The Speed of Supersonic Aircraft - Essay Example

AERODYNAMICS OF SUPERSONIC AIRCRAFT STUDENT NAME INSTITUTION NAME DATE OF SUBMISSION AERODYNAMICS OF SUPERSONIC AIRCRAFT Introduction Supersonic aircraft is a type of plane which can fly at speeds which are much greater than that of their sound. This are planes which fly at extremely high speeds of approximately 667 knots which are about the speed of sound. The aerodynamics of the supersonic planes is the analysis of the role played by the surface area and design of the aircraft in the development of various speed levels. The fluid flow around the aircraft is part of the analysis that is discussed in the study of the aerodynamics of the supersonic aircraft. The fluid flow around the wings of the aircraft is much dependent of the shape and the streamline of the object. This is a result of the assumption that fluids are incompressible hence an object can be passed through it without facing a lot of resistance depending on the body streamline (Yoshida, et al., 2015) When an a plane is moving through the air or any fluid, the molecules which are located immediately on the surface of the plane are disturbed by the motion of the plane. The resistance offered by the fluid is largely dependent on the ratio of the speed of the aircraft and the speed of sound in air. A parameter to measure this ratio was named after a great physicist and engineer, Ernest Mach. The speed ratio is referred to as Mach. This parameter is used to determine if the plane is referred to as supersonic, hypersonic, transonic. Supersonic aircraft are planes which fly with a Mach greater than that of sound. The relationship is shown below. 1< M < 3 Where M is the march ratio for supersonic aircraft. According to Kuchemann, (2014) Supersonic flights were initially manufactured for military use but after some time it was commercialized, but the idea did not succeed in the commercial market between 1970 and 2000. The planes are typically used by the military during a time of combat and transportation. Concord was developed to be used to transport passengers and other commercial uses. Most common examples of supersonic aircraft are the fighter jets; they are designed to cruise at speeds of about 750 mph to 1500 mph. The first aircraft to fly supersonically was the Bell X-1A, which was developed in 1947. This was a plane which practically proved that humans were able to fly supersonically. Shock waves are encountered by supersonic flights. This is experienced when a supersonic flight encounters the compressibility effects of air, and the density of air variation is causing shock wave and flow choking. Shock waves occur at cases when the speed of supersonic aircraft is equal to the speed of sound. V = C Where; V is the source speed C is the speed of sound The waves which are piled to a great amplitudes creating a sound barrier that opposes the motion of the supersonic aircraft. This is also referred to as sonic boom, which occurs when the buildup of unusual high amplitude waves forms behind the aircraft producing a sonic sound. This was experienced first by fighter jets’ pilots during the world war two. The pilots realized that during high-speed dives of speed ranging near the speed of sound cause an irregular increase in the flight speed. At this irregular speeds, the plane experiences an enormous increase in aerodynamic drag which was incomparable to normal speed increases as cited in Ashley, (2012). However, the supersonic aircraft also experienced reduced lift and maneuverability. This was marked by many pilots as the barrier behind flying at speeds higher than that of sound. The speed of supersonic flights was able to go past the speed of sound after some time. This is due to the ability of wave fronts lagging behind aircraft in a cone shaped manner and the source at the vertex. The shockwave is experienced after this, and the plane continuous to fly at high speed since the wavelength of the shock wave is reduced (Heath, et al, 2015). When the shock wave reaches a point where its speed is equal to the normal speed, it is eliminated and turned into the normal sound wave. V > C C speed of sound V speeds of flight The above relationship explains the occurrence and the fate of shock wave. This is a point which the speed of flight id higher than that of sound. The sonic barrier is eliminated and the plane continuous to fly at higher speeds. A sonic boom is produced when the flight is immediately exceeding the speed of sound. At this transition point, a wave is generated which affect the whole streamline of the plane. They initially caused a lot of accident due to the shock experienced by the pilot and the panic led to the disability of the pilot to control the plane due