Canard Configuration Research Articles

Canard-configured underwater gliders lift enhancement investigation

ABSTRACT To enhance the lift performance of underwater gliders, this study investigates the application of the canard configuration. Initial experiments conducted in the towing tank confirm the feasibility of the canard configuration in enhancing lift on underwater gliders. Numerical simulations were conducted to determine the effects of canard shape and position on lift. The findings show that the canard vortex induces beneficial upwash, enhancing lift by facilitating flow separation and expanding the negative pressure region on the wing. Specifically, smaller canard sweep angles result in stronger canard vortices, increasing the impact of canards on the wings. A 45° canard sweep angle optimizes both lift and stability for underwater gliders. Positioning canards above and away from wings minimize adverse wake interactions with wing vortices, enhancing glider performance. Compared with the canard-off underwater glider, the lift-to-drag ratio of the canard-on underwater glider was improved by a maximum of 9.8%.

A novel aerodynamic layout design of composite wing unmanned aerial vehicle based on canard configuration

With the development of information technology and technology, more and more cutting-edge industries have come into view of the public, among which one of the most representative technologies is UAV. The emergence of UAVs has reduced the labor cost of some businesses, such as farming, forest fire prevention, maritime patrol and so on. In response to the common problems of long preparation time and poor maneuverability of unmanned aerial vehicles, this paper studies the aerodynamic layout of unmanned aerial vehicles and proposes a new layout. Firstly, the aerodynamic layout of typical UAVs is introduced and compared and analyzed. Then, a new type of compound wing UAV is designed by screening and analyzing the wing, flight analysis, main wing and UAV production process with Reynolds number. Subsequently, simulation experiments were conducted to analyze and optimize the aerodynamic layout performance of the designed UAVs, thereby verifying the reliability of the proposed method.. Finally, the entire content is summarized and analyzed.

A novel aerodynamic layout design of composite wing unmanned aerial vehicle based on canard configuration

With the development of information technology and technology, more and more cutting-edge industries have come into view of the public, among which one of the most representative technologies is UAV. The emergence of UAVs has reduced the labor cost of some businesses, such as farming, forest fire prevention, maritime patrol and so on. In response to the common problems of long preparation time and poor maneuverability of unmanned aerial vehicles, this paper studies the aerodynamic layout of unmanned aerial vehicles and proposes a new layout. Firstly, the aerodynamic layout of typical UAVs is introduced and compared and analyzed. Then, a new type of compound wing UAV is designed by screening and analyzing the wing, flight analysis, main wing and UAV production process with Reynolds number. Subsequently, simulation experiments were conducted to analyze and optimize the aerodynamic layout performance of the designed UAVs, thereby verifying the reliability of the proposed method.. Finally, the entire content is summarized and analyzed.

Low-Boom Design for Supersonic Transport with Canard and Forward-Swept Wings Using Equivalent Area Design Method

Forward-swept wings can be expected to be lower-boom planforms with similar amount of drag as backward-swept wings because of their good lift distributions. In this study, the equivalent area distribution of a ten-seater supersonic forward-swept wing aircraft with a canard was designed to obtain design knowledge for leading boom reduction. The equivalent area distribution of the aircraft was calculated by solving the compressible Euler equation. A feasible target equivalent area distribution was generated based on Darden’s method and compared with the equivalent area distribution. To achieve a closer match in terms of lift and geometry with the target, the main wing planform and the position of the main wing along the body and vertical axes were modified. The low-boom performances were evaluated using the extended Burgers equation. The design results indicated that the forward-swept wing configuration with a canard could divide the single peak of the leading boom into two peaks. Thus, the sonic boom strength of the canard configuration was 2.5 PLdB lower than that of the configuration without the canard wing.

