Winglet on Aircraft

Inspired from eagle's wings, winglets are applied on aircraft's wings. Same principle applies to eagles, winglets reduce wintip vortices, small wing vortex that formed at the wing tips due to air pressure difference. High pressure on the lower wing works its way up to the low pressure on the upper wing and curls around it. Having these vortices on the wings reduce flight efficiency and enhance drag. 

Winglets reduce drag and result in better cruising speed. Not only that, operators take advantage of this drag reduction by controlling cruising speed, reducing fuel consumption. In general, longer wings would generate better lift for aircrafts. However, longer wings would mean weight addition and it's not ideal. Installing winglets would result in same lifting force as longer wing would. The advantage is that wings with winglet would generate the same amount of lift force than ones with longer wings and without winglet. 

Winglets on aircraft reduce drag making flying more efficient. This include fuel saving up to 5% with carbon dioxide emission reduction up to 5%. The percentage may not be magnitude but 500,000 gallons of fuel is saved per airline per year just by adding winglets on aircraft's wings.

Reference

http://www.airspacemag.com/flight-today/how-things-work-winglets-2468375/
http://www.airspacemag.com/flight-today/how-things-work-winglets-2468375/

Reflection- Sathveer Roopah

The most interesting part of the subject was how the use of natural concepts found in nature could help us in developing necessary solutions which could solve for issues in developing new technology that can help the sustainability for human beings on this planet. The basics of using biomimicry to solve for human problems is a very suitable approach but still very controversial if the subject addressed cannot be executed with proper engineering tools and equipment’s. Hence making the best of the subject we have, the relation of mechanics to natural behaviors can be related and found a way to bring the technology together. In our case, the subject helped the team to learn more about the fascinating eagle and its wings. The eagle has a very large wing span that helps the big bird in fast flight for attacks and other maneuvers. Compared to the other birds eagles have separate feather tips at the end of the wings which allows the reduction of drag forces along the body. Hence by implementing the technology in modern aircrafts., the industry of aviation can help in reducing the overall usage of fuel consumption for planes as drag forces would be reduced Hence increasing the sustainability of the industry and remain a competitive part of the traveling industry. Also with bigger planes coming into play, this technology can be used to develop a sensible way of operating big aircrafts around several airports and reach out more passengers than before as the winglets can help in developing small wings for big planes.

The design of such product using the basics of eagle winglets can be very interesting in the way the product responds to the sustainability and reliability. Hence implementing such technology to the aircrafts, the cost saving is increased, less energy is used and less pollution occurs. The fact that natural resources of fuel is depleting rapidly, we should think outside the box to find new ways of reducing the dependency on fossil fuel by increasing efficiency on the aircraft itself. Hence it is advisable for the solution to be implemented and used based on its simplicity and low-cost production.

Based upon previous group studies carried out for other modules at the university, team work is always a better point of working out a project. Various ideas and different concepts/point of views can be found from the team as the brainstorming process goes on. Working as a team can help in having different point of views and help in generating new ideas that can be potentially lifesaving or revolutionary if the engineering tools and techniques are applied properly with a good team work. Moreover, working as a team, we can achieve completion of the project in time and thus with even distribution of tasks among the team members, learning is never ending process as knowledge is shared.

Reflection by Wen Yong Xiang

The most remarkable idea of biomimicry inspired by an eagle is the winglet of an aircraft. The features from the eagle’s wings have inspired aircraft companies to create winglets at the tip of the wings. This winglet reduces the formation of vortex created at the end of the wing. Therefore, it significantly reduces the drag force and this helps to increase the efficiency of the aircraft. As mentioned in the blog earlier, it could save tons of fuel in a long run and this eventually save cost and the environment.

The implementation of the winglet on the aircraft’s wings is patentable as it increases the efficiency and sustainability of the aircraft in the long run. As drag reduces, the energy required for the aircraft to fly up reduces as well. This will reduce the fuel consumption and therefore cutting down the operation cost. Currently, there are numerous designs available in the market but our design is easier to be manufactured than the rests because of the simplicity of the design.

The team consisted of 5 members including myself. The tasks were distributed evenly to all members. Therefore, each member has a specific and meaningful task to complete. Through this, this assignment is successfully completed within the due date. 

Conclusion

It has been concluded that addition of winglet on aircraft's wings would reduce drag and result in more efficient flight. It heavily reduced wingtip vortex which adds the drag coefficient. The inspiration of this genuine design came from one of the most fearsome predators in the animal kingdom - eagle. 

Danial's Reflection

The most interesting proposed used of biomimicry that was developed was the inspiration of eagles that significantly reduced drag on aircraft. Drag has always been an issue in vehicles, especially when it come to flying vehicle where efficient flight is important. Simple change of wing design, by adding winglet on wingtips, would drastically reduced air vortex, causing lesser drag. It may save around 1 or 2% of energy, but in terms of fuel saving, it could save up to thousand tons of fuel in a year per flight. This resulted in significant positive outlook. 

The design of the aircraft wingtip is patentable as it proved significant results in efficient flight and energy savings. Currently, there are many winglet designs that has been patent, each has its own distinctive feature with its uniqueness. 

Working as a team has made this project easier as more members are available to complete certain tasks. Huge project or assignment such as this can be easily broken down into smaller, easier and more meaningful tasks, which can be assigned by every member. The tasks can be easily be finished in this manner. 

Nazween's Reflection

The interesting part of an eagle is that it is able to control flight which enables the eagle to control the drag acted upon the wings. This happens when the eagle control the feathers angle and direction by contracting or relaxing the wings muscle which allows the air to pass through at different surface areas. By doing so, an eagle is able to be swift and dive down to capture prays. This is most probably the most interesting feature to be mimicked onto real life scale.

