085
Abstract
Submerged inlets have been widely used in advanced aircraft due to their excellent stealth characteristics, but they also suffer from poor aerodynamic performance. To improve the aerodynamic efficiency while maintaining stealth capabilities, this paper proposes a design scheme for a front auxiliary inlet [...] Read more.
Submerged inlets have been widely used in advanced aircraft due to their excellent stealth characteristics, but they also suffer from poor aerodynamic performance. To improve the aerodynamic efficiency while maintaining stealth capabilities, this paper proposes a design scheme for a front auxiliary inlet with an inlet grille. The front auxiliary inlet is connected to the main inlet to form a composite inlet system. The low-energy upstream airflow that accumulates at the inlet is guided by the front auxiliary inlet to flow into the mainstream, resulting in a stable and high-quality airflow. A certain type of cruise missile was used as the research subject, and intake systems with and without front auxiliary inlets were constructed to compare the inlet performance of the two configurations using the CFD method. Additionally, a sensitivity analysis of the main design parameters of the front auxiliary inlet was carried out. The study reveals that a reasonable design of the front auxiliary inlet can prevent low-energy airflow, which accumulates on the missile body surface, from directly entering the inlet. Moreover, the front auxiliary inlet can inject additional mechanical energy into the low-energy airflow, inhibit airflow separation, and improve the uniformity of the flow field. Under cruise conditions, the total pressure recovery coefficient of the front auxiliary inlet configuration increased by 12.39% compared to the model without a front auxiliary inlet configuration. Furthermore, the total pressure distortion index was reduced by 47.24%. Full article
(This article belongs to the Special Issue Aerodynamics Design)
►▼ Show Figures

Figure 1

19 pages, 6409 KiB  
Article
Gust Response of Spanwise Morphing Wing by Simulation and Wind Tunnel Testing
by Zhuoer Yao, Zi Kan and Daochun Li
Aerospace 2023, 10(4), 328; https://doi.org/10.3390/aerospace10040328 - 24 Mar 2023
Cited by 3 | Viewed by 1390
Abstract
The spanwise morphing wing can change its aerodynamic shape to suit its flight environment, thereby having the potential to improve the flight performance of the aircraft, especially in gusty conditions. To investigate the potential of morphing wings, the aerodynamic performance of a spanwise [...] Read more.
The spanwise morphing wing can change its aerodynamic shape to suit its flight environment, thereby having the potential to improve the flight performance of the aircraft, especially in gusty conditions. To investigate the potential of morphing wings, the aerodynamic performance of a spanwise morphing wing with a flapping wingtip in a gust environment was analyzed in this paper. The aerodynamic characteristics of the morphing wing are hard to measure accurately, and thus a wind tunnel test was carried out to study the influences of morphing parameters, such as the morphing length, amplitude and frequency on the gust alleviation effect. The flow mechanism of the designed spanwise morphing wing was analyzed in detail by the instantaneous lift results of the wind tunnel test and the flow field results of the CFD method. The results have shown that with appropriate morphing parameters, the spanwise morphing wing designed in this paper can effectively achieve gust alleviation during flight. The conclusions obtained in this paper can be useful guidance for the design of morphing aircraft. Full article
(This article belongs to the Special Issue Aerodynamics Design)
►▼ Show Figures