Feasibility study of topology optimization of the control system frame for the missile with canard configuration

PurposeThe purpose of this paper is to describe the new method for optimizing the topology of the control system frame for a canard missile to create its efficient model. Determining the minimum volume of the part risked losing some of the mechanical interfaces and functionality required of the frame. The proposed method must cope with these requirements and include a validation loop of the improved solution proposed by the software. The processing of the mathematical model to a printable form must take into account manufacturing technologies limitations and appropriate curvature continuities to avoid stress concentrations.Design/methodology/approachReal examples from the aerospace industry are presented and the process of determining a prototype is described. The optimization assumed leaving the largest volume of the domain. Strength analyses were performed on both the assembly fasteners and the robust prototype. Once all boundary conditions were validated, topological optimization was performed in the ANSYS environment. The algorithm of the optimization was presented.FindingsObtained fatigues showed the vast potential of topology optimization, efficient method of weight reduction in specific situations. It can be considered as an innovative approach to the manufacturing of products with a structure focused on the best possible correlation of weight and strength, for example of a canard rocket.Originality/valueThe paper introduces precise manufacturing technology of the inner frame for the missile’s control system, which ensures sufficient properties of the material, known as EBM.

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.

Flow Field Study of Effect of Canard Location on Aircraft Aerodynamic Performance

AbstractThe present study investigates the flow behavior due to three different vertical canard locations on the scaled‐down model aircraft by using tuft flow visualization and boundary layer measurements. The aircraft is fabricated with wing airfoil S1223 modified and canard with N22 airfoil using laser cutting technique. Three different color tufts are pasted in wing and canard at 30%, 60%, and 90%. The assembled model is placed inside the subsonic wind tunnel with flow chord Reynolds number 3.8*106, which corresponds to 35 m s−1 of the flow velocity and zero‐degree angle of attack. The boundary layers are measured at 70% of the wing chord with 00 incidence angle at three different span locations, i.e., 30%, 60%, and 90% of the wingspan with varying vertical canard positions. The results are compared with wing alone and it is found that the high wing and high canard configuration are outperformed by providing minimum velocity gradient and hence minimum skin friction drag. The tuft flow visualization also shows the identical results as the boundary layer measurements results. The aerodynamic performance of the high wing high canard configuration is found to be promising, as the skin friction drag coefficient is found to be minimum.

Three-Dimensional Flow Analysis over Canard Configuration in Turbulence Model

The canard has been seen as an ominous aerodynamic object for ages this paper is to shed some more light on the effects of canard configuration on the aircraft’s wings. This flow-field analysis is thus being done using a turbulence model solution to take into the effects of a real-time environment where the vortices from the canard are captured more accurately. The analysis has been done meticulously and made to be as error-free as possible under the guidance of Dr. Yagya Dutta Dwivedi.

Effect of Vertical Canard Location on Skin Friction Drag

This study investigates the viscous skin friction drag generation due to the three different vertical canard locations on the mid winger un-swept aircraft scaled-down model by using boundary layer measurements in the wind tunnel. The N22 airfoil was selected for the canard and the modified S1223 airfoil was selected for the wing. The laser cutting technique was employed for the fabrication of the wing, and canard airfoils, which gave sufficient dimensional accuracy to the model. The canard, wing, and fuselage were fabricated by balsa wood and strengthened by Aluminum stripes. The assembled model is tested in an open subsonic wind tunnel a fixed chord Reynolds number 3.8*106. The boundary layers were measured at 70% of the chord and at three different wingspan locations i.e. 30%, 60%, and 90% with 00 incidence angle. The canards were positioned at three vertical positions one at fuselage reference line (FRL) and the remaining two locations at ± 0.16 c from the FRL. The results were compared with wing-body alone and with three canard locations and found that the high canard configuration outperformed the other two configurations and also wing-body alone configuration as it provides half of the total drag. However, the high canard produces 15% more drag than the wing-body alone at the wing tip (90%).The aerodynamic performance of the high canard configuration was found to be significantly promising for the future use in drones and other small aircrafts.

