Designing and modelling of a high-performance racing glider and evaluating its aerodynamic performance.

Abstract

Although conceptual tools for designing glider winglets had been of little utility, basic procedures were employed to create winglets that gradually gained recognition as improving overall rigid airship performance. An enhanced winglet design process has indeed been created to augment these gains. This approach contains a thorough constituent drag buildup, as well as the ability to interpolate input airfoil drag and moment data over a wide variety of operating lift coefficients, Reynolds numbers, and flaps settings range. The initial prediction of induced drag is made using a rather quick multi-lifting horizontal analysis. In the latter phases of the design process, a complete model for the wing has been simulated in the OPENVSP software. For both straight and tail wings, the drag estimations are employed to compute the Mach number. The expected performance again cross checked and simulated on XLFR5 software. Using the NACA 5210 profile have been used for the high performance glider. For both front wings and tail wings high-performance gliders, the design scenarios described here show that winglets could provide a minor but significant performance benefit across most of the operational range.

Contents

Abstract. 2

Contents. 3

Introduction. 5

Aims and Objectives. 5

Literature review.. 6

Project Planning. 8

Tasks. 8

Methodology. 8

HOW TO USE XLFR5. 12

Concept Design. 12

Simulation and Analysis. 19

Discussions. 22

Conclusions. 27

Bibliography. 27

GLOSSARY. 28

List of Figure

Figure 1 3D model in OpenVSP……………………………………………………………………………………………………………. 14

Figure 2 VSP AERO……………………………………………………………………………………………………………………………. 15

Figure 3 CL vs. Wake Iteration…………………………………………………………………………………………………………….. 16

Figure 4 Initial Tail Sizing…………………………………………………………………………………………………………………….. 17

Figure 5 Wing calculation data at 11 degree……………………………………………………………………………………………. 19

Figure 6 Plot……………………………………………………………………………………………………………………………………. 19

Figure 7 Cp of Wing…………………………………………………………………………………………………………………………… 20

Figure 8 Plot of Cp…………………………………………………………………………………………………………………………….. 20

Figure 9 Gantt chart………………………………………………………………………………………………………………………….. 21

List of Table

No table of figures entries found.

Nomenclature

b             span

c              wing chord

cl             section lift coefficient

h             winglet height

CDp        profile drag coefficient averaged over span

K             induced drag factor

S              plan form area

V             airspeed

VCC        average cross-country speed

VCR        crossover velocity

VS           sink rate

W            weight

ρ             air density

C_Amax         maximum cabin altitude

Introduction

Gliders, also known as plan to launch, are aircraft that are “powered during aircraft either by dynamic response of the air against their airfoils” (Wayback Machine, 2003). The goal of a glider is primarily for recreational flying for long periods of time; therefore it cannot require a motor to fly. However, many contemporary gliders are equipped with a retractable motor and/or rotors to consciousness and maintain flight. Whenever the engine is turned off, the self-launch maintains the same flying characteristics. There are two typical ways to launch gliders without the need for a performance exhaust (Wayback Machine, 2003).

Winglets have come a long way in the last 10 years, from being capable to do little more than increase overall glider performance to becoming so common that only some gliders currently leave the factory with wings. A amount of people worked together to understand better how winglets operate, create theoretical techniques for analyzing speed, and develop design approaches that enable the advantages to be tuned so that advances in pass performance may be realized in a variety of soaring situations. This is an intriguing case study in design process, wherein court case as well as mistake, theoretical model, as well as test flights all helped contribute towards the positive resolution of a hard question.

However the construction of an elevated powered aircraft to optimize average cross-country velocities in just about any particular weather scenario looks to be relatively straightforward when contrasted to certain other current aerial vehicles, it’s really quite hard. This is important for the reason that what a powered aircraft must have been able to ascend successfully in thermal underwear at slower revs while also gliding effectively among thermal underwear at incredible velocities while flying cross country. As a result, a good design must strike a balance between the competing demands of rising or cruising under a wide variety of soaring circumstances.

The aircraft’s ability to circle and maneuver with the low sink rates in thermal underwear that can fluctuate considerably in intensity, size, & form from week to week, and sometimes even over the course of a single flight, is required for effective ascent. The decrease of generated drag is a crucial concern throughout the design process since this necessitates turning flights at low speed and higher lifts ratios. Obviously, the much more easy technique to decrease generated drag is to employ broad spans, despite the fact that this might penalize efficiency in cruising aircraft.

