1. IN THE NAME OF GOD

2. SUPERSONIC PLANESFluid Mechanics 2 Course Seminar - Teacher: Dr. Hoseinalipour - TAs: Mr. Zamani and Mr. Madadelahi - Presented by: Jahani and Abdolzade - Springe 2013 3. CONTENTSIntro History Introductions Theories and Equations Engine Applications 4. INTROA heavier-than-air machine that is kept aloft by the forces on its wings Common types of airplanes are airliners, large planes usually used to transport passengers; military planes; and general-aviation aircraft, which cover all airplanes that are not airliners or military aircraft An airplane is thrust forward by a propeller or other means of propulsion, such as a jet or rocket. Typical speeds for supersonic aircraft are greater than 750 mph but less than 1500 mph, and the Mach number M is greater than one and less than 3. Above Mach 5, the term hypersonic is used. 5. HISTORY Generals X-1 ConcordLeonardo da Vinci was the first man to attempt the scientific design of flying machines. But in his time no motor was available which was powerful enough to lift a person into the airThe first successful controlled airplane flight was made by the Wright brothers near Kitty Hawk, North Carolina, on December 17, 1903 The first of the X-planes. It was based on thetransport had an ogival delta wing, a The Concorde supersonic shape of a .22 caliber bullet, withfuselage and four underslung Rolls-Royce/Snecma Olympus slender revolutionary thin, straight wings. The rocket-powered Bell, X-1 only carried to a regular service have been 593 engines. the was SSTs to see height of about 12,200 meters under Tupolev Tu-144 Concorde and the the belly of a Boeing B-29 Superfortress before being released 6. INTRODUCTIONS The branch of physics dealingshockthe flow of air or loud noise created by the with wave set up by an other gas around a body in at supersonic speeds. aircraft or missile traveling motion relative to it. Aerodynamic forces of booms: N-waves and U-waves. The There are two types depend on the body's size, shape, and velocity; The on the density, compressibility, supersonic and interface that forms between a N-wave is generated from steady flight conditions, and its fluid and an obstacle, such as denser medium. viscosity, wave theory of airplaneletter "N.aacute angle pressure temperature, and pressure of the gas. In the is shaped like the wings, the Many examples are found in astronomy. A bow The U-wave, or focused boom, is generated from between the wing profile (roughly, measured shock forms at the outermost part of a planetary maneuvering flights, and its pressure wave is shaped like the along its bottom) and the wing's motion relative magnetosphere, where the high-speed flow of letter to the surrounding air. "U." the solar wind is suddenly slowed to subsonic speed by the planetary magnetic field The aspect ratio is the square of the wingspan divided by the platform area of the wing: AR = b2/S Mach number Forces of flight Aerodynamics Angle of attack Aspect ratio Bow shock Sonic boomIt is a measure of how long and slender a wing is from tip to tip 7. MACH NUMBERDescriptive of something the travels at A unit of speed, named after that Austrian speeds greater than Mach equal times the ambient physicist Ernst Mach, 5 (five to the ratio of the speed a sound). At such speeds, the speed of ofmoving object to the speed of sound temperature in medium under ambient in the surroundingthe boundary layer and on the surface conditions.of the moving vehicle exceeds 1,800F (1,000C) and aerodynamic heating becomes Flight in the range between the onset of compressibility effects in aircraft design. (around Mach number,0.8important and the establishment of fully M < M, of 0.7) subsonic The(around Mach number of 1.4). V-2 rocket was the first human-made object supersonic flight conditions 0.8 < M < 1.2 transonic to achieve hypersonic flight. In February 1949, its 1.2 < Mupper < 5.0 supersonic While the aircraft itself may bestage reached a maximum velocity of traveling less than the speed of M > 5.0 hypersonic 5,150 mph (8,288 km/h) speed of sound sound, the air going around the aircraft exceeds the more than five times at some locations on thethe speed ofthe regions where the local aircraft. In sound. At sea than the speed of sound, known as Mach airspeed is near or greaterlevel, the speed of sound, compressibility 1.0, and the air miles may