Compound Wing Research Articles

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.

Predicting Maximum Lift Coefficient for Compound Wings Using Lifting Line Theory

In the context of conceptual design there are low-fidelity lifting line models capable of predicting the maximum lift coefficient of trapezoidal twisted wings. However, more complex geometries like that of the blended-wing–body (BWB) require the introduction of additional geometrical hypotheses. This paper introduces a compound-wing lifting line model that predicts the maximum lift coefficient of geometries like the BWB. Such a model would decrease computation times at early design stages for the BWB. The proposed model is calibrated using Reynolds-Averaged Navier–Stokes (RANS) simulations of a regional BWB geometry near stall with three different twist distributions at low-speed conditions. Application of the calibrated compound wing model on the regional BWB geometry allows to quickly find an optimal twist distribution for this specific configuration: a semiconstant twist distribution on a fraction of the outer wing.

МЕТОД РАСЧЕТА КОЭФФИЦИЕНТА ПОДЪЕМНОЙ СИЛЫ СОСТАВНОГО КРЫЛА ЭКРАНОПЛАНА ПРИ ПОЛЕТЕ У ПОВЕРХНОСТИ ЗЕМЛИ

In the design and characteristics justification of WIG crafts, determination of optimal aerodynamic and moment coefficients and their ratio is still one of the most important problems. Values and ratios of these coefficients provide not only technical tasks performance, but also safe operation of a WIG craft within the framework of AP standards and rules of water transport operation. The paper is devoted to the method of calculating the Cy lift coefficient for the complex compound wing with washers by using the superposition method and verification of calculated data with experimental values. The study was based on TsAGI-876 wing profile characteristics at various relative flight heights.Calculation of the aerodynamic Cy coefficient is performed in several stages:1. Calculation of the aerodynamic Cy coefficient for the center section;2. Calculation of aerodynamic Cy coefficient for the console section;3. Calculation of the total Cy coefficient by using the superposition method.The proposed method of calculation provides an accuracy of up to 93%, which can be considered a satisfactory result for preliminary design of types «B» and «C» WIG crafts.

Wake behind a Compound Wing in Ground Effect

Flow structure is a crucial point for the conceptual design of Wing-in-Ground effect (WIG) crafts. In this study, pressure distributions around a compound wing, velocity and the turbulent intensity distribution in the wake area after trailing of the wing, have been investigated numerically. Computational simulations were completed regarding various angles of attack in-ground-effect. Two parts made up the compound wing: The first composed by one rectangular wing in the center, the second composed by a reverse taper wing, consisting of an anhedral angle at the side. A realizable k-ε turbulent model exhibited the flow field in the physical domain about the wing surface. The numerical results of the compound wing were validated using the data provided by wind tunnel tests. The flow structures around the compound wing were compared with that of a rectangular wing for different conditions. It was found that the pressure distribution on the rectangular wing was weaker than at the lower surface for the compound wing. However, the suction effect on the upper surface of the rectangular wing was higher. Also, the velocity defect and the turbulence level in the wake area was greater behind the compound wing.

Ground boundary layers effect on aerodynamic coefficients of a compound wing with respect to design parameters

The ground viscous effect is an objective that could be an essential parameter for the conceptual design of wing-in-ground effect (WIG) crafts. This study numerically investigates the effect of ground boundary layers on the aerodynamics of a compound wing of a WIG craft. Computational simulations were conducted to evaluate various design parameters such as middle span size, anhedral angle and taper ratio. The flow structure in the physical domain around the wing surface was demonstrated with a realizable k-ε turbulent model. The numerical results of the compound wing for a fixed ground boundary condition were then further validated using experimental data from the wind tunnel. The principal aerodynamic coefficients of compound wings were achieved for both fixed and moving ground conditions. The numerical simulations demonstrated that the ground viscous effect of fixed ground has some effects on lift and drag coefficients and lift-to-drag ratio, including a reduction in the lift coefficient and an increase in the drag coefficient compared with the moving ground. However, the design parameters had a different impact on the ground viscous effect. Nevertheless, the results are predicted to be able to provide a more fine-grained understanding on the ground viscous effect on WIG craft.