Gliders vary in a variety of forms and sizes, but the essential design elements among most gliders remain the same. Most gliders follow the aerodynamics theories that allow them to fly. Whenever air rushes and over wings of something like a glider, the wings provide lift, which helps the glider to stay airborne. Gliders wing are made to create the most lift with both the least amount of drag.

Aims and Objectives

The project’s ultimate goal is to use NASA open VSP & XFLR-5 software to create a design concept for high-performance race gliders in a specific class and assess its aerodynamic characteristics. This has to be backed up by research and comparisons to other models.

The following are some of the objectives and outcomes which must be met.  

• 2D concept design model
• Cross – sectional view of winglet
• 3D concept design model
• Ability to comprehend & assess
• Lift, drag, glide ratio, and ability to achieve altitude – aerodynamic characteristics of something like the ultimate race glider design

Literature review

The research study will look at the many type’s aircraft racing gliders up in a particular class & compare them to one another based on aerodynamic qualities.

The chosen design & class is used as a foundation for developing a close to the edge glider with software.

If gliders are always descending, how then do gliders stay airborne for minutes?  

The explanation is that they have been built to be extremely efficient and to drop gradually. The glider can really gain height if the pilot can find a bubble of wind rising faster than aircraft is lowering, boosting its energy stored. The term “updraft” refers to pockets of upper troposphere. When a breeze flying at a slope and mountain needs to ascend to climb out over, updrafts form over darker land areas that receive heat from sunlight, air currents can sometimes be observed. The warmth from the earth heats the air around it, causing it to rise. Thermals were raising pockets containing warm air. Huge gliding raptors like owls and hawk were frequently spotted circling within a thermal to acquire height without beating their wing. Aircrafts behave in the same way.

Its Space Shuttle stays in space due to orbital physics related towards its speed, not because of lift from its wings. Earth is almost devoid of air. The wings cannot create lift if there is no air present. (Gliders,2021).Any plane, gliders or otherwise, may fly or glides outside of a motor as much as it maintains a consistent speed as well as a reasonable rate. However, it will progressively lose height throughout this process, and indeed the rate at which it loses altitude will be determined by its own weight, aerodynamic, as well as other physical considerations. Gliders are built to take maximum use of the forces that are required to glide. They’re composed of light material with weight placed at strategic spots to allow for better air flow. The wing is indeed engineered to provide more lift while reducing aerodynamic drag, resulting in the best glide ratio. Glide ratio is the ratio of miles covered to elevation lost. For instance, the Cessna 172 has a 9:1 glide ratio.

When there is no way to increase height, a high glide ration is recommended since the distance covered is higher. A glide ratio of somewhere between 40:1 & 70:1 can be achieved. (The most thorough description of how gliders fly without power, 2021)  The three aspects that govern the evolution of gliders are aerodynamic, construction methods, and flying tactics. The results of this advancement may be seen in the flight performances.

Lift drag ratio of E = 30 was found with 15 m wing spread (regular class) and E = 36 with 20 m wing spread (open class) using standard profile (e.g. Goettingen & NACA fourth- and 5th profile) as well as standard building (wooden with cover). The surface loading with thono machines were close to m/S 20 kg/m2, resulting in modest minimum sinking speeds and poor glide performance in high-speed flights.

A significant performance boost was gained with the construction of laminar profiles that display low drag in vast ca-ranges, — in other words broad turbulent low depressions. E = 41 for standard class glider and E = 57 for gliders of the open class are currently at their apex. Nevertheless, the dimension precision & surface integrity of something like the wings required to meet rigorous standards in order for these designs to be used successfully.

The needed dimensional accuracy of the model for low structural weights might be accomplished by using the material GFK (fiberglass reinforcing plastic) in combination with both the negatives construction mode. Let us note that fs 24 “Phoenix” of something like the University Flying Group Stuttgart, the very first GFK glider through the use of a laminar profile, that flew in 1957 and also had a remarkable lift drag ratio of E = 40 for just a 16-meter wing span.

Because laminar profiles have low drag, lots of high friction coefficient, it must have been able to raise aspect ratios and area loading using the G•FK construction mode, this dramatically increased glider efficiency while still allowing for decent ascension.

For surface loading of m/S = 30 kg/m2, aspect ratios of = 20 at 15 m & = 36 at 20 m wing spread are victorious.