vary because of effects are encounteredis about 761densityper hour (1,225 km/h). At 20,000 ft (6,096 m), the speed local shock waves, expansions, or flow choking. of sound is 660 mph (1,062 km/h). Subsonic Transonic Supersonic Hypersonic 8. FORCES1. (ROCKETRY). The forward force generated by a rocket. Thrust is produced by the expulsion of a Drag reaction mass, such as the hot gas products of a Thrust chemical reaction. F = mpve Lift 2. (AERODYNAMICS). Thrust is also one of the four forces of flight acting on an aircraft, the others being weight, drag, and lift. Thrust must be greater than drag to achieve the forward acceleration needed for takeoff The lifting force on a flying object (in and to increase an aircraft's speed in level flight. An particular, a wing or a whole aircraft), due to its aircraft flying at a constant speed will have thrust equal motion relative to the surrounding air. It must be to drag. equal to or greater than the weight of the object in flight and acting in the opposite direction. Lift can be increased by increasing the forward speed of the aircraft or by increasing the angle of attack 9. DRAG Theory Types CoefficientResistance to motion through a fluid. As applied Drag is generated by nine conditions associated through the to aircraft and spacecraft passing aerodynamics A dimensionless number used in with the motion atmosphere, it is the an aircraft. of the resultant of air particles over component to describe the drag of a shape. The drag There are several types of to relative airflow measured parallel to force due drag is independent of the size of the coefficient, Cd, form, pressure, skin direction of motion the object and is usually determined in a wind tunnel. friction, parasite, induced, and wave which are described below. Formequation used to calculate drag is: the The drag and pressure drag are virtually same type of drag. Form or pressure drag is D = V2SCD caused by the air that is flowing over the aircraft or airfoil. The separation of air creates turbulence and results in pockets of low and high pressure that leave a wake behind the airplane or airfoil 10. HYPERSONIC FLOW THEORIES Shock Layer Entropy Layer Viscous Interaction Temperature Combined EffectThis kind of shock wave is called an oblique shock because it forms at some angle to the the leading edge must be rounded or blunted in some way surface of manufacture and to ease heat (a shock wave perpendicular to both for practicality of wedgeproduces friction and fluxes. travel at high velocities Whenheat. Part of the kinetic thethe a anormalshocknear the a thisthe surface is edge, air, of the body's As travels through energy thin shock). Close tobodyblunt leadingknown as obliqueregion becomes Mach number "boundary layer" is the body surface called theincreases,thatcarried angle highlymotion isShock theory the air and shock formed. curved. absorbed by tells us the entropy increases away becomes smaller, as increase becomesfigure as illustrated"freestream" in the greater In this a shock,bodyslows down from the across layer, theand the entropyprocess called viscous from the air through a below. increases. at flow near velocity ofstrength Therefore,Sincedistance between the the shock the airflow to zero thethe surface. the nose passes dissipation. However, hypersonic vehicles create wedge shock decreases . The so much heatfactors driving this experiencelayer two nearly normalsuch high temperatures a much through a primary surface and thewill boundary thatwith and shock, it increasing in compared growth changeincrease cause chemical the fluid to occur greater arecan actually speed. they an in entropy viscosity ofto flow passing through changes and a decreasethe density. The result offurther factors is that the muchin fluid through which they fly from the body in shallower shock angle these boundary layer thickness varies as the square of the centerline Mach number: The classical boundary layer grows within this entropy layer and may be greatly affected by the entropy gradients. In Thus, as Mach number increases, the boundary layer can that addition, the entropy layer is a region of strong vorticity grow rapidly large gradients inhigh velocity flowfield near the can generate resulting in very the drag. surface, a phenomenon called "vorticity interaction." 