Hydro-aerodynamic mathematical model and multi-objective optimization of wing-in-ground effect craft in take-off

Hydro-aerodynamic mathematical model and multi-objective optimization of a popular wing-in-ground effect craft are presented in this research using a hydro-aerodynamic practical method and the genetic algorithm. The primary components of the wing-in-ground effect craft configuration include a compound wing, catamaran hull form and a power-augmented ram platform. The hydro-aerodynamic practical method with low computational time and high accuracy is performed by coupling hydrodynamic and aerodynamic considerations using the potential flow theory in ground effect and the semi-empirical equations proposed for high-speed marine vehicles. The trade-off between hydrodynamic and aerodynamic characteristics makes it difficult to simultaneously satisfy the design requirements of high hydro-aerodynamic performance. In this article, three goals—reduced hump resistance, increased compound wing lift-to-drag ratio and reduced take-off speed—are selected as the objective functions. The longitudinal position of center of gravity, position of outer wing with respect to main wing, power augmented ram platform angle to horizontal and flap angle are also adopted as design variables. Static height stability and the location of the center of gravity with respect to the aerodynamics centers are considered as constraints for the stable flight in ground effect. The optimal solutions of the multi-objective optimization were not unique, rather a set of non-dominated optima, called the Pareto sets, are obtained. As a result of the multi-objective optimization, 25 Pareto individuals are obtained that the naval architects can use in designing wing-in-ground crafts.

Description of the female of Ceromya glaucescens Tachi & Shima (Diptera: Tachinidae) and discovery of unusual sexual dimorphism in this species.

Sexual dimorphism is a phenomenon in which the male and female of a species differ in features of the external morphology such as size, shape, colour, or the development of appendages. In the Diptera, stalked compound eyes, leg modifications and wing patterns are well-known examples of sexual dimorphism (McAlpine 1979; Zeil 1983; Adler & Adler 1991; Meyerrochow & Reid 1994; Wilkinson & Dodson 1996; Sivinski 1997; Baker & Wilkinson 2001; Eberhard 2002; Puniamoorthy et al. 2008). Males and females of sexually dimorphic species are often described as separate species due to the dissimilarity in external characters, thus leading to problems in identification and proper association of the sexes. In contrast to characters that are usually involved in sexual dimorphism, leg chaetotaxy is considered one of the invariable character systems, irrespective of sex, in the tribe Siphonini of the Tachinidae, and is thus widely used in keys to genera and species (O'Hara 1989; Andersen 1996). Species' identification by DNA barcoding has been used in various groups of organisms (Hebert et al. 2003; Ratnasingham & Hebert 2013). In insects, males, usually more easily identified by morphological characters (e.g., postabdominal features) than females, are often used for barcoding. The identification of females will improve as sequence data accumulate, such as data from pairs collected in copula. In this paper, I describe sexual dimorphism in the Japanese endemic species of tachinid fly Ceromya glaucescens Tachi & Shima, 2000 of the tribe Siphonini, and use molecular and morphological data for the identification of this species. Sequence data of C. silacea (Meigen, 1824) are also included for comparison.

Influence of main and outer wings on aerodynamic characteristics of compound wing-in-ground effect

A practical mathematical model with low computational time and good accuracy is applied to investigate the aerodynamic characteristics and static height stability of the compound wing-in-ground effect (WIG). The compound WIG consists of a main wing with low aspect ratio and an endplate, and an outer wing with high aspect ratio. To validate the present mathematical model, a numerical simulation is performed so that numerical results had a good agreement with the experimental data. The analysis shows that the main wing is useful in the extreme ground effect zone and the outer wing enhances performance of the compound WIG in the weak ground effect zone. In order to satisfy the static height stability of the compound WIG it is evaluated by Irodov's criterion. Influence of junction position of outer wing on the main wing is investigated on the static height stability of compound WIG. A comparison of Irodov's criterion shows that static height stability improves with moving the outer wing position backward into the trailing edge of the main wing and this led to a decrease in the tail area. The proposed mathematical model could be appropriate for aerodynamic optimization of WIG crafts with the compound wing.

