Reader's response draft 2
The article “What is a ‘Raked’ Wingtip?”, written by Trifly (2018) discusses that the design of the 787 is groundbreaking. It is groundbreaking, as the wing engineers of the B787 did not follow the usual methods that designers had been using for the aeroplane’s wings. The wing engineers did something different from the typical formula. The “upswept wingtip, [that] had been working [very] effectively” was redesigned to a wing that sweeps to the back Onemonroe (2023). The main function of a wingtip is to reduce the drag caused by the physics, and nature of the pressure differences between the upper and lower portions of the wing. The greatest push factor for using a raked wingtip is its fuel efficiency. According to Kim (2015), the writer mentions that Boeing and NASA conducted wind tunnel tests together, to prove the theory that wing tips improved fuel efficiency. The results from the tests show that the raked wingtip had the greatest reduction, 5.5% in drag compared to the other wingtips, 3.5% to 4.5% for the winglet as tested. However Trifly (2018), suggests that this raked wingtip technology might not be all good. As this technology by Boeing is still new and takes up more space than conventional winglets, the writer suggests that only time can tell if raked wingtips are a good replacement for winglets.
Despite having some disadvantages, the raked wingtips of the Boeing 787 show how having an unconventional swept-back design might be beneficial, as it improves the performance of the aircraft through improving efficiency and is ideal for operators from the increased passenger comfort. (argument/hypothetical and then examples why it is better)
The raked wingtips of the Boeing 787 are beneficial as
the fuel efficiency of the aircraft is greatly improved through the use of raked wingtips.
Vortices that are generated by the wingtips from the airflow through the wings are undesirable.
This poses some issues when the aircraft is in flight, as it reduces the aircraft's efficiency and safety. It significantly impacts passengers, by increasing the noise in the cabin. contributing a huge part, almost half of the drag (40%) is generated from the wing decreasing lift (Zaccara 2022). This shows that wingtip vortices and induced drag have a linear relationship, wingtip vortices greatly increase as induced drag increases. With the raked wingtips, wingtip vortices are greatly reduced. When vortices are formed, the 787 raked wingtips are very useful as they are swept back. They successfully diminish the effects of the vortices flowing from the main wing, by channelling it away from the wing, thereby reducing drag. Lesser drag within the wing area means less fuel is burnt as the engine does not have to overcome the increased resistance from the drag. Thus, achieving a 20% better fuel efficiency and greater cost savings for the operator. According to Greenworldwide (2023), the Boeing 787 ranks second on the list of five of the most fuel-efficient airplanes in the world. The raked wingtips have an advantage over winglets during takeoff as they improve not only by reducing the drag on wings but increasing lift, both of which are important for takeoff.
https://nap.nationalacademies.org/read/11839/chapter/5#37 This is especially important and a huge contributing factor to achieving fuel efficiency. This is because the phases that the aircraft consumes the most fuel rate are taking off and the climbing stage to reach the cruising altitude (maybe can put how high).
Another reason why operators benefit from the raked wingtip is its passenger comfort.
Air that is flowing from the main wing to the wingtips is a crucial factor for drag to be generated (NASA Glenn Research Centre, 2023). With the help of the raked wingtips, drag is being reduced, through the increased wing span by the waked tips, allowing for a smoother flight as it has lesser turbulence.
The raked wings are also designed to bend more than conventional aircraft. While it may look frightening when it is bending, it has its advantages. Such as increasing on lift when the plane is stalling, which is a term used to describe when a plane is losing lift when the front portion of the wing is pointed too high up.
This increases passenger comfort as people who are more susceptible to motion sickness would not feel as much of an impact compared to other aircrafts. Especially on a long-haul flight, chances of experiencing turbulence are high and with the raked wingtips it reduces the effect.
The above-mentioned functions are crucially important factors for operators to decide whenever they are purchasing the aircraft. The 787 Dreamliner has lesser turbulent flights, and therefore making it at an advantage over aircrafts that have a conventionally designed wingtip.
However, the raked wingtips have some factors that might be worth considering. The design of the raked wing tips is in a swept-back configuration compared to the conventional upswept wingtip. It is therefore longer and makes manoeuvrability while taxiing or moving around an issue (Gudmundsson 2022). Upgrading of the airport taxiways and air gates from existing standards will be needed in order to be able to handle the 787.
Conclusion
Although the raked wingtips are a new technology, it had proven significant advantages for operators. Most notably, the president of Emirates, United Arab Emirates flag carrier, indicated that Boeing 787 is Emirates’ first option. According to Fehrm (2017), the 787 is the aircraft of choice for replacing their soon ageing Emirates fleets of Airbus A380s and Boeing 777s. Raked wingtips are also being introduced to newer planes such as the latest generations of Boeing 747s and 777xs, proving further the benefits of raked wingtips as they are crucial for saving fuel.
References
Fehrm. (2017, November 15). Why did Emirates choose Boeing’s 787-10? Leeham News and Analysis.
Gudmundsson (2022). General Aviation Aircraft Design: Applied Methods and Procedures (2nd ed.). Elsevier Science.
Guo (2021). Chinese Journal of Aeronautics. Chinese Society of Aeronautics and Astronautics.
https://www.sciencedirect.com/science/article/pii/S1000936121000480
Hepher (2024, May 22). Singapore airlines: What is aircraft turbulence and how common is it?| reuters. https://www.reuters.com/business/aerospace-defense/what-is-aircraft-turbulence-how-common-is-it-2024-05-21/#:~:text=Long%20planes%20can%20feel%20most,handling%20turbulence%2C%20according%20to%20Turbli.
Kim (2015). Numerical Analysis and Optimization of Wing-tip Designs. San Jose State University.
https://pdp.sjsu.edu/ae/docs/project-thesis/Uram.Kim-S15.pdf
Lyakhovetskaya, O. (2024, March 12). Top 5 most fuel-efficient airplanes in the world. Green Worldwide Shipping. https://www.greenworldwide.com/top-5-most-fuel-efficient-airplanes-in-the-world/#:~:text=The%20787%20Dreamliner%20is%20another,20%25%20better%20than%20comparable%20planes.
National Research Council. (2007). Assessment of Wingtip Modifications to Increase the Fuel Efficiency of Air Force Aircraft. The National Academies Press. https://nap.nationalacademies.org/read/11839/chapter/5#37
NASA Glenn Research Center. (2023, November 2). Winglets. NASA Glenn ResearchCenter
https://www1.grc.nasa.gov/beginners-guide-to-aeronautics/winglets/
Trifly. (2018, August 25). What is a “raked” wingtip? Essential Pilot. http://essentialpilot.co.za/2018/08/25/what-is-a-raked-wingtip/
Winglets vs raked wingtips: What’s the difference? Blog Monroe Aerospace. (2023, July). https://monroeaerospace.com/blog/winglets-vs-raked-wingtips-whats-the-difference/?srsltid=AfmBOorhHwjT5SD9-ztzPg32jJgiiQ5TIV4LQ1wWFWaSk6fHt191fuQx
Zaccara, M., Widnall, S. E. (2021, July 22). Flow control of wingtip vortices through Synthetic Jets.ScienceDirect
https://www.sciencedirect.com/science/article/pii/S0894177721001345.
Comments
Post a Comment