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24-515: Development of the CitationJet was prompted by the 1985 discontinuation of the Citation I , a reaction to the increasing price of its Pratt & Whitney JT15D-1 engines, which rendered it uncompetitive with its larger straight wing Citation stablemates. Cessna believed that a substantial market still existed for a light 4-5 passenger jet with low operating costs, docile flying qualities, and

48-462: A pressurized cabin . The jet uses the Citation II's forward fuselage, a new carry-through section, a new laminar flow , supercritical wing developed with NASA and Boeing , and a T-tail . Powered by two 1,900 lbf (8.5 kN) Williams FJ44s , the 10,000 lb (4,500 kg) aircraft has a trailing link undercarriage for smooth landings, and can be flown by a single pilot. Range

72-464: A demand for 1,000 aircraft over ten years. Its first flight was on April 29, 1991, a Federal Aviation Administration (FAA) type certificate was awarded on October 16, 1992, and first delivery happened on March 30, 1993. The aircraft met its initial design goal: its normal cruise speed was 29 kn (33 mph; 54 km/h) faster than that of the Citation I, and the newer CitationJet outperformed

96-399: A large fairing encases the low wing center section, and the engines are mounted high on the tail. Composite materials save weight in non-load-bearing components including fairings and the nose radome . The cockpit features EFIS avionics; fuselage length is reduced 11 inches (27 cm) compared to the Citation I, and cabin length is reduced by 1 ft 6 in (46 cm), but with

120-434: A lowered center aisle for increased cabin height. The cockpit side windows are slightly smaller than those on earlier Citations to lessen interior temperature differences between the cockpit and the main cabin. Wing structure is a conventional ladder with chord-wise ribs over front and rear spars, and an aft sub spar to support the landing gear. The NASA high-speed 0213 airfoil sustains natural laminar flow over 30% of

144-530: A new, lighter airframe design would be needed, using less expensive and lower-thrust engines. To better compete with newer jets, Cessna also wanted to eliminate the step in the center aisle of the earlier Citations, created by the spar passing through the cabin. Cessna launched the $ 2.4 million (equivalent to $ 5.9 million in 2023) model 525 CitationJet at the October 1989 NBAA convention in Atlanta, estimating

168-595: A novel design feature to reduce weight: rather than conventional thrust reversers , the aircraft are equipped with thrust attenuator paddles that pivot from the rear fuselage, similar to those used on the Cessna T-37 Tweet military trainer. The ICAO aircraft type designator for the CJ2 models is C25A. The ICAO aircraft type designator for the CJ3 models is C25B. The ICAO aircraft type designator for

192-406: Is 1,500 nmi (2,800 km) with four passengers and it can cruise at 437 kn (503 mph; 809 km/h). The CitationJet retains the 58 in (147 cm) inside diameter, circular fuselage cross-section of the Citation I and II, a semi-monocoque construction of conventional aluminum alloys assembled with rivets , fasteners and adhesive bonding . To reduce interference drag ,

216-413: Is a very thin sheet of air lying over the surface of the wing (and all other surfaces of the aircraft). Because air has viscosity , this layer of air tends to adhere to the wing. As the wing moves forward through the air, the boundary layer at first flows smoothly over the streamlined shape of the airfoil . Here, the flow is laminar and the boundary layer is a laminar layer. Prandtl applied the concept of

240-412: Is characterized by eddies or small packets of fluid particles, which result in lateral mixing. In non-scientific terms, laminar flow is smooth , while turbulent flow is rough . The type of flow occurring in a fluid in a channel is important in fluid-dynamics problems and subsequently affects heat and mass transfer in fluid systems. The dimensionless Reynolds number is an important parameter in

264-427: Is in the smooth flow of a viscous liquid through a tube or pipe. In that case, the velocity of flow varies from zero at the walls to a maximum along the cross-sectional centre of the vessel. The flow profile of laminar flow in a tube can be calculated by dividing the flow into thin cylindrical elements and applying the viscous force to them. Another example is the flow of air over an aircraft wing . The boundary layer

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288-412: Is the property of fluid particles in fluid dynamics to follow smooth paths in layers, with each layer moving smoothly past the adjacent layers with little or no mixing. At low velocities, the fluid tends to flow without lateral mixing, and adjacent layers slide past one another smoothly. There are no cross-currents perpendicular to the direction of flow, nor eddies or swirls of fluids. In laminar flow,