The Academic Flight Team Brunswick’s SB 6 Rnd SB 7 and the BS 1 evolved from the SB 6, both of which flew for the first time in 1961/1962, are these out in the growth of advanced gliders.

The profile drag was minimized by using enough that curving flaps (trailing edge flaps): The curved flap location allowed for the tailoring of the shape towards the demands of slow & tall flying by relocating smaller, lesser laminar depressions. The influence of the bent flap here on drag polar in contrast to rigid profiles.

The use of curved flap profile is, however, confined to the unrestricted and FAI-15 m classes.

Until date, it has been demonstrated that cruising speed optimization is mostly attainable using mathematical models, but that adding new boundary conditions causes a shift inside the optimum.

I’d like to give some beginning constructive suggestions inside the subsequent subsections; no claims to completion are made.

A general potential for something like the L.5: enhancement of flying characteristics, irrespective of whether models, seems to be the decrease of drag for something like a certain specific flight & loaded mass (improvement of an existing glider) On only one hand, the profiles drag should be reduced, and then on the other, overall fuselage-, empennage-, & interfering drag should be reduced. Messer, Horsemen, & Quast will offer comprehensive talks on the decrease of profiles drag.

Various tests on fuselage prototypes (Horstmann,1977) indicate that by properly shaping for something like a consistent aircraft cross-sectional area, aircrafts savings of up to 25% can be expected as comparison to standard fuselages. Scientific Flying Groups are currently taking a very dramatic step in reducing drag. Because current stiff profiles can be developed without deterioration in quality in C_Amax for comparable drag as well as a constant centre of pressure distribution, the wingless gliders (all wing) idea, which had been abandoned for years, was resurrected.

If such a design can achieve pleasant flying characteristics, the tail-less glider might be a viable alternative to the current conventional gliders. Enhance positive can also be achieved by using profiles with broader laminar bouts of depression, even though these profiles have somewhat greater drags. Induced and damaging empennage drags can be reduced by increasing the aspect ratio. The above-mentioned gliders having winglets are good examples of this idea. Because of the larger lift-drag proportions, special attention must be paid to the circular flight qualities, because otherwise, the possibly apparent benefits cannot be used for flight, as previously stated. (Horstmann,1984)

These wings spread- & aspects ratio enhancements, which are exclusively allowed throughout the open course, provide an extra performance boost. The limitations of what may be done are determined mostly by the anno of it would do Laminar, but also by the in-wing spread, which is largely determined by flight qualities. In both circumstances, this results in a loss of agility as well as a deterioration of the features of stationary circular flight. I’d want to show how the circular flight characteristics – and hence as well the flight performance – may be enhanced using some of the findings of my computations for something like the lift-drag ratios distribution during circling flight.

Even though these findings do not add to our understanding of circle flight aerodynamics, they do provide the architect with the opportunity to make enhancements via particular procedures.

If the greatest feasible lift force is consistent during the wing spread, then wing seems far from c_max, other than at the circular pattern arm end:

The plain flight’s maximum speed is not attained; the stalling features particularly unpleasant (smearing).

One must ensure that perhaps the outer wing achieves the C_Amax first, which leads to greater use of the wing or otherwise reduced drag and better flying qualities, by using super-elliptical flap area dispersion throughout the outer wings and/or twisting alternatively, in my opinion, instead by correct profile. (Reichmann,1993)

Tumbling motions throughout wind storms (torn insulating layers), which make it extremely challenging to coordinate glider motions with rising air changes, are avoided if the form of the lift rise throughout the inner wing has no “danglers.” In circular flights, high aileron differentiations are beneficial. Depressive force differences, on the other hand, are feasible. Low distinction of something like the inner wing (curved flap) allows gliders to curved flaps to accomplish not only a nearly arbitrarily defined force slope, but also lower k-factors (more favorable lift distribution) and reduced or no could perhaps that otherwise would occur due to curvature loss for high distinctions. (Marsden,1991)

Project Planning

Tasks

• To guarantee that this project’s goal is fulfilled effectively, the tasks indicated and stated below should be done.
• Research and theory research/review
• Process glider foundation research to master basic principles
• Narrow research to specific class aircraft gliders & specify the specification by looking at numerous existing models and deciding which one is best.
• Create a data bank of the at minimum 4/5 gliders
• Propose your own glider design

