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Leading Edge Slot
A leading-edge slot is a fixed aerodynamic feature of the wing of some aircraft to reduce the stall speed and promote good low-speed handling qualities. A leading-edge slot is a spanwise gap in each wing, allowing air to flow from below the wing to its upper surface. In this manner they allow flight at higher angles of attack and thus reduce the stall speed. Purpose and development At an angle of attack above about 15° many airfoils enter the stall. Modification of such an airfoil with a fixed leading-edge slot can increase the stalling angle to between 22° and 25°.Clancy, L.J., ''Aerodynamics'', Section 6.9 Slots were first developed by Handley Page in 1919 and the first aircraft to fly with them was the experimental H.P.17, a modified Airco DH.9A. Their invention is credited jointly to Sir Frederick Handley Page and Gustav Lachmann. The first aircraft fitted with controllable slots was the Handley Page H.P.20. Licensing the design became one of Handley Page's major sou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leading Edge Slot
A leading-edge slot is a fixed aerodynamic feature of the wing of some aircraft to reduce the stall speed and promote good low-speed handling qualities. A leading-edge slot is a spanwise gap in each wing, allowing air to flow from below the wing to its upper surface. In this manner they allow flight at higher angles of attack and thus reduce the stall speed. Purpose and development At an angle of attack above about 15° many airfoils enter the stall. Modification of such an airfoil with a fixed leading-edge slot can increase the stalling angle to between 22° and 25°.Clancy, L.J., ''Aerodynamics'', Section 6.9 Slots were first developed by Handley Page in 1919 and the first aircraft to fly with them was the experimental H.P.17, a modified Airco DH.9A. Their invention is credited jointly to Sir Frederick Handley Page and Gustav Lachmann. The first aircraft fitted with controllable slots was the Handley Page H.P.20. Licensing the design became one of Handley Page's major sou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fieseler Fi156
The Fieseler Fi 156 ''Storch'' (, "stork") was a German liaison aircraft built by Fieseler before and during World War II. Production continued in other countries into the 1950s for the private market. It was notable for its excellent short field (STOL) performance and low stalling speed of 50 km/h (31 mph). French-built later variants often appear at air shows. Compared to most other liaison aircraft of the period, the ''Storch'' was quite large and heavy, with its wingspan exceeding 14 meters (nearly 47 feet) and its weight slightly over 1,300 kg (2,900 pounds) when fully loaded. It was significantly heavier, slower, and less agile than Allied liaison aircraft such as the American Piper L-4 or Stinson L-5, or the British Auster. Design and development Conception and production In 1935, the RLM (''Reichsluftfahrtministerium'', Reich Aviation Ministry) invited several aviation companies to submit design proposals that would compete for the production contract for a new ''Luft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dornier Do 27
The Dornier Do 27 is a German single-engine STOL utility aircraft that was designed and manufactured by Dornier GmbH (later DASA Dornier and Fairchild-Dornier). It was notable for being the first mass-produced aircraft in Germany following the end of the Second World War. The Do 27's precursor, the ''Do 25'', was developed by Dornier at the firm's facilities in Spain in order to satisfy a Spanish military requirement that called for a light utility aircraft with short takeoff and landing (STOL) performance. However, the Do 25 was not selected for production by Spain. Despite this, the aircraft was developed further to produce the Do 27, which was produced in quantity in both Spain and Germany. In addition to domestic sales, a large number of export customers, such as Portugal, emerged for the Do 27, and it had a lengthy service life with some examples still being used into the twenty-first century. The aircraft was appreciated for its relatively wide, comfortable cabin and exce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fieseler Storch
The Fieseler Fi 156 ''Storch'' (, "stork") was a German liaison aircraft built by Fieseler before and during World War II. Production continued in other countries into the 1950s for the private market. It was notable for its excellent short field (STOL) performance and low stalling speed of 50 km/h (31 mph). French-built later variants often appear at air shows. Compared to most other liaison aircraft of the period, the ''Storch'' was quite large and heavy, with its wingspan exceeding 14 meters (nearly 47 feet) and its weight slightly over 1,300 kg (2,900 pounds) when fully loaded. It was significantly heavier, slower, and less agile than Allied liaison aircraft such as the American Piper L-4 or Stinson L-5, or the British Auster. Design and development Conception and production In 1935, the RLM (''Reichsluftfahrtministerium'', Reich Aviation Ministry) invited several aviation companies to submit design proposals that would compete for the production contract for a new ''Luft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
STOL
A short takeoff and landing (STOL) aircraft is a conventional fixed-wing aircraft that has short runway requirements for takeoff and landing. Many STOL-designed aircraft also feature various arrangements for use on airstrips with harsh conditions (such as high altitude or ice). STOL aircraft, including those used in scheduled passenger airline operations, have also been operated from STOLport airfields which feature short runways. Design considerations Many fixed-wing STOL aircraft are bush planes, though some, like the de Havilland Canada Dash-7, are designed for use on prepared airstrips; likewise, many STOL aircraft are taildraggers, though there are exceptions like the PAC P-750 XSTOL, the Quest Kodiak, the de Havilland Canada DHC-6 Twin Otter and the Peterson 260SE. Autogyros also have STOL capability, needing a short ground roll to get airborne, but capable of a near-zero ground roll when landing. Runway length requirement is a function of the square of the minimum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boundary Layer Control