Two Numerical Studies for Longitudinal Movement of a Canard UAV with Vectored Thrust

This work presents a study concerning the possibilities to improve the longitudinal dynamic of a canard UAV using vectored thrust. It is followed to harness the advantages of canard configuration of UAV and to obtain further a better longitudinal dynamic, able to fulfil more complex missions than canard UAV without vectored thrust. There are tested two methods. The first uses the UAV polars obtained in XFLR 5 and extended, using literature experience, a little bit over the stall angle. By this method is determined the necessary gain between the elevator steering angle and thrust deflection angle in order to maintain the UAV in landing configuration (flaps down) to the optimum angle of attack for landing. Using this method is studied also the effect of vectored thrust in maneuver, in cruise configuration. Step signal on the elevator, thrust and both commands simultaneously are applied on the UAV without and with vectored thrust and are identified the advantages of vectored thrust in this situation. The second method uses the polars of the UAV components obtained in XFLR5, extended independently up to a little bit above each stall angle. By this way is studied the effect of the vectored thrust on the atack angle in horizontal flight for the UAV in cruise configuration. There are obtained horizontal flight parameters (speed, elevator steering, angle of attack and thrust), when vectored thrust is used. It is followed to obtain results for attack angle as high as possible. Both methods are limited by the results obtained in XFLR 5, that can’t determine polars at atttack angles near stall, and for the second method, by the aerodynamic interferences between UAV components.

Surrogate based MDO of a canard configuration aircraft

Surrogate based MDO of a canard configuration aircraft

Design and performance quantification of VTOL systems for a canard aircraft

AbstractThe design and performance quantification of four Vertical Take-Off and Landing (VTOL) architectures for a canard-type aircraft configuration are presented. The aero-structural sizing of the canard configuration and the sizing procedure for the proposed VTOL configurations are described and discussed. The proposed VTOL architectures are based on a range of rotor distances to the centre of gravity, quad- and tri-rotor configurations, retractable front rotors and tilt rear rotors. The aerodynamic performance, total installed power and VTOL system mass were modelled and experimentally validated. The results show that a fully exposed VTOL system penalises the Lift-over-Drag (L/D) ratio significantly relative to a clean configuration. The VTOL system mass can be reduced by up to 32% by using a tilt tri-rotor configuration when compared with an equidistant quad-rotor+pusher configuration. The fraction of installed power usable for forward flight can be increased by up to 80% with a tilt configuration. For the proposed mission, the range can be significantly increased if a tri-rotor tilt configuration is adopted in place of an equidistant quad-rotor+pusher configuration.

Free-Flight Aerodynamic Testing of the Skylon Space Plane

The determination of aerodynamic coefficients for complex high-speed vehicles still requires experimental measurement. This paper details the development of the free-flight measurement technique within the University of Oxford High Density Tunnel. In particular, a novel image processing technique is developed for calculating the position of the model from high-speed video. This study focuses on the measurement of high Reynolds number experimental aerodynamic data for a subscale model of the Skylon space plane of Reaction Engines. Testing was undertaken at a Mach 7 test condition replicating flight at an altitude of 63.5 km. Results for lift, drag, and pitching moment coefficients were obtained over a range of angles of attack. Lift coefficient was nearly linear over the range of angles of attack tested, and drag coefficient was parabolic in shape, but sensitive to model yaw. The vehicle was also shown to be statically unstable, a common characteristic of canard configuration vehicles.

Vortex Dynamics Study and Flow Visualization on Aircraft Model with Different Canard Configurations

Canard configuration on fighter planes is essential for regulating flow and the occurrence of vortex interactions on the main wing, one of which is to delay stall. Stall delays are useful when the aircraft is making maneuvering or short-landing. This study observed the effect of canard configuration on various fighter aircraft models. Fighter models represented the different canard configurations, such as Sukhoi SU-30 MKI, Chengdu J-10, and Eurofighter Typhoon. Water tunnels and computational fluid dynamics (CFD) have made it easier to visualize the flow and aerodynamic forces. The results showed that at a low angle of attack (AoA) < 30°, the Chengdu J-10 and Eurofighter models had the highest lift force coefficient (Cl). When at high AoA, Cl’s highest value occurred on the Sukhoi SU-30 model with a value of 1.45 at AoA 50°. Meanwhile, the highest AoA that still had a high Cl value occurred on the Sukhoi SU-30 and Chengdu J-10 aircraft models, namely at AoA 55° with Cl values more than 1.1. The canard position in the upper of the wing would increase the Cl at low AoA, while the parallel canard position could delay the stall.