– Glider design

– Winglets

– Aspect ratio

– Mass

– Diagrams

– Typical aerofoil

– Aerodynamic performance – lifts, drags, & glide ratio

– Creating a simulation & analyse the results – lift, drag, but instead glide ratio

Methodology

If the actions listed above are accomplished in the correct order, the project’s ultimate goal should be achieved. The goal of the literature review is to discover a few instances of extant racing glider aircraft. The chosen gliders should indeed be briefly explained and illustrated using drawings of something like the glider’s design from various angles, aerofoil geometry, and winglets. The specifications for each glider must always be defined inside the form of tables, with information including such wingspan, wing surface, aspect ratio, and load bearing capacity & empty weight, and performance data (lift, drag, speed).  This is to aid in determining and evaluating which gliders seems to be the finest, so that a high-performance race glider may be constructed using the best glider. A final version for something like the race gliders shall be properly designed and presented, then replicated using provided software and run through a model to acquire performance statistics. The task which will require the most effort is learning how and where to utilise software to construct a two and three dimensional model, since I will need to learn about using both. (Thomas, 1999)

Technical Discussion

The formation of span directed flow is one of the implications of providing lift on a limited wing. Temperature gradients induced by lower upper surface pressures compared to greater lower surface pressures cause inward spans wise flow upon that top surface & outwards span wise movement upon that lower surface.

The merger of those kinds of two flows with opposite directions at the trailing edge produces the vortices that are shed from a limited wing and are the source of induced drag. An endplate somewhere at end of something like a finite wing has been recognized since over a century to diminish span directed flow itself and reduce induced drag.

However, in order to be successful, the endplate should be so big that any decrease in drag is considerably outweighed by the rise in moistened area drag. Instead of being a basic fence that restricts span wise flow, a winglet bears an aerodynamic load that creates a flow allows interaction with the main wing, reducing span wise flow.

In essence, the winglet disperses or stretches these out tip vortex’s impact, reducing downwash and, like a result, generated drag. In this sense, the winglet functions similarly to an endplate for lowering span wise flow, and it does so with far less wetted surface since it carries the necessary aerodynamic stress. To put it another way, the winglet’s action is to cause vertical vortices diffusion at the tip area. (Yates, 1986)

Caused by mechanical speeds by the no planar elements of the winglet, this diffusion process manifests itself as an enlargement of the wake in the distant field. An upward winglet’s out of planes confined swirl creates vertical velocities inside the free wake, causing its wake field to spread span wise. When the efficiency is compared to the actual span, it can be higher than an ellipse loaded, simulating the impact of a time frame expansion. It should always be noted that, even while useful, a winglet pointed downward causes its wake to compress and is less effective in lowering generated drag than one positioned upward. The winglet’s profile drag component seems to be simpler than either the induced drag component. Any increase in wetted area will result in an increase in profile drag. As a result, adding winglets to an aircraft increases the wetted area and, as a result, the profile drags. Because the profiles drag coefficient stays generally constant whereas the drag rises with both the flow velocity, wing impact of something like the larger area is seen mostly at higher speeds. The extra wetted surface morphology penalty imposed by a winglet can be partially compensated by removing some of the existing wing tip while installing the winglet. But even though the reduced Reynolds number owing towards the smaller winglet chords would normally have somewhat bigger profile drag coefficients, the wide chords of the edge of the wing contrasted to the considerably smaller chords of the winglet give a major compensation in wetted area. In fixed-span classrooms, this drastically cutting of something like the tips is very beneficial. A winglet with a geometric inclination compared with fewer than 90 degrees keeps the whole span whether at the legal maximum or the minimum allowed. A winglet can be added in this fashion with much less change of wetted surface than if the original platform’s tip was simply expanded & rotated upward. The existence of winglets is also observed to enhance the quantity of laminar flow across the outer sections of the main wing.

When the tip is approached without winglets, the changeover line somewhat on top surface travels forward, but with winglets, an imposed advantageous pressure gradient leads it to shift aft.

As a result, winglets partially compensate for their greater wetted surface penalty by reducing profile drag across a portion of the leading edge of the wing. Simplest terms, the purpose of winglet design are to reduce induced drag as much as possible while increasing profile drag as little as possible. The profiles drag liability grows in severity as both the power coefficient lowers and indeed the velocity increases, whereas the generated drag advantage of winglets is highest at higher friction coefficient and lower flight speeds. The optimization of the winglet shape is complicated by the fact that the advantage & penalty are at various places in the flight regime. It becomes difficult, and it eventually necessitates inadequate methods of measuring the improvement in behaviors caused by winglets throughout the glider’s full flying envelope.