Design Parametric Study of a Compound Wing-in-Ground Effect. II: Aerodynamics Coefficients

The aerodynamic behavior of the wing-in-ground effect can be affected by its configuration. This configuration is potentially the most influential parameter for the performance and stability of the wing-in-ground effect craft. As a continuation to the authors’ previous works, in this research, the aerodynamic coefficients of the compound wing have been numerically investigated through the design parametric study in ground effect. The aerodynamics performances of the compound wing have been computed and the effects of various design parameters on the lift-to-drag ratio have been discussed in the previous paper. First, this paper validates the prediction method by comparing the lift coefficient of a rectangular wing with NACA 6409 airfoil for different angles of attack with an aspect ratio of 1.25 and ground clearance of 0.15. Then, the aerodynamic coefficients of the compound wing are computed over a range of various design parameters. As expected, all design parameters have effects on the aerodynamic coefficients. However, the effects of design parameters on the aerodynamic behavior of the compound wing are not equal. It was found that the span of the side wing, anhedral angle, and ground clearance have considerable effects on the ram effect pressure and the tip vortex of the compound wing.

Static Stability and Ground Viscous Effect of a Compound Wing Configuration with Respect to Reynolds Number

Static stability is a main issue of a wing-in-ground effect (WIG) craft for safe takeoff and cruise mode of flight. In this study, the effect of ground boundary layers on aerodynamic behaviour and the height static stability of a compound wing ofWIG craft were numerically studied during ground effect. First, the principal aerodynamic coefficients of numerical analysis were validated by experimental data of the compound wing. Then, these coefficients of the compound wing were obtained for fixed and moving ground conditions. Consequently, the numerical results showed that viscous ground had some effects on lift and drag coefficients and lift-to-drag ratio, whereasmoment coefficient and centre of pressure of the compound wing had small variation due to removal of ground boundary layers.The present results clarified that the ground viscous effect can be changed slightly with Reynolds number. Also, the height static stability of the compound wing will be obtained and compared with the rectangular wing one. Based on the current results, the stability of the compound wing was higher than a common rectangular wing. In addition, the height static stability of both wings was strongly affected with ground clearance. It had slight reduction then fluctuated when Reynolds number was increased.

Static Stability of a Compound Wing Configuration in Ground Effect

The height static stability of a wing can be a main concern for conceptual design of wing-in-ground effect (WIG) crafts. In this research, the stability of a rectangular and compound wing was computationally predicted in ground effect. A realizable k-ε turbulent model was used for simulation the flow filed over the wing surfaces. First, the drag coefficient and lift to drag ratio of numerical simulation were validated by experimental data of the rectangular wing. Next, the stability of the compound wing respect to different ground clearances will be determined and compared with rectangular wing. This study illustrated a deep understanding of static stability of present compound wing in ground effect, which eventually can be a guideline for researchers and designers of WIG craft.

English

The wing-in-ground-effect craft is a new means for traveling on rivers, lakes, and at sea between islands. In this study, the effect of boundary layers due to the ground viscous effect on the aerodynamic coefficients of the compound wing of a WIG craft was numerically investigated. The compound wing is divided into three parts, with one rectangular wing in the middle and two reverse taper wings with an anhedral angle at the sides. A realizable k-e turbulent model was used for modeling the flow around the wing area. The computational results of the compound wing for fixed ground were compared with the experimental data. The aerodynamic characteristics of the compound wing were examined via both fixed and moving ground for removing the boundary layers effect of the ground. Accordingly, the numerical result indicated that the lift and drag coefficients and lift to drag ratio are affected by the ground boundary layers while the moment coefficient and center of pressure of the compound wing showed little variation with respect to ground boundary conditions.