to the instability caused by the wave. The ratio of sound speed and flight speed is named after Ernest Mach. M = V / C Where M is the Mach ratio. This ratio is a dimensionless measurement of speeds in aerodynamics. The Mach 0.6 speeds slightly above the speed of sound and Mach 2 is speed which is twice the speed of sound. Subsonic Speeds are those who are ranging between zero and one. Planes with speeds higher than Mach one are referred to as supersonic speeds hence the term supersonic aircraft. The plane with speed equaling to the speed of sound are normally referred to as transonic. Those speeds are usually harmful to the plane and the pilot. However, this is experienced for a short time since the aircraft is destabilized for a short period and finally resumes normal speed. The wave is cone shaped which is composed of spherical wave fronts which overlap (El Din, et al. 2013). The wave fronts are propagated in a radial direction out of the cone shaped wavefronts. The speed which is acquired is vertical to the speed of the plane; the two displacements from two motions which are used in the determination of Mach angle which is important in the generation of thrust caused by the shock wave. The angle is affected by the orientation of the plane and hence the instability caused by the sonic boom. The plane can be overturned when there is an occurrence of the sonic boom while it is at a tilted angle greater than sixty degrees. When a plane is used for commercial purposes and the passengers are on board, the occurrences of sonic boom have been associated with many biological failures affecting the people aboard the plane. Shocks are related to many complexities due to the response by any individual. Sonic Shocks were related to the failure of Concorde, which was used as a commercial plane. This has led to the termination of services of Concorde in the commercial sector until recent development is promising the comeback in the commercial market. Wing design of supersonic aircraft The design of the wings of an aircraft plays a major role in its aerodynamics. The design which is much streamline is of greater advantage in the forwards thrust of a plane. The design of the aircraft wing has evolved over a period of time. The shape, size and even the materials used have been evolving over time. this are some of the factors that affect the motion of an aircraft while flying in space. The lift that is developed by an aircraft will entirely depend on the design which the aerofoil is designed. When wings are designed they have to consider the following; Type of aircraft that will be attached to it The altitude of operation The weight of the load it’s to carry The amount of fuel to be stored in the plane The speed of the plane The supersonic aircraft will have to consider mostly the speed since it’s the key component as to why it is referred to as supersonic. For a plane to move faster in space it as to develop very thin and effective foil which are streamlined. This is important since the resistance of air to the motion of the plane play a key role in the speed developed by the plane. Supersonic aircraft have thin and streamline foil design that is very efficient in reducing the resistance between the plane motion and the air motion. The altitude of operation is also important in designing a wing of a particular plane since at high altitudes there is the high resistance to motion. When the plane is designed with wide wings, it will be able to maneuver well at such altitudes and most likely being able to move at high speeds. Supersonic aircraft needs a particular wing to be attached to it and hence the need to develop specific requirements. The wings used by a supersonic flight should be very light for it to gain greater lift and hence moving very fast. The lightness of the plane wings is very important in developing maneuverability of the plane. Supersonic jets used by the military have very light wings which are important while in combat since the plane can turn swiftly to avoid attacks and destroy the enemy. In the development of wing design, the plane luggage has to be considered since the plane cannot be expected to travel at high speeds while carrying large luggage. The design of the wings will determine the amount of load that is to be transported by the plane. The wing designed also affect the amount of fuel to be stored since most storage spaces are designed on the plane wings. The following are some of the wings that are designed to various suite needs on an aircraft (Pines, 2012). Rectangular wings This are normally referred to as Hershey Bar, which is used for general purposes. It can carry a large amount of load and fly at relatively high speeds. It is normally used in the design