11. ENGINE Turboprop engine Turbofan engine Ramjet Turbojet engineAn engine that works by expelling a fluid jet The first type of jet engine to be developed and backward so that the reaction to this exhaust one that, various jet engine remained as it Thepropels inpossible forms, hasinvolving,jet engine simplest vehicle forward. Both the in the widespread useparts. It day. The turbojet1913 was does, nothe rocketto this was types of reaction and moving engine are invented in byinvented by Frank Whittlerocket engine ramjet Ren Lorin in France.the in England is selfengine, but whereas Air entering the and, independently, the forwardOhain von movement is compressed and can by Hans a vacuum a in engine contained solely bywork in jet Germany. of the vehicle. can only function in the atmosphere.The principle by which all jet engines (and rockets) work is the third of Newton's laws of motions, namely that for every action (force in one direction) there is an equal and opposite reaction (force in the opposite direction) 12. APPLICATIONS Transportation MilitaryCommercial Transports: Hypersonic vehicles in general and waveriders in Cruise Missiles: Military Applications: particular havegreatest proponent of hypersonic Though developing a man-rated hypersonic Probably the long been touted as potential high-speed commercial transports United States vehicle like those described above the to replace the travel over the years has been will likely Concorde. Somework and enormous cost,indicated require decades of aerospace and 1960s military. Trends of the 1950s companies, airlines, and government and higher militaries aroundaircraft hadwill fly fasterofficials that military the world to likely have have proposed conceptsentering service 7fighters hypersonic cruise vehicles cruising at Machby to 12 to survive, so missiles for high-altitude capable of carrying passengershigh-speed York 2015. Most current conceptsMachfrom more were and bombers cruising at for 4 or New X-43 Hyper-X scramjet test aircraft to Tokyo in under Although the trend soon fizzled LoFlyte low-speed handling test vehicle missiles are simple cylinders with no relation to not uncommon. two hours. waveriders and military planners looked to maneuverability X-30 hypersonic scramjet SSTO concept the military has recently and stealth for survival, shown renewed interest in hypersonic flight Possible Aurora Mach XB-70 Valkyrie Mach 3 research aircraft 5 reconnaissance aircraft configuration 13. END 14. TRANSPORTATION Concorde fuel efficiency comparisonAircraft histories One of thework on SST designs started inthe Tu- ] Serious problems with Concorde and the midAircraft Concorde[] Boeing 747-400 144's operation was first high engineof supersonic 1950s, when the the generation noise and Supersonic vehicle speeds demand narrower wing levels, Engines Jet fighter design shifts entering service. engine with were significantly between fuselage associated aircraftsubject to greater stresses and designs, and arevery high jet velocities used Structural issues supersonic and subsonic aircraft. Jet engines, as a passenger miles/imperial during take-off, to even 17 more importantly which flying temperatures. This leads andaeroelasticity problems, 109 High costs class,communities near the fuel efficiency at gallon over can supply increased airport. SST flexing. require heavier structures to minimize unwantedengines supersonic speeds, even though their specific fuel Takeoff noise and sonic booms a fairly high strongerthrusttherefore heavier) need SSTs also require a much specific (and (net consumption is during at higher speeds. Because thrust/airflow) greater must be pressurized structure because their fuselagesupersonic cruise, to to a their speed over the ground is greater, this minimize than cross-sectional area and, greater differentialenginesubsonic aircraft, which do not passenger miles/US 14 91 decreasenacelle drag. Unfortunately this implies thereby, in efficiency is less than proportional to gallon operate at the high altitudes necessary for supersonic a speed until well above Mach 2,the engines noisy high jet velocity, which makes and the flight. These factors together meant that the empty consumption per mile isparticularly at low which of Concorde is lower. weight per seatcauses problems more than three times that speeds/altitudes litres/passenger 16.6 3.1 of a Boeing 747. 100 km and at take-offTupolev Tu-144LL