It has already been patented and applied on real life scale. This shows that there is a value or market for the design. It helps reduce drag and makes it more fuel efficient which is highly affordable compared to previous designs. Also, airline companies have been studying further on the length of the winglet of the aircraft that can be applied to current airplanes to reduce the drag.

Since its semester 8, everyone is busy with their own task and activities that everyone can ship in little by little to ensure that the blog is run smoothly. Without them, it would have been a burden to even handle all the researching and blog writing individually. Also, having more ideas and sharing them makes it easier to brainstorm and think of ideas.

Reversed Engineering Worksheet

Design Worksheet

The following figure is the varieties of winglet designs that are currently available in the market.

Figure 1

Method for induced drag calculation

Airbus A320 aircraft’s specifications are taken and the total drag of the aircraft is calculated using the following formula. 

Figure 2

Where;

Cf -Skin friction drag coefficient

F-Form factor

Q-Interference factor

Swet-Wetted area of the surface

Sref -Wing area

Rec = Reynolds number of the component

V = Velocity

l = component characteristics length

u = kinematic viscosity for that flight condition 

Figure 3 

e - Span efficiency or Ostwald’s efficiency factor

AR – Aspect ratio

Cl – Lift coefficient

Λ – Sweep angle

Take-off performance calculation

The take-off distance of an aircraft is the total distance covered by an aircraft to clear the obstruction of height about 35 ft.

Figure 4

The above figure represents the standard take-off velocities that should be maintained during the take-off. In this work, the motive is to find the parameters associated with the take-off performance of an aircraft. Airbus A320’s specification is taken for the calculation and the take-off field length provided for the aircraft is 1500m. There are three phases in the aircraft take-off mission such as Ground roll, Transition to climb and Climb. Normally, the ground roll, i.e. distance covered by the aircraft on the ground before climb, is calculated by resolving the forces horizontally and vertically. The approximation formula for the ground roll is given by,

Figure 5

W = 78000 kg, 

C_L,max = 2.1 (approximate)

T (during take-off) = 24494 kg

S = 123 sq.m(calculated from wing span)

g = 9.81 (acceleration due to gravity)

ρ = 1.225 kg/m³ (density ground level)

A320 is operated with two CFM56-B engines where the take-off thrust for each engine is 23,500lbs. The total drag “D” in the above formula is calculated after substituting the values obtained from specification table. The total drag reduction is calculated from the total induced drag reduction for different velocities. Further, this total drag calculated with winglets is substituted in the ground distance formula in order to obtain the new total weight (W_new). The simplified formula for the W_new is given by the following equation,

Figure 6 

The take-off weight value for the same take-off distance is calculated for different values of total drag.

CAD Modelling

CATIA V5 R18 tool is used to develop the templates of different winglets and tip devices. Each winglet has been defined by a user feature where the user could choose between the types of winglet and modify the parameters associated with respective winglet model. A detailed description of the winglet templates are discussed in the following section.

Blended Winglet Template

Blended winglet template has been modelled with two different sections namely blended base and blended vertical. Blended base is a shape design model where it forms the intersection at the main wing tip chord and continues as a smooth curve to avoid the interference drag. The leading edge of blended base is formed by the conic section which depends on sweep plane, two tangent lines and two points which lies on the same plane. Radius of the leading edge could be varied by a real parameter and also it depends on base height associated with height parameter. The other parameters controlling the blended base were base span, cant angle, sweep angle and tip chord length figure 1(c). Cant and Sweep angles are made with respect to the base span line and not from root chord of the base. 

The later section i.e. the skeleton model of blended vertical is created in dependent with the blended base.  The leading edge is made tangent with the base leading edge curve in order to obtain a smooth surface. Blended vertical is also associated with a set of parameters which are height and tip chord length figure 1(c). 

Vertical and horizontal reference area of the blended template model are calculated and given as an output parameter figure 1(c). The height parameter for both sections of blended template does not represent the vertical height but the length of respective lines. The exact vertical height for the blended template is given as an output parameter named “reference leading edge vertical” from which the reference area is calculated based on the root chord and tip chord of the respective section. Similarly, the horizontal span of entire blended section varies with the cant angle and also with base span length. The total projected span is calculated by measuring the length of projected leading edge line which shown as green dotted line in figure 1(a) and figure 1(b).   

Figure 7

Figure 8

 1. Do you think your product, building, or system would work if manufactured?

Yes, because the methods of designing were based on the literature reviews. The necessary calculations were conducted to apply the mathematical solutions into the design of the winglet. The design was drawn in the CAD software for better precision. Then, the CAD model will be simulated by using the computational fluid dynamic (CFD) software to get the required results. The CFD results will be compared to the experimental results. If all these methods were conducted carefully and accurately, the numerical results will be similar to the experimental results. The results obtained that meet the objective of the construction of winglet will definitely work in real case scenario if manufactured according to the design.

2. Do you think that you could raise funds to pay for manufacturing? How would you go about raising funds?

Yes, definitely.

·        Get sponsorships from the companies (technical or financial) that are related to the airplane industry.

·        Raise funds is to pitch the idea to the public through crowd funding website, PitchIn

.

3. Do you think that many engineers explore solutions from nature into their inventions?

Yes. In the past, Engineers had used concepts and inspirations from nature in their inventions. One of the example is the invention of Velcro that is based on nature. In this modern era, sustainability of the product is the main concern as more Engineers look into biomimicry to improve the current inventions today to adopt more sustainable traits for future generations to come.

Furthermore, biomimicry provides design techniques to optimize engineering products or systems. An example is the re-derivation of Murray’s law, this determines the ideal diameter of the blood vessels by providing equation for tube diameter.