Figure 1

17 pages, 67506 KiB  
Article
Influence of Non-Uniform Bluntness on Aerodynamic Performance and Aerothermal Characteristics of Waverider
by Zhipeng Qu, Wanyu Wang, Houdi Xiao, Yao Xiao, Guangli Li and Kai Cui
Aerospace 2023, 10(3), 205; https://doi.org/10.3390/aerospace10030205 - 22 Feb 2023
Cited by 1 | Viewed by 1115
Abstract
The waverider is widely used in hypersonic vehicles with its high aerodynamic performance, but due to the serious aerothermal environment, its sharp leading edge should be blunted. Circular blunt is one of the commonly used aerothermal characteristic protection methods. Circular blunt with larger [...] Read more.
The waverider is widely used in hypersonic vehicles with its high aerodynamic performance, but due to the serious aerothermal environment, its sharp leading edge should be blunted. Circular blunt is one of the commonly used aerothermal characteristic protection methods. Circular blunt with larger diameter can reduce peak heat flux, but at the same time, it will lead to larger drag. The existing research shows that under the same blunt diameter in two-dimensions, the non-uniform blunt can reduce the peak heat flux by 20%, and the difference of drag is small. In this paper, the non-uniform blunt profile is applied to the three-dimensional waverider, and the influence of the non-uniform blunt profile on the aerothermal characteristic performance and aerodynamic performance of the waverider is studied, and the results are compared with those of circular blunt. The numerical simulation is used to compare and analyze the waverider under different angles of attack, flight altitudes, and Mach number. The results show that the peak heat flux of the waverider with non-uniform blunt reduces by about 17% compared with that with circular blunt under a small angle of attack range, Mach 2-10, and a flight altitude of 15–35 km. Meanwhile, when the blunt height/diameter is 20 mm, the aerodynamic performance difference between the two different blunt profiles does not exceed 3% within a 15 degrees angle of attack, Mach 2-10, and flight altitude of 15–35 km. The non-uniform blunt profile can be applied to the design of the three-dimensional waverider. Full article
(This article belongs to the Special Issue Aerodynamics Design)
►▼ Show Figures

Figure 1

13 pages, 3515 KiB  
Article
Aerodynamic Exploration of Corrugated Airfoil Based on NACA0030 for Inflatable Wing Structure
by Qing Zhang and Rongrong Xue
Aerospace 2023, 10(2), 174; https://doi.org/10.3390/aerospace10020174 - 13 Feb 2023
Cited by 2 | Viewed by 1773
Abstract
The flow structures and surface pressure distributions on corrugated airfoils significantly differed from those on a conventional, smooth airfoil. An unsteady, two-dimensional computational simulation was carried out to investigate the flow behavior and associated aerodynamic performance of a group of corrugated airfoils with [...] Read more.
The flow structures and surface pressure distributions on corrugated airfoils significantly differed from those on a conventional, smooth airfoil. An unsteady, two-dimensional computational simulation was carried out to investigate the flow behavior and associated aerodynamic performance of a group of corrugated airfoils with different levels of waviness at angles of attack from 0° to 20° with an interval of 2° at a low Reynolds number regime (Re = 1.2 × 105) and were quantitatively compared with those of its smooth counterpart. Time-averaged aerodynamic coefficients demonstrated that the corrugated airfoils have a lower lift and higher drag because of trapped vortices in the corrugations. The pressure drag of the corrugated airfoils was greater than that of the smooth airfoil. In contrast, the viscous drag of the corrugated airfoils was smaller than that of the smooth airfoil because the recirculation generated in the corrugation could reduce the viscous drag. The averaged velocity gradient in the boundary layer showed that the thickness of the boundary layer increased significantly for the corrugated airfoils because of recirculating flow caused by the small-standing vortices trapped in the valley of corrugations. The smoother the corrugated surface, the closer the aerodynamic characteristics are to those of the smooth airfoil. Full article
(This article belongs to the Special Issue Aerodynamics Design)
►▼ Show Figures

