Unreferenced date December 2009 Aerodynamicdiameter is a physical property of a Particulate matter particle in a viscous fluid such as air . In general, particles have irregular shapes with actual geometric diameters that are difficult to measure. Aerodynamicdiameter