312-643: The CJ4 models is C25C. Related development Aircraft of comparable role, configuration, and era Related lists Citation I Too Many Requests If you report this error to the Wikimedia System Administrators, please include the details below. Request from 172.68.168.237 via cp1104 cp1104, Varnish XID 211486050 Upstream caches: cp1104 int Error: 429, Too Many Requests at Thu, 28 Nov 2024 07:42:50 GMT Laminar flow Laminar flow ( / ˈ l æ m ɪ n ər / )

336-481: The Reynolds number increases, such as by increasing the flow rate of the fluid, the flow will transition from laminar to turbulent flow at a specific range of Reynolds numbers, the laminar–turbulent transition range depending on small disturbance levels in the fluid or imperfections in the flow system. If the Reynolds number is very small, much less than 1, then the fluid will exhibit Stokes , or creeping, flow, where

360-547: The ability to operate from short runways usable by twin piston -engined light aircraft , a formula that had made the Citation I successful. However, that aircraft had been stigmatized for its slower cruise speed than its competitors, which had progressively been addressed in the Citation S/II and Bravo and the Citation V, Ultra and Encore , but at the cost of operating economy. To offer increased speed with reduced purchase and operating costs, Cessna engineers realized that

384-401: The equations that describe whether fully developed flow conditions lead to laminar or turbulent flow. The Reynolds number is the ratio of the inertial force to the shearing force of the fluid: how fast the fluid is moving relative to how viscous it is, irrespective of the scale of the fluid system. Laminar flow generally occurs when the fluid is moving slowly or the fluid is very viscous. As

408-459: The fluid: laminar flow or turbulent flow . Laminar flow occurs at lower velocities, below a threshold at which the flow becomes turbulent. The threshold velocity is determined by a dimensionless parameter characterizing the flow called the Reynolds number , which also depends on the viscosity and density of the fluid and dimensions of the channel. Turbulent flow is a less orderly flow regime that

432-404: The laminar boundary layer to airfoils in 1904. An everyday example is the slow, smooth and optically transparent flow of shallow water over a smooth barrier. When water leaves a tap without an aerator with little force, it first exhibits laminar flow, but as acceleration by the force of gravity immediately sets in, the Reynolds number of the flow increases with speed, and the laminar flow of

456-429: The motion of the particles of the fluid is very orderly with particles close to a solid surface moving in straight lines parallel to that surface. Laminar flow is a flow regime characterized by high momentum diffusion and low momentum convection . When a fluid is flowing through a closed channel such as a pipe or between two flat plates, either of two types of flow may occur depending on the velocity and viscosity of

480-435: The older Citation I in all other significant metrics except maximum payload and approach noise, despite having 600 lbf (2.7 kN) less total engine thrust. Twenty years after its first flight, 1,450 CJs had been produced. As of June 2017, 2,000 of all variants had been delivered, with five million hours flown. The six-seat CitationJet is a monoplane with a cantilever wing , a retractable tricycle landing gear and

504-593: The transition range is typically between 1,800 and 2,100. For fluid systems occurring on external surfaces, such as flow past objects suspended in the fluid, other definitions for Reynolds numbers can be used to predict the type of flow around the object. The particle Reynolds number Re p would be used for particle suspended in flowing fluids, for example. As with flow in pipes, laminar flow typically occurs with lower Reynolds numbers, while turbulent flow and related phenomena, such as vortex shedding , occur with higher Reynolds numbers. A common application of laminar flow

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528-433: The upper surface for 10-15% better lift-to-drag ratio than the larger NACA 23000 -series wing of the Citation I. To maintain the wing's laminar-flow qualities and reduce weight, icing protection is provided by ducted bleed air rather than the deicing boots or fluid deicing systems used on earlier Citations. Its FJ44 engine has a 16:1 overall pressure ratio and a 2.58:1 bypass ratio . Early CitationJet models have

552-435: The viscous forces of the fluid dominate the inertial forces. The specific calculation of the Reynolds number, and the values where laminar flow occurs, will depend on the geometry of the flow system and flow pattern. The common example is flow through a pipe , where the Reynolds number is defined as where: For such systems, laminar flow occurs when the Reynolds number is below a critical value of approximately 2,040, though

576-504: The water downstream from the tap can transition to turbulent flow. Optical transparency is then reduced or lost entirely. Laminar airflow is used to separate volumes of air, or prevent airborne contaminants from entering an area. Laminar flow hoods are used to exclude contaminants from sensitive processes in science, electronics and medicine. Air curtains are frequently used in commercial settings to keep heated or refrigerated air from passing through doorways. A laminar flow reactor (LFR)

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