Winglet Geometry Issues

A lot of model parameters must always be taken into account while creating a winglet. The most significant aspects of setting the geometry are determining the airfoil type, chords dispersion, altitude, twist, sweeps, & toe angle. This design challenge is challenging since there are so many variables at play. The operating profile of a sailplane is further compounded by the fact that it blends a reduced, high-lift coefficients climbing phase with something like a high-speed, low-lift coefficients cruising phase, although both are approximately equal in significance. (Hoffstadt, 1977)

Airfoil Considerations

The purpose of both the winglet airfoil design, like most airfoil designs, is to provide the desired lift with both the least amount of drag. Inside the instance of something like the winglet airfoil, each winglet’s operating low-drag area should match the same for the wing. Similarly, the winglet really shouldn’t stop well before leading edge of the wing in relatively high flight. Each wing/winglet mixture has a unique connection between both the winglet lift force and the main wing lift coefficient, and ideally, each combo would have a specially designed winglet airfoil. In most circumstances, however, the tiny performance improvement that’d result is insufficient to justify quite an effort. It’s also worth noting that the data necessary to lead airfoil design is influenced either by winglet geometry, something that is influenced by the airfoil’s aerodynamic properties. As a result, the Winglet/airfoil construction process is an iterative, with the final product being the culmination of several multiple iterations. As a result, in additional to a precise airfoil design method, an imprecise way of estimating the influence of winglet design features on total sailplane performance is also required. The thin chords & consequent low Reynolds numbers make achieving the required design objectives for the winglet more challenging. This circumstance creates a trade-off between reducing the wetted area growth by utilizing tiny chords and the high profile drag coefficient that result from the low Reynolds numbers. The winglet’s narrow chords dictate an airfoil that performs well at Reynolds numbers ranging from 7.0×104 to 1.0×106. Separated flow bubble as well as the concomitant increases of profiles drag is a significant factor at these low levels. However, because the winglet should work across a smaller range in lift coefficients than a normal wing, this difficulty is mitigated to some extent. As a result, an airfoil built particularly for something like a winglet can still have lower drag than one developed for a tiny unmanned air aircraft, for example. Avoiding poor section performance with low flight velocity is an essential aim for the winglet airfoil design. Because the main benefit of something like a winglet is in climbing, stalling deploying winglet under these circumstances would almost surely result in performance degradation. As the airplane approaches stall, the section must create the highest lift coefficients needed by that of the winglet.Similarly, low-drag performance across the whole working range is critical, but it must be weighed against some other requirements. Excessive sectioning increases profile drag as velocity squared rises. At greater flying speeds, drag coefficients with low friction coefficient might have a significant influence on aircraft performance. The higher lift coefficient component of something like the airfoil drag polar is driven by this concept. The extent to which these factors impact performance is impossible to determine without examining the sailplane’s avionics suite. The quantity of gain required at low speeds to compensate for a deficit at high speeds necessitates a relatively exact technique of performance measurement. (Hoffstadt,1977)

Chord Distribution and Height

A number of competing variables influence the most appropriate winglet chord distribution. Above all, the winglet would have to be capable of creating the span wise pressure required to achieve a beneficial interaction with something like the main wing’s generated velocity field. Very short winglet chords need lift coefficients larger more than aircraft might provide at emphasis on low velocities. That, of turn, renders the winglet useless and might lead to extra drag as a result of the winglet’s ineffectiveness. The winglet has come to a halt. Overly big winglet chords, is from the other side, might result in poor performance.

The heavy stress on the winglet might overburden the main wing’s tip area, reducing platform effectiveness. This could also cause aircraft main wing’s outboard parts to stall early in severe situations.

To prevent this, each winglet would have to have been inadequately inefficiently, with both the wider chords just increasing the moistened surface increasing profiles drag.

This exchange is exacerbated even more by the desire for tiny chords to reduce the additional wetted surface while avoiding chords that result in excessive drag due to its relatively low Reynolds numbers. Even though it varies upon that airfoil, an adequate airfoil can function at low Reynolds numbers first before drag reduction owing to decreased area is compensated by the penalty due to a higher profile drag coefficient. For reality, at this breakeven threshold, reducing the Reynolds number leads the profiles drag coefficient approximately quadruple. In the vast majority of circumstances, the platform shape may be chosen without regard for the enhanced profiles drag coefficient caused by Reynolds number impacts. Although not quite as important, overall span wise chords dispersion are such that the load somewhat on winglet is almost elliptical as well as the resultant drag upon that winglet itself is reduced once the fundamental chord dimension has indeed been calculated. The winglet length is decided by that of the trade-off between both the generated drag advantage and the wetted area penalty that once chord dispersion has been defined.