Experimental Aerodynamic Characteristics of a Compound Wing in Ground Effect

Wing configuration is a parameter that affects the performance of wing-in-ground effect (WIG) craft. In this study, the aerodynamic characteristics of a new compound wing were investigated during ground effect. The compound wing was divided into three parts with a rectangular wing in the middle and two reverse taper wings with anhedral angle at the sides. The sectional profile of the wing model is NACA6409. The experiments on the compound wing and the rectangular wing were carried to examine different ground clearances, angles of attack, and Reynolds numbers. The aerodynamic coefficients of the compound wing were compared with those of the rectangular wing, which had an acceptable increase in its lift coefficient at small ground clearances, and its drag coefficient decreased compared to rectangular wing at a wide range of ground clearances, angles of attack, and Reynolds numbers. Furthermore, the lift to drag ratio of the compound wing improved considerably at small ground clearances. However, this improvement decreased at higher ground clearance. The drag polar of the compound wing showed the increment of lift coefficient versus drag coefficient was higher especially at small ground clearances. The Reynolds number had a gradual effect on lift and drag coefficients and also lift to drag of both wings. Generally, the nose down pitching moment of the compound wing was found smaller, but it was greater at high angle of attack and Reynolds number for all ground clearance. The center of pressure was closer to the leading edge of the wing in contrast to the rectangular wing. However, the center of pressure of the compound wing was later to the leading edge at high ground clearance, angle of attack, and Reynolds number.

Aerodynamic Behavior of a Compound Wing Configuration in Ground Effect

The aerodynamic coefficients of wing in ground effect can be affected with its design which can be the main parameter for efficiency of wing-in-ground effect craft. In this study, the aerodynamic coefficients of a compound wing were numerically determined in ground effect. The compound wing was divided into three parts with one rectangular wing in the middle and two reverse taper wings with an anhedral angle at the sides. An NACA6409 airfoil was employed as a section of wings. Three dimensional (3D) computational fluid dynamics (CFD) was applied as a numerical scheme. A realizable k-ε turbulent model was used for simulation the turbulent flow around the wing surfaces. For validation purpose, the numerical results of a compound wing with aspect ratio 1.25, at ground clearance of 0.15 and different angles of attack were compared with the current experimental data. Then, the aerodynamic coefficients of the compound wings were computed at various ground clearances and angle of attack of 4°. According to pressure and velocity distribution of air around wing surfaces, ground clearance had considerable effects on ram effect pressure and tip vortex of the compound wing, and aerodynamic coefficients of the compound wing had some improvements as compared with the rectangular wing.

Experimental Investigation of a Wing-in-Ground Effect Craft

The aerodynamic characteristics of the wing-in-ground effect (WIG) craft model that has a noble configuration of a compound wing was experimentally investigated and Universiti Teknologi Malaysia (UTM) wind tunnel with and without endplates. Lift and drag forces, pitching moment coefficients, and the centre of pressure were measured with respect to the ground clearance and the wing angle of attack. The ground effect and the existence of the endplates increase the wing lift-to-drag ratio at low ground clearance. The results of this research work show new proposed design of the WIG craft with compound wing and endplates, which can clearly increase the aerodynamic efficiency without compromising the longitudinal stability. The use of WIG craft is representing an ambitious technology that will help in reducing time, effort, and money of the conventional marine transportation in the future.

Ground Viscous Effect on Aerodynamics of a Compound Wing with Different Reynolds Number

The fly of wing-in-ground effect (WIG) crafts can be affected by ground boundary layers. In this study, the effect of ground viscous on aerodynamic coefficients of a compound wing of WIG craft was numerically investigated. Computational fluid dynamics (CFD) was used for numerical study. The simulations were done respect to different ground clearance and Reynolds number. A realizable k-ε turbulent model was employed for the modelling flow field around the wing area. The numerical results of the compound wing for fixed ground validated with the experimental data. Aerodynamic coefficients of the compound wing were determined for fixed and moving ground. Accordingly, the numerical result presented that lift and drag coefficients and lift to drag ratio has been affected by ground boundary layers while moment coefficient and centre of pressure of compound wing had no more variation due to remove ground viscous. The effect of ground viscous on aerodynamics of the compound wing had a slight changes respect to Reynolds number. CFD can be employed as a good method to find the influence of ground viscous on aerodynamics of WIG crafts.