Figure 1

21 pages, 11242 KiB  
Article
Rapid Blade Shape Optimization for Contra-Rotating Propellers for eVTOL Aircraft Considering the Aerodynamic Interference
by Nanxuan Qiao, Tielin Ma, Jingcheng Fu, Ligang Zhang, Xiangsheng Wang and Pu Xue
Aerospace 2023, 10(1), 54; https://doi.org/10.3390/aerospace10010054 - 05 Jan 2023
Cited by 2 | Viewed by 2536
Abstract
The rising interest in the evolvability of electric vertical takeoff and landing (eVTOL) promises substantial potential in the field of urban air mobility (UAM). Challenges in energy storage density and geometry restriction both emphasize the propeller efficiency for endurance and takeoff weight, whereas [...] Read more.
The rising interest in the evolvability of electric vertical takeoff and landing (eVTOL) promises substantial potential in the field of urban air mobility (UAM). Challenges in energy storage density and geometry restriction both emphasize the propeller efficiency for endurance and takeoff weight, whereas the contra-rotating propellers (CRP) advantage is balancing high thrust and efficiency over a single propeller. The aim of this paper is twofold: (i) to present a novel rapid CRP blade shape optimization framework and (ii) to study the impact of the dual propellers revolution speed allocations on the overall CRP power efficiency. The core of the framework is the blade element momentum theory (BEMT)-based blade shape optimization considering the wake effect of the upper propeller by the rotational CFD (computational fluid dynamics) actuator-disc simulation method. The results show that for the same thrust, the optimized CRP at the equal revolution speed is superior to the original (upper-lower-identical) one by 5.9% in thrust-to-power ratio. The overall efficiency can be additionally lifted by 5.3% when the dual propellers share similar torques. By excluding the integral propeller CFD simulation and empirical parameters estimation, the framework enables the swift obtaining of an optimized CRP scheme while maintaining robustness as well. Full article
(This article belongs to the Special Issue Aerodynamics Design)
►▼ Show Figures

Figure 1

27 pages, 8913 KiB  
Article
A Fast Aerodynamic Model for Aircraft Multidisciplinary Design and Optimization Process
by Frédéric Moëns
Aerospace 2023, 10(1), 7; https://doi.org/10.3390/aerospace10010007 - 22 Dec 2022
Cited by 3 | Viewed by 2011
Abstract
A multidisciplinary design analysis and optimization process is developed at ONERA for the design of tube and wing and blended wing–body aircraft configurations. This process is composed of different disciplinary modules (geometry, propulsion, aerodynamics, structure, handling qualities and flight mission), and the overall [...] Read more.
A multidisciplinary design analysis and optimization process is developed at ONERA for the design of tube and wing and blended wing–body aircraft configurations. This process is composed of different disciplinary modules (geometry, propulsion, aerodynamics, structure, handling qualities and flight mission), and the overall process considers different fidelity levels for these modules at each step of the design process. This article describes the low-fidelity aerodynamic module used during the preliminary design optimization process. Analytical formulations retained for lift and drag components are presented in the first part. Then, the performances estimated by the aerodynamic module on some reference configurations are compared with both numerical and experimental data, showing a quite good agreement for both tube and wing and blended wing–body configurations not only for global performance but also for individual drag components. Full article
(This article belongs to the Special Issue Aerodynamics Design)
►▼ Show Figures

Figure 1

27 pages, 18836 KiB  
Article
Investigation of Improvement Design on Aileron Surface Flow State of High Lift Configuration in BWB
by Xiaotian Niu, Jie Li, Heng Zhang and Zhao Yang
Aerospace 2022, 9(12), 842; https://doi.org/10.3390/aerospace9120842 - 17 Dec 2022
Cited by 1 | Viewed by 2666
Abstract
The aileron is one of the most important tools for adjusting the roll attitude of the aircraft, but the surface flow state of the aileron is likely to be affected by high-lift devices. In this paper, by using computational fluid dynamics (CFD) simulations [...] Read more.
The aileron is one of the most important tools for adjusting the roll attitude of the aircraft, but the surface flow state of the aileron is likely to be affected by high-lift devices. In this paper, by using computational fluid dynamics (CFD) simulations and wind tunnel tests, the Krueger flap effects on the surface flow state of ailerons in a typical blended wing body civil aircraft were investigated. In order to increase the lift, deflecting the Krueger flap makes the flow separation occur on the aileron surface of BWB civil aircraft. This way of the surface stall that the flow separation in the aileron zone first appears at the wing tip rather than at the wing root is unreasonable for civil aircraft. For the above problem, a sensitivity analysis of the design parameters of the Krueger flaps was carried out. The results indicate that the angle of the outboard Krueger flap mainly affects the flow separation of the ailerons. Its length affects the pitch moment tremendously, while its width slot affects the pitch moment slightly. Finally, the design principles of the BWB Krueger flap for the improvement aileron surface flow state were proposed, and the redesign of the BWB high lift configuration significantly improved the flow state of the aileron zone at a minimal cost of aerodynamic characteristics without losing the existing great aerodynamic performance. Full article
(This article belongs to the Special Issue Aerodynamics Design)
►▼ Show Figures