of developing private planes which are used for general purposes to suit the owner. They are normally inexpensive to manufacture and maintain. This are not used in supersonic planes since speed level reached does not attain the classification of supersonic aircraft. See figure in the appendix. Swept wing This are wings which are designed for jets which travel at supersonic speeds. However, it requires a relatively large forward speed to gain the lift unlike in the rectangular wings. This type of wing produces a small amount of drag to the plane during motion. The wings also are very efficient at high altitudes. These wings are normally efficient in supersonic flights. Delta wing This is an advanced concept in wing design whereby the aircraft pulls back some of its wings to effectively create minimum drag. This can ensure that the plane travels at extremely high speeds which are experienced only in supersonic aircraft. It was used in the design of commercial passengers like the Russian TU-144 and BOAC’s Concorde. The wing design also has to affect the engine of the plane. The plane with light foil has a relatively small power engine. The engine which is constructed for the purpose of supersonic flights are much powerful and are light to be able to be used with the appropriate wings. The engine sound also plays a role in the type of plane to be constructed. Some engines are very noisy such that they are not used for commercial purposes. The supersonic aircraft use thrust gas turbine engines in their propulsion system. This is the type of engine which produces great thrust when an airplane is flying. The control of the plane also depends on the engine of the plane. When the plane needs to travel at an increased speed, then it has to be able to control the intake of fuel and to be able to fly at certain altitude. The plane has to contain an engine which can supply sufficient amount of thrust to the body of the plane. The number of engines will depend on the wing design and size since the engines are built on the wings (Donovan, 2015). When the plane has more than two engines, it is considered to be a massive aircraft. Most jets do not apply their engines on the wings but at the back of the plane. Supersonic jets have swept wings to allow control of the plane speed by the pilot. The wings allow the plane to vary the amount of drag it experiences. This control is unique in supersonic flights. Commercial flights that have been developed with supersonic speeds have been faced out due to several challenges experienced by the plane. According to Huda, & Edi, (2013), The Concord was faced out when a fatal accident occurred and was related to the supersonic speed. There are other supersonic planes like the Russian TU-144 and BOAC’s Concorde. Conclusion Supersonic aircraft are planes which can fly at speeds greater than those of sound. The aerodynamics of the supersonic planes depends on the wing design, the size of the plane the design of the plane and the use of the plane. The supersonic commercial plane was developed in the 1970s but failed due to the accidents which were fatal and the cost of manufacture and operation were not profitable. The supersonic speeds are related to the shock waves encountered when the plane fly at speeds equal to that of sound. The wave is caused by the piling up of conical waves on the surface of the plane wings. Swift Wing design has been implemented mostly in the supersonic aircraft. Bibliography Kuchemann, D. (2014). Aircraft shapes and their aerodynamics for flight at supersonic speeds. Advances in Aeronautical Sciences, 3, 221-252. Yoshida, K., Matsushima, K., Ueda, Y., & Ishikawa, H. (2015). U.S. Patent No. 9,031,817. Washington, DC: U.S. Patent and Trademark Office. Heath, C. M., Gray, J. S., Park, M. A., Nielsen, E. J., & Carlson, J. R. (2015). Aerodynamic Shape Optimization of a Dual-Stream Supersonic Plug Nozzle. Ashley, H. (2012). Piston theory-a new aerodynamic tool for the aeroelastician. Journal of the Aeronautical Sciences. El Din, I. S., Le Pape, M. C., Minelli, A., Grenon, R., & Carrier, G. (2013, June). Impact of multipole matching resolution on supersonic aircraft sonic boom assessment. In Progress in Flight Physics (Vol. 5, pp. 601-620). EDP Sciences. Pines, S. (2012). Aerodynamic flutter derivatives for a flexible wing with supersonic and subsonic edges. Journal of the Aeronautical Sciences. Donovan, A. F. (Ed.). (2015). Aerodynamic components of aircraft at high speeds. Princeton University Press. Huda, Z., & Edi, P. (2013). Materials selection in design of structures and engines of supersonic aircrafts: a review. Materials & Design, 46, 552-560. Appendix rectangular wing design swift wing design delta wing design Concorde Read More