The dynamic vortical flow behaviour on a coplanar canard configuration during large-amplitude-pitching

The pitching oscillations (α from 0° to 60°) of a close-coupled coplanar canard configuration were investigated at various reduced frequencies (k=0.0375, 0.075, 0.15, 0.3, 0.6 and 1.2). Both experiments and numerical simulations were carried out to study the differences of dynamic flow characteristics for the configurations with and without a canard (k=0.0375 and 0.6). It was found that lift hysteresis occurred for both a delta wing and canard configuration at various reduced frequencies. At k≥0.6, the orientation of the lift hysteresis loop of the canard became reversed. During the upstroke pitching, a transition phenomenon occurred, in which the canard-wing vortices switched from a counter-rotating vortex system to a co-rotating one. This is due to variation of the effective angle of attack and the canard vortex formed over the lower surface during pitching at k≥ 0.3. As the wing pitched downstroke, the canard vortex and its mirror brought strong downwash flow close to the symmetric plane, which created a high positive pressure region on the upper surface of the wing and eventually led to substantial lift loss.

Optimal design of Vertical-Taking-Off-and-Landing UAV wing using multilevel approach

In order to overcome the propre disadvantages of FW(Fixed-Wing) and VTOL(Vertical-Taking-Off-and-Landing) UAV (Unmanned Aerial Vehicle) and extend its application, the hybrid drone is invested more in recent years by researchers and several classifications are developed on the part of dual system. In this article, an innovative hybrid UAV is raised and studied by introducing the canard configuration that is coupled with conventional delta wing as well as winglet structure. Profited by Computational Fluid Dynamics (CFD) and Response Surface Method (RSM), a multilevel optimization approach is practically presented and concerned in terms of cruise flight mode: adopted by an experienced-based distribution strategy, the total lift object is respectively assigned into the delta wing (90–95%) and canard wing(5–10%) which is applied into a two-step optimization: the first optimization problem is solved only with the parameters concerned with delta wing afterwards the second optimization is successively concluded to develop the canard configuration considering the optimized delta wing conception. Above all, the optimal conceptual design of the delta and canard wing is realized by achieving the lift goal with less drag performance in cruise mode.

Vortex Dynamics Study of the Canard Deflection Angles’ Influence on the Sukhoi Su-30-Like Model to Improve Stall Delays at High AoA

The maneuverability of the Sukhoi Su-30 at very high angles of attack (AoA) was remarkably appealing. Canard angle, in cooperation with aircraft wing, created a flow pattern whereby, in that position, the fighter still had as much lifting force as possible in order not to stall. The behavior of changing canard angle configuration played an essential role in creating the strong vortex core so that it could delay the stall. The study of vortex dynamics at canard deflection angle gave an essential function in revealing the stall delay phenomenon. In this study, one could analyze the flow patterns and vortex dynamics ability of the Sukhoi Su-30-like model to delay stall due to the influence of canard deflection. The used of water tunnel facilities and computational fluid dynamics (CFD) based on Q-criterion has obtained clear and detailed visualization and aerodynamics data in revealing the phenomenon of vortex dynamics. It was found that between 30° and 40° canard deflection configurations, Sukhoi Su-30-like was able to produce the most robust flow interaction from the canard to the main wing. It was clearly seen that the vortex merging formation above the fighter heads was clearly visible capable of delaying stall until AoA 80°.