Figure 1

16 pages, 6220 KiB  
Article
Numerical and Experimental Analysis of Drag and Lift Forces on a Bullet Head
by Abdullah Khan, Imran Shah, Shahid Aziz, Muhammad Waqas, Uzair Khaleeq uz Zaman and Dong-Won Jung
Aerospace 2022, 9(12), 816; https://doi.org/10.3390/aerospace9120816 - 12 Dec 2022
Cited by 5 | Viewed by 3266
Abstract
The bullet head plays a principal role in the modern enlargement of an efficient bullet. A bullet’s main design parameters depend upon the lift and drag forces acting on the head. The factors in a bullet’s shape design that affect bullets’ lift and [...] Read more.
The bullet head plays a principal role in the modern enlargement of an efficient bullet. A bullet’s main design parameters depend upon the lift and drag forces acting on the head. The factors in a bullet’s shape design that affect bullets’ lift and drag forces are essential in aerodynamics, especially in ballistics. Therefore, the effect of wind on the lift and drag forces acting on the bullet, and the role of the bullet head to allow the bullet to travel efficiently through the wind, need to be investigated. This work discusses the parameters that affect the lift and drag force on the bullet. Simulations are performed in Ansys Fluent by varying the key parameters of the bullet head, i.e., the length and angle of attack, while keeping the air velocity at 5.2 m/s. The simulation outcome shows that the size of the bullet and the angle of attack are important factors related to the drag force. Therefore, this work predicts the inspection of a bullet under distinct wind conditions. An evaluation is performed to scrutinize the effect of design factors on the system execution of the bullet and its constructive flight path. It is concluded that when increasing the length of the bullet and its angle of attack (AOA), the drag force and lift forces increase drastically, contributing to the inefficiency of the bullet’s accuracy and penetrating power. A new design is also proposed in which the drag forces are reduced to the minimum. Full article
(This article belongs to the Special Issue Aerodynamics Design)
►▼ Show Figures

Figure 1

23 pages, 15694 KiB  
Article
Sensitivity Analysis of Geometrical Parameters to the Flow of Pre-swirl System after Turbine Blade Fracture
by Gang Zhao, Tian Qiu and Peng Liu
Aerospace 2022, 9(12), 783; https://doi.org/10.3390/aerospace9120783 - 01 Dec 2022
Cited by 1 | Viewed by 1087
Abstract
The pre-swirl stator-rotor system is a common and important structure in gas turbines, and its main function is to provide cold air to the turbine blades with a low relative total temperature. Under normal conditions, the boundaries of the system are symmetrical and [...] Read more.
The pre-swirl stator-rotor system is a common and important structure in gas turbines, and its main function is to provide cold air to the turbine blades with a low relative total temperature. Under normal conditions, the boundaries of the system are symmetrical and there is sufficient margin for each blade. However, a fracture of turbine blades can upset this balance, resulting in potentially different cold-air conditions for each blade. Therefore, to ensure the safety of the other blades after a single-blade break, it is necessary to know the cold-air distribution law of the system after a blade fracture. In this paper, the effects of geometric parameters (including pre-swirl angle, α; the area ratio of nozzles and holes, ξ; gap ratio, G; and radius ratio of nozzle and hole, δ) of a pre-swirl stator-rotor system on the mass-flow-rate ratio, η; total-pressure-loss coefficient, Cp; discharge coefficient of holes, Cd; and adiabatic effectiveness, Θad, are investigated by numerical simulation with a single blade fractured. The results show that most of the geometric parameter changes do not increase ηhole_0. Moreover, measures to increase the influence of pre-swirl nozzles can reduce the influence of blade fracture on mass flow distribution, such as larger α, smaller ξ, and smaller δ. As for Cp, Cd, and Θad, they are more sensitive to changes in α and ξ. For the pre-swirl system, to avoid more serious safety problems caused by individual blade fracture, the designer should make every effort to reduce the unevenness of the cold-air distribution. Increasing the effect of the nozzle could serve the aim, but it may increase the volatility of the flow. The pre-swirl nozzle of the leaf grille type is a good option to address flow fluctuations. Full article
(This article belongs to the Special Issue Aerodynamics Design)
►▼ Show Figures