Twist, Sweep, and Toe Angle

The winglet weight of the building can be further adjusted through span wise twisting & platform sweep following estimating the chords dispersion & height while consideration the needed loading, profile drag, & Reynolds number limits.

Increasing wash-in somewhere on the winglet has the same impact on load distribution as extending overall sweep.

As a result, if one variable, such as twist, is fixed as well as the sweep is customized to get the optimum performance, the situation is reduced. The designer’s primary issue was that more sweeping might generate cross-flow disturbances, causing its boundary layer too change sooner than it otherwise would have.

Even though there is little knowledge on this issue somewhere at Reynolds number (re) in question, it is recognized because as the Reynolds number lowers, the instability reduces.

As a result, assuming the winglet geometries have been confirmed in wind tunnel experiments, it is not really a concern as long as the sweep angles really aren’t more than 35 or 40 degrees.

The toe degree with which the winglet ought to be installed must be calculated once the foundation has already been defined.

The overall pressure on something like the winglet, including its incredible impact here on stress distribution of the main wing, is controlled by this angle.

Because the winglet’s angle of incidence is a consequence of something like the thawing lift coefficient, the toe angle choice will most likely only be genuinely ideal for one flying scenario.

Nonetheless, determining this angle in order to provide the highest potential performance over the full flight envelop is possibly the most important aspect of the construction process.

The Winglet Design Process

Past Methodologies

Penn State has experimented with a variety of winglet designs. Every one of these approaches has sought to quantify that balance between both the profile drag expense as well as the Induced drag advantage in some way. All previous efforts used what is known as that of the crossover point somewhat on sailplane speed polar prior to the current method. The airspeed beyond which the flight polar of the baseline aircraft and indeed the airplane with winglets overlap, and whether the percent increase in sink rate owing to the winglets is zero, correlates toward this position.

Winglets are advantageous underneath this speed; however they are harmful beyond this speed. Thus, the crossover point is the flight speed at which the benefit in induced drag due to winglets is equal to the profile drag penalty and occurs when

DPROFILE + DINDUCED = 0

This simple formula shows that by increasing the crossing line and then the more efficient the winglet are, the lower the generated drag may be lowered for an economy’s production in profile drag.

After applying a few reasonable assumptions and describing the overall drag change significantly with the increase of a winglet in words of something like the necessary parameters, the derivatives without respect to winglet height may be set to zero as well as the crossing speed, VCR, can indeed be accounted for.

In which the constant changes as even the wing let leading factors as well as the overall generated drag reduces as winglet altitude increases, h.

The higher the speed of the crossover point, higher lower overall profiles drag coefficient of something like the increased winglet area, CDp,WL, and that the larger the spanning loading.

The shape of something like the winglet may be used to influence the crossing point once it is understood.

For not only the ballasted or braced scenarios, the crossover point were selected to be greater than that of any expected cruising speeds throughout the early phases of adopting this basic principle.

Although predicated on a basic theory, the implementation of this equation produced in winglets which typically increased performance which was as excellent as the “Not quite so good” capacity to forecast changes in generated drag accordance with the changing in winglet shape.

HOW TO USE XLFR5

Concept Design

Figure 1 3D model in OpenVSP

Figure 2 VSP AERO

The airfoil shape must also be mentioned

Airfoil NACA 5210

Figure 3 CL vs. Wake Iteration

All the calculations must be presented in the report

Weight Estimate

Wing Sizing

The 0.5-meter width was chosen to overcome the problem of fitting the aircraft into the container constraints.

The 0.125 meter cord was chosen to keep the same aspect ratio as their initial model (2 meter wingspan). (Blackwell,1976)

This resulted in a 0.0625m2 area with a 4 aspect ratio. A next stage was to calculate a lift coefficient based on an expected flying velocity. The flying velocity was calculated using Equation:

K & cD, 0, the intrinsic drag coefficient, are indeed the unanswered questions throughout the equation below. Because that is a realistic assumption as with most aircrafts, the parasite drag coefficient was calculated to really be 0.07. The following equation was used to determine the variable K:

As with most aircraft, baseline Oswald tunable, e0, is commonly assumed to be about 0.9, providing a K= 0.088.