Influence of the type of the flying apparatus of the "duck" scheme on the distribution of the aerodynamic load on the wing

The change of the lifting force distribution on the wing of canard configuration according to the foreplane type is considered in the paper. Numerous aerodynamic calculations for thirteen different configurations of the foreplane forms (rectangular, box, box with rounded corners, round, romb, V-tail with angle of 90° between lifting surfaces, V-tail with angle of 120° between lifting surfaces, U-tail with angle of 90° between lifting surfaces, U-tail with angle of 120° between lifting surfaces, reversed V-tail with angle of 90° between lifting surfaces, reversed V-tail with angle of 120° between lifting surfaces, reversed U-tail with angle of 90° between lifting surfaces, reversed U-tail with angle of 120° between lifting surfaces) were carried out and their effect on the aerodynamic load distribution on the wing was compared. As a result of the research, it was determined that the U-tail foreplanes have the smallest influence on the distribution of the aerodynamic load on the wing on cruising flight modes. V-tail foreplanes allow you to get larger aerodynamic quality compared to other shapes. The foreplane types that create interference or induction vortices in the wing plane have the most influence on the distribution of aerodynamic load on the wing.The principal results are presented in the graph form for all combinations.

Preliminary design study for a future unmanned cargo aircraft configuration

This paper investigates the suitability of different aircraft configurations for use as an automated air transportation system. The underlying unmanned cargo aircraft, carrying a payload of about 1 ton and operating in the lower air space, is furthermore supposed to have low take-off and landing distances. This work comprises two separate analyses. The first study deals with a group of five different fixed-wing aircraft, containing a conventional configuration, a twin-boom aircraft, a canard configuration, a biplane aircraft, and a box wing configuration. The aircraft are designed for different wing spans and compared with each other in terms of flight performances. Furthermore, the potential benefits of the integration of small electrically driven propellers are investigated. The second study assesses the qualification of a helicopter and a gyrocopter for the transportation task. The gyrocopter is included in these investigations particularly, since its simplicity and its autorotation capabilities bring benefits in terms of maintenance and safety management. This second part investigates flight performance of the rotorcraft, presents their key parameters, and discusses their respective advantages for use as an automated air transportation system. In addition to flight performance evaluations, further design aspects, improving and facilitating the operation of the unmanned cargo aircraft, are taken into account. Finally, a twin-boom aircraft configuration with a wing span of 16 m, a box wing configuration with a wing span of 12 m, and a gyrocopter with small supplementary wings are proposed for the transportation task.

Experimental Study and Neural Network Modeling of Aerodynamic Characteristics of Canard Aircraft at High Angles of Attack

Flow over an aircraft at high angles of attack is characterized by a combination of separated and vortical flows that interact with each other and with the airframe. As a result, there is a set of phenomena negatively affecting the aircraft’s performance, stability and control, namely, degradation of lifting force, nonlinear variation of pitching moment, positive damping, etc. Wind tunnel study of aerodynamic characteristics of a prospective transonic aircraft, which is in a canard configuration, is discussed in the paper. A three-stage experimental campaign was undertaken. In the first stage, a steady aerodynamic experiment was conducted. The influence of a reduced oscillation frequency and angle of attack on unsteady aerodynamic characteristics was studied in the second stage. In the third stage, forced large-amplitude oscillation tests were carried out for the detailed investigation of the unsteady aerodynamics in the extended flight envelope. The experimental results demonstrate the strongly nonlinear behavior of the aerodynamic characteristics because of canard vortex effects on the wing. The obtained data are used to design and test mathematical models of unsteady aerodynamics via different popular approaches, namely the Neural Network (NN) technique and the phenomenological state space modeling technique. Different NN architectures, namely feed-forward and recurrent, are considered and compared. Thorough analysis of the performance of the models revealed that the Recurrent Neural Network (RNN) is a universal approximation tool for modeling of dynamic processes with high generalization abilities.