Figure 1

24 pages, 17747 KiB  
Article
Flow Mechanism of a New Concept Transonic Tandem Fan Stage under the Design and Off-Design Conditions
by Chuangxin Zhou, Shengfeng Zhao and Xingen Lu
Aerospace 2022, 9(11), 686; https://doi.org/10.3390/aerospace9110686 - 03 Nov 2022
Viewed by 1593
Abstract
A detailed numerical simulation of a transonic tandem fan stage was conducted, and the change rule of the flow structure inside the fan stage under the design and off-design conditions was discussed to determine the internal flow mechanisms. The results demonstrate that the [...] Read more.
A detailed numerical simulation of a transonic tandem fan stage was conducted, and the change rule of the flow structure inside the fan stage under the design and off-design conditions was discussed to determine the internal flow mechanisms. The results demonstrate that the total pressure ratio of the fan stage steadily increases with the rotating speed, exhibiting an approximately quadratic growth rate. The peak efficiency reaches the maximum at 80% design speed and rapidly declines under the overspeed condition. Furthermore, the peak efficiency point for different rotating speeds was investigated. The changes in the flow features, such as shock wave/boundary layer interaction and radial migration of low-energy fluids, mainly determine the isentropic efficiency at the higher span. At the middle-lower span, higher or lower inflow relative Mach number increases the flow loss. Moreover, the strength of the tip vortex and wake affect the flow loss at the lower span, while the radial motion of the former flow structure dominated by the equivalent inertial force is another essential factor. Under the high-speed condition, the gain of a high-throughflow fan on choke mass flow can be exhibited. However, the throat position causes an abnormal change under the overspeed condition. Full article
(This article belongs to the Special Issue Aerodynamics Design)
►▼ Show Figures

Figure 1

15 pages, 3520 KiB  
Article
Lagrange Optimization of Shock Waves for Two-Dimensional Hypersonic Inlet with Geometric Constraints
by Yuling Li, Lianjie Yue, Chengming He, Wannan Wu and Hao Chen
Aerospace 2022, 9(10), 625; https://doi.org/10.3390/aerospace9100625 - 20 Oct 2022
Cited by 1 | Viewed by 1264
Abstract
The present paper focuses on the Lagrange optimization of shock waves for a two-dimensional hypersonic inlet by limiting the cowl internal angle and inlet length. The results indicate the significant influences of geometric constraints on the configuration of shock waves and performances of [...] Read more.
The present paper focuses on the Lagrange optimization of shock waves for a two-dimensional hypersonic inlet by limiting the cowl internal angle and inlet length. The results indicate the significant influences of geometric constraints on the configuration of shock waves and performances of an inlet. Specifically, the cowl internal angle mainly affects the internal compression section; the inlet length affects both the internal and external compression sections where the intensity of internal and external compression shock waves shows a deviation of equal. In addition, the performances of optimized inlets at off-design points are further numerically simulated. A prominent discovery is that a longer inlet favors a higher total pressure recovery at the positive AOA; conversely, a shorter inlet can increase the total pressure recovery at the negative AOA. Full article
(This article belongs to the Special Issue Aerodynamics Design)
►▼ Show Figures

