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Leading Edge Slot
A leading-edge slot is a fixed aerodynamics, aerodynamic feature of the wing of some aircraft to reduce the Stall (flight), 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 angle of attack, 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 (flight), 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fieseler Fi156
The Fieseler Fi 156 ''Storch'' (, "stork") is a liaison aircraft designed and produced by the German aircraft manufacturer Fieseler. Its nickname of ''Stork, Storch'' was derived from the lengthy legs of its main landing gear, which gave the aircraft a similar appearance to that of the long-legged, big-winged bird. Developed during the mid 1930s in response to a request from the Reichsluftfahrtministerium (''Reich Aviation Ministry'' or RLM), the Fi 156 was an affordable and easy to construct aircraft purpose designed for the liaison, forward air control, army co-operation, and medical evacuation roles. On 24 May 1936, the Fi 156 V1 performed its maiden flight; the first deliveries took place less than a year later. It was well regarded for its excellent short field (STOL) performance and low stalling speed of 50 km/h (31 mph). Around 2,900 aircraft of various models, the most commonplace being the ''Fi 156C'', were produced between 1937 and 1945. The Fi 156 quickly became popula ... [...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 World War II, 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 STOL, 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, comfortab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fieseler Storch
The Fieseler Fi 156 ''Storch'' (, "stork") is a liaison aircraft designed and produced by the German aircraft manufacturer Fieseler. Its nickname of '' Storch'' was derived from the lengthy legs of its main landing gear, which gave the aircraft a similar appearance to that of the long-legged, big-winged bird. Developed during the mid 1930s in response to a request from the Reichsluftfahrtministerium (''Reich Aviation Ministry'' or RLM), the Fi 156 was an affordable and easy to construct aircraft purpose designed for the liaison, army co-operation, and medical evacuation roles. On 24 May 1936, the Fi 156 V1 performed its maiden flight; the first deliveries took place less than a year later. It was well regarded for its excellent short field (STOL) performance and low stalling speed of 50 km/h (31 mph). Around 2,900 aircraft of various models, the most commonplace being the ''Fi 156C'', were produced between 1937 and 1945. The Fi 156 quickly became popular on the export market, e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
STOL
A short takeoff and landing (STOL) aircraft is a fixed-wing aircraft that can takeoff/land on short runways. Many STOL-designed aircraft can operate on airstrips with harsh conditions (such as high altitude or ice). STOL aircraft, including those used in scheduled passenger airline operations, can be operated from STOLport airfields that feature short runways. Design STOL aircraft come in configurations such as bush planes, autogyros, and Conventional landing gear, taildraggers, and those such as the de Havilland Canada Dash-7 that are designed for use on conventional airstrips. The PAC P-750 XSTOL, the Daher Kodiak, the de Havilland Canada DHC-6 Twin Otter and the Wren 460 have STOL capability, needing a short ground roll to get airborne, but are capable of a near-zero ground roll when landing. For any plane, the required runway length is a function of the square of the stall speed (minimum flying speed), and much design effort is spent on minimizing this number. For take ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boundary Layer Control
In engineering, 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 a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mechanical Energy
In physical sciences, mechanical energy is the sum of macroscopic potential and kinetic energies. 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, 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 James Prescott Joule. Many devices are us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viscosity
Viscosity is a measure of a fluid's rate-dependent drag (physics), resistance to a change in shape or to movement of its neighboring portions relative to one another. For liquids, it corresponds to the informal concept of ''thickness''; for example, syrup has a higher viscosity than water. Viscosity is defined scientifically as a force multiplied by a time divided by an area. Thus its SI units are newton-seconds per metre squared, or pascal-seconds. Viscosity quantifies the internal friction, 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 center line than near its walls. Experiments show that some stress (physics), 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drag (physics)
In fluid dynamics, drag, sometimes referred to as fluid resistance, is a force acting opposite to the direction of motion of any object moving with respect to a surrounding fluid. This can exist between two fluid layers, two solid surfaces, or between a fluid and a solid surface. Drag forces tend to decrease fluid velocity relative to the solid object in the fluid's path. Unlike other resistive forces, drag force depends on velocity. Drag force is proportional to the relative velocity for low-speed flow and is proportional to the velocity squared for high-speed flow. This distinction between low and high-speed flow is measured by the Reynolds number. Drag is instantaneously related to vorticity dynamics through the Josephson-Anderson relation. Examples Examples of drag include: * Net force, Net Aerodynamic force, aerodynamic or Fluid dynamics, hydrodynamic force: Drag acting opposite to the direction of movement of a solid object such as cars, aircraft, and boat hulls. * Viscou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leading-edge Slat
A slat is an aerodynamic surface on the leading edge of the wing of a fixed-wing aircraft. When retracted, the slat lies flush with the rest of the wing. A slat is deployed by sliding forward, opening a slot between the wing and the slat. Air from below the slat flows through the slot and replaces the boundary layer that has travelled at high speed around the leading edge of the slat, losing a significant amount of its kinetic energy In physics, the kinetic energy of an object is the form of energy that it possesses due to its motion. In classical mechanics, the kinetic energy of a non-rotating object of mass ''m'' traveling at a speed ''v'' is \fracmv^2.Resnick, Rober ... due to skin friction drag. When deployed, slats allow the wings to operate at a higher angle of attack before stall (flight), stalling. With slats deployed an aircraft can fly at slower speeds, allowing it to take off and land in shorter distances. They are used during takeoff and landing and while perfor ... [...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 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 substances or de ... [...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 boundar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