We seem to have been managed to get an 8 meter per second flight speed by combining this with the density of the air, overall weight, and wing size. With some of these factors in place, the following equation was used to calculate the lift coefficient:

The needed lift coefficient equals 0.89 if indeed the airplane glides somewhere at predicted flying speed. To make building easier, a parabolic dish airfoil were chosen, and everything offers enough force for with this airplane.

Sizing of tail

The tails may be sized once the wings shape and basic dimensions of something like the aircraft have been determined. We utilized equations from Raymer’s Modern Aircraft book to get the variables we needed to assess these equations, and we used historical data tables from Raymer to get the factors we needed. As presented in Section in Raymer for something like a sailplane, the tail plane volumes coefficient, cHT, and vertical stabilizer volume coefficient, cVT, was calculated to be 0.50 & 0.02 correspondingly. We thought that numbers for a sailplane would have been the most accurate estimate for the gliders. Somewhat on real aircraft, the azimuth and elevation tail length was determined. (Blackwell,1976)

Figure 4 Initial Tail Sizing

The equations used for sizing of the tails are:

These calculations produced a tail plane size of 149.7 cm2 as well as a tail size of 25.81 cm2. Simple geometric modification was used to obtain the size of the tailed surfaces from such areas.

Pitch Stability

The computation of two essential points is required to assess our aircraft’s stability during flying. The equivalent resistance, XNP, as well as the centre of mass, XCG, are all these. The gravitational centre is established by:

W stands for weight, while d stands for the length between the aircraft’s head as well as the ground. When one prototype simulation was built, these parameters were recorded. XCG= 12.5 cm again from bearing surface to use these data and formula 10. The neutral statement’s formula is:

When fixing the issue, XCG is made equal as XNP.

Inside the instance within this plane, S! Wing area = 0.0625m

S! Horizontal Tail Area = 0.0175m

𝜂 = 0.9

Solving for XCG gives a neutral point of XNP = 13.9 cm. With this data we used equation

13 to calculate the static margin:

𝑆𝑡𝑎𝑡𝑖𝑐𝑀𝑎𝑟𝑔𝑖𝑛 = 𝑋NP – 𝑋CG = XNP – XCG = XNP – XCG / C

X𝑐 = 𝑀𝑒𝑎𝑛 𝐴𝑒𝑟𝑜𝑑𝑦𝑛𝑎𝑚𝑖𝑐 𝐶h𝑜𝑟𝑑

Because the wing also isn’t tapering, the mean aerodynamic length is just the length of something like the wing.

This results in an 11.4 percent static profit.

The airplane is stable throughout flying because although the centre of gravity is front of the neutral position.

Simulation and Analysis

Type 2 (Fixed lift)

3D-Panels/VLM1

VInf = 46.449 m/s

Alpha = 10.50°

Mass = 0.000 kg

XCP = 0.720 m

YCP = 0.000 m

ZCP = 0.080 m

CL = 1.20664

CD = 0.05694

VCD = 0.00000

ICD = 0.05694

CX = 0.05694

CY = -0.00000

Cl = 0.00000

Cm = -0.44785

ICm = -0.44785

VCm = 0.00000

Cn = 0.00000

ICn = 0.00000

VCn = 0.00000

Figure 5 Wing calculation data at 11 degree

Figure 6 Plot

Figure 7 Cp of Wing

Figure 8 Plot of Cp

Discussions

And the calculations for how you figured out the measurement for the wing span, aspect ratio, chord length.

Conclusions

The high speed racing glider should have the tapered wings to get the maximum lift and lower drag. This glider max. Height is 8m to 10m with the wing area of 18m.

Bibliography

1983. Mueller. Design Study for a Glider with Wing Flaps. Thesis DFVLR Brunswick 1983.

Blackwell, J.A. Jr., “Numerical Method to Calculate the Induced Drag or Optimum Loading for Arbitrary Non-Planar Aircraft,” Vortex-Lattice Utilization, NASA SP-405, May 1976.

D.C. Terleth, L.M.M. Boermanso Preliminary Results of Windtunnel Measurements on Eight Sailplane Wing-Fuselage Combinations. Delft University of Technology 1981.

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