Figure 1

22 pages, 5410 KiB  
Article
Simplified Model for Forward-Flight Transitions of a Bio-Inspired Unmanned Aerial Vehicle
by Ernesto Sanchez-Laulhe, Ramon Fernandez-Feria and Anibal Ollero
Aerospace 2022, 9(10), 617; https://doi.org/10.3390/aerospace9100617 - 18 Oct 2022
Cited by 5 | Viewed by 1842
Abstract
A new forward-flight model for bird-like ornithopters is presented. The flight dynamics model uses results from potential, unsteady aerodynamics to characterize the forces generated by the flapping wings, including the effects of the dynamic variables on the aerodynamic formulation. Numerical results of the [...] Read more.
A new forward-flight model for bird-like ornithopters is presented. The flight dynamics model uses results from potential, unsteady aerodynamics to characterize the forces generated by the flapping wings, including the effects of the dynamic variables on the aerodynamic formulation. Numerical results of the model, which are validated with flapping flight experimental data of an ornithopter prototype, show that state variables such as the pitch angle and the angle of attack oscillate with the flapping frequency, while their mean values converge towards steady-state values. The theoretical analysis of the system shows a clear separation of timescales between flapping oscillations and transient convergence towards the final forward-flight state, which is used to substantially simplify both the interpretation and the solution of the dynamic equations. Particularly, the asymptotic separation into three timescales allows for dividing the problem into a much simpler set of linear equations. The theoretical approximation, which fits the numerical results, provides a direct look into the influence of the design and control parameters using fewer computational resources. Therefore, this model provides a useful tool for the design, navigation and trajectory planning and control of flapping wing UAVs. Full article
(This article belongs to the Special Issue Aerodynamics Design)
►▼ Show Figures

Figure 1

21 pages, 14446 KiB  
Article
A Novel Decomposition Method for Manufacture Variations and the Sensitivity Analysis on Compressor Blades
by Baojie Liu, Jiaxin Liu, Xianjun Yu and Guangfeng An
Aerospace 2022, 9(10), 542; https://doi.org/10.3390/aerospace9100542 - 23 Sep 2022
Cited by 3 | Viewed by 1365
Abstract
A high accuracy blade manufacture variation decomposition method was proposed to decompose the manufacture variations of compressor blades to systematic variation and non-systematic variation, which could help to clearly quantify the statistical characteristics of the effect of manufacture variations on the blade aerodynamic [...] Read more.
A high accuracy blade manufacture variation decomposition method was proposed to decompose the manufacture variations of compressor blades to systematic variation and non-systematic variation, which could help to clearly quantify the statistical characteristics of the effect of manufacture variations on the blade aerodynamic performance and to guide the modeling of manufacture variations in geometric uncertainty quantification and robust design studies. By conducting the decomposition of manufacture variations with 100 newly manufactured blades of a high-pressure compressor, it was found that the systematic variation could be modeled by using seven representative blade geometry design parameters well and the mean value of the non-systematic variation, which is determined by using the difference between the measured blade and systematically reconstructed blade, is close to zero. For the standard deviation of decomposed manufacture variations, the non-systematic variation accounts for about 40% of the whole, indicating that the systematic variation is the major component of the manufacture variation. However, based on statistical analysis and sensitivity analysis of the effects of the two types of manufacture variations on blade aerodynamic performance, it was found that the mean deviation of the blade loss mainly derives from systematic variations, and the loss dispersion caused by non-systematic variations is significantly greater than that caused by systematic variations. Furthermore, the blade loss at the high incidence angle is most sensitive to the inlet metal angle which belongs to the systematic variation. Meanwhile, the non-systematic variation near the leading-edge is the most sensitive, and it contributes to most of the performance disperse but only accounts for a geometric variation of about 0.45%. Full article
(This article belongs to the Special Issue Aerodynamics Design)
►▼ Show Figures