Design Parametric Study of a Compound Wing-in-Ground Effect. I: Aerodynamics Performance

AbstractThe configuration and service condition of a wing can influence the performance of wing-in-ground effect (WIG) craft. In this study, the aerodynamic performance of compound wings in ground effect was numerically investigated through a parametric design study. The compound wing is divided into three parts with one rectangular wing in the middle and two reverse taper wings with an anhedral angle at the sides. A NACA6409 airfoil was employed as a section of the wing. The design parameters included the span size, anhedral angle, and taper ratio plus two boundary conditions: ground clearance and Reynolds number. The three-dimensional, Reynolds-averaged Navier-Stokes (RANS) equations were solved numerically. A realizable k−e turbulent model was used to compute the effects of the turbulent flow over the wing surface. The computational results of the basic wing were compared with the experimental data of other published works. Next, the aerodynamic performance of the compound wings was computed for variou...

Activin receptor inhibition by Smad2 regulates Drosophila wing disc patterning through BMP-response elements

Imaginal disc development in Drosophila requires coordinated cellular proliferation and tissue patterning. In our studies of TGFβ superfamily signaling components, we found that a protein null mutation of Smad2, the only Activin subfamily R-Smad in the fruit fly, produces overgrown wing discs that resemble gain of function for BMP subfamily signaling. The wing discs are expanded specifically along the anterior-posterior axis, with increased proliferation in lateral regions. The morphological defect is not observed in mutants for the TGFβ receptor baboon, and epistasis tests showed that baboon is epistatic to Smad2 for disc overgrowth. Rescue experiments indicate that Baboon binding, but not canonical transcription factor activity, of Smad2 is required for normal disc growth. Smad2 mutant discs generate a P-Mad stripe that is narrower and sharper than the normal gradient, and activation targets are correspondingly expressed in narrowed domains. Repression targets of P-Mad are profoundly mis-regulated, with brinker and pentagone reporter expression eliminated in Smad2 mutants. Loss of expression requires a silencer element previously shown to be controlled by BMP signaling. Epistasis experiments show that Baboon, Mad and Schnurri are required to mediate the ectopic silencer output in the absence of Smad2. Taken together, our results show that loss of Smad2 permits promiscuous Baboon activity, which represses genes subject to control by Mad-dependent silencer elements. The absence of Brinker and Pentagone in Smad2 mutants explains the compound wing disc phenotype. Our results highlight the physiological relevance of substrate inhibition of a kinase, and reveal a novel interplay between the Activin and BMP pathways.

Numerical Investigation on Aerodynamic Characteristics of a Compound Wing-in-Ground Effect

The performance of a wing-in-ground effect craft depends mostly on its wing configuration. The aerodynamic characteristics of compound wings were numerically investigated during the ground effect. The compound wing was divided into three parts with one rectangular wing in the middle and two reverse taper wings with anhedral angle at the sides. The NACA 6409 airfoil was employed as a section of wings. Three-dimensional computational fluid dynamics was applied as a computational scheme. The k-turbulent model was used for the turbulent ?ow over wing surface. The computational results of a rectangular wing with aspect ratio 1, angle of attack 2 deg, and different ground clearance were compared with the experimental data of other published work. Next, the principal aerodynamic characters of compound wings and a rectangular wing were computed for various ground clearance. The aerodynamic characters of compound wings were compared with the rectangular wing, which has an acceptable increase in lift and decrease in drag. Consequently, the lift-to-drag ratio has a considerable improvement especially in small ground clearance, although their nose-down pitching moment has a little reduction. The performance of the wing improves noticeably for a certain total span of compound wing when the span of the middle part becomes smaller.