Boundary layer control refers to methods of controlling the behaviour of fluid flow boundary layers. It may be desirable to reduce flow separation on fast vehicles to reduce the size of the wake (streamlining), which may reduce drag. Boundary layer separation is generally undesirable in aircraft high lift coefficient systems and jet engine intakes. Laminar flow produces less skin friction than turbulent but a turbulent boundary layer transfers heat better. Turbulent boundary layers are more resistant to separation. The energy in a boundary layer may need to be increased to keep it attached to its surface. Fresh air can be introduced through slots or mixed in from above. The low momentum layer at the surface can be sucked away through a perforated surface or bled away when it is in a high pressure duct. It can be scooped off completely by a diverter or internal bleed ducting. Its energy can be increased above that of the free stream by introducing high velocity air. Nature Fra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mechanical Energy
In Outline of physical science, physical sciences, mechanical energy is the sum of potential energy and kinetic energy. The principle of conservation of mechanical energy states that if an isolated system is subject only to conservative forces, then the mechanical energy is constant. If an object moves in the opposite direction of a conservative net force, the potential energy will increase; and if the speed (not the velocity) of the object changes, the kinetic energy of the object also changes. In all real systems, however, nonconservative forces, such as frictional forces, will be present, but if they are of negligible Magnitude (mathematics), magnitude, the mechanical energy changes little and its conservation is a useful approximation. In elastic collisions, the kinetic energy is conserved, but in inelastic collisions some mechanical energy may be converted into thermal energy. The equivalence between lost mechanical energy and an increase in temperature was discovered by Jame ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viscosity
The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water. Viscosity quantifies the internal frictional force between adjacent layers of fluid that are in relative motion. For instance, when a viscous fluid is forced through a tube, it flows more quickly near the tube's axis than near its walls. Experiments show that some stress (such as a pressure difference between the two ends of the tube) is needed to sustain the flow. This is because a force is required to overcome the friction between the layers of the fluid which are in relative motion. For a tube with a constant rate of flow, the strength of the compensating force is proportional to the fluid's viscosity. In general, viscosity depends on a fluid's state, such as its temperature, pressure, and rate of deformation. However, the dependence on some of these properties is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drag (physics)
In fluid dynamics, drag (sometimes called air resistance, a type of friction, or fluid resistance, another type of friction or fluid friction) is a force acting opposite to the relative motion of any object moving with respect to a surrounding fluid. This can exist between two fluid layers (or surfaces) or between a fluid and a solid surface. Unlike other resistive forces, such as dry friction, which are nearly independent of velocity, the drag force depends on velocity. Drag force is proportional to the velocity for low-speed flow and the squared velocity for high speed flow, where the distinction between low and high speed is measured by the Reynolds number. Even though the ultimate cause of drag is viscous friction, turbulent drag is independent of viscosity. Drag forces always tend to decrease fluid velocity relative to the solid object in the fluid's path. Examples Examples of drag include the component of the net aerodynamic or hydrodynamic force acting opposite to the di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leading-edge Slat
Slats are aerodynamic surfaces on the leading edge of the wing of a fixed-wing aircraft which, when deployed, allow the wing to operate at a higher angle of attack. A higher coefficient of lift is produced as a result of angle of attack and speed, so by deploying slats an aircraft can fly at slower speeds, or take off and land in shorter distances. They are used during takeoff and landing or while performing low speed maneuvers which may take the aircraft close to a stall, they are retracted in normal flight to minimize drag. Slats are one high-lift device used on high speed turbojet aircraft, trailing edge flap systems running along the trailing edge of the wing are common on all aircraft. Types Types include: ;Automatic: The spring-loaded slat lies flush with the wing leading edge, held in place by the force of the air acting on them. As the aircraft slows down, the aerodynamic force is reduced and the springs extend the slats. Sometimes referred to as Handley-Page sla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fuel Consumption
A fuel is any material that can be made to react with other substances so that it releases energy as thermal energy or to be used for work. The concept was originally applied solely to those materials capable of releasing chemical energy but has since also been applied to other sources of heat energy, such as nuclear energy (via nuclear fission and nuclear fusion). The heat energy released by reactions of fuels can be converted into mechanical energy via a heat engine. Other times, the heat itself is valued for warmth, cooking, or industrial processes, as well as the illumination that accompanies combustion. Fuels are also used in the Cell (biology), cells of organisms in a process known as cellular respiration, where organic molecules are oxidized to release usable energy. Hydrocarbons and related organic molecules are by far the most common source of fuel used by humans, but other substances, including radioactive metals, are also utilized. Fuels are contrasted with other s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boundary Layer Separation
In fluid dynamics, flow separation or boundary layer separation is the detachment of a boundary layer from a surface into a wake. A boundary layer exists whenever there is relative movement between a fluid and a solid surface with viscous forces present in the layer of fluid close to the surface. The flow can be externally, around a body, or internally, in an enclosed passage. Boundary layers can be either laminar or turbulent. A reasonable assessment of whether the boundary layer will be laminar or turbulent can be made by calculating the Reynolds number of the local flow conditions. Separation occurs in flow that is slowing down, with pressure increasing, after passing the thickest part of a streamline body or passing through a widening passage, for example. Flowing against an increasing pressure is known as flowing in an adverse pressure gradient. The boundary layer separates when it has travelled far enough in an adverse pressure gradient that the speed of the boundary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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