Figure 1

18 pages, 5708 KiB  
Article
Development and Validation of a Novel Control-Volume Model for the Injection Flow in a Variable Cycle Engine
by Ruoyu Wang, Xianjun Yu, Ke Zhao, Baojie Liu and Guangfeng An
Aerospace 2022, 9(8), 431; https://doi.org/10.3390/aerospace9080431 - 05 Aug 2022
Cited by 2 | Viewed by 1673
Abstract
The variable area bypass injector (VABI) plays a crucial role in variable cycle engines by regulating the flow mixing process in complex bypass ducts, and low-dimensional theoretical models are the key to revealing its working mechanism while estimating its aerodynamic performance. An improved [...] Read more.
The variable area bypass injector (VABI) plays a crucial role in variable cycle engines by regulating the flow mixing process in complex bypass ducts, and low-dimensional theoretical models are the key to revealing its working mechanism while estimating its aerodynamic performance. An improved VABI model using the control volume method is established, through which the feature parameters that determine the VABI aerodynamic performance are summarized. To acquire an accurate prediction of the injection ratio, a calibration item is introduced to the governing equations to consider the static pressure discrepancy on the mixing plane, and a numerical database is developed to obtain the calibration item. Results show that the aerodynamic parameters that determine the VABI performance include the bypass total pressure ratio, bypass backpressure, and the injection ratio, while the injection angle and the VABI opening area also influence the injection flow characteristics. The injection ratio is increased by reducing the bypass total pressure ratio, decreasing the bypass backpressure, and closing the VABI. Numerical validation shows that the calculation error of the improved model is generally below 3%. The improved VABI model is then validated by a well-arranged experiment, for which the annular flow is simplified into a rectangular duct flow with an error of less than 5%. The experimental validation also proves the accuracy of the model. Full article
(This article belongs to the Special Issue Aerodynamics Design)
►▼ Show Figures

Figure 1

22 pages, 12259 KiB  
Article
Numerical Investigation of the Aerofoil Aerodynamics with Surface Heating for Anti-Icing
by Bowen Li, Qiangqiang Sun, Dandan Xiao and Wenqiang Zhang
Aerospace 2022, 9(7), 338; https://doi.org/10.3390/aerospace9070338 - 24 Jun 2022
Cited by 5 | Viewed by 2219
Abstract
The aerodynamics of an aerofoil with surface heating was numerically studied with the objective to build an effective anti-icing strategy and balance the aerodynamics performance and energy consumption. NACA0012, RAE2822 and ONERA M6 aerofoils were adopted as the test cases and the simulations [...] Read more.
The aerodynamics of an aerofoil with surface heating was numerically studied with the objective to build an effective anti-icing strategy and balance the aerodynamics performance and energy consumption. NACA0012, RAE2822 and ONERA M6 aerofoils were adopted as the test cases and the simulations were performed in the subsonic flight condition of commercial passenger aircraft. In the first session, the numerical scheme was firstly validated with the experimental data. A parametric study with different heating temperatures and heating areas was carried out. The lift and drag coefficients both drop with surface heating, especially at a larger angle of attack. It was found that the separation point on the upper surface of the aerofoil is sensitive to heating. Higher heating temperature or larger heating area pushes the shock wave and hence flow separation point moving towards the leading edge, which reduces the low-pressure region of the upper surface and decreases the lift. In the second session, the conclusions obtained are applied to inform the design of the heating scheme for NACA0012. Further guidelines for different flight conditions were proposed to shed light on the optimisation of the heating strategy. Full article
(This article belongs to the Special Issue Aerodynamics Design)
►▼ Show Figures

Figure 1

Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
 
Displaying articles 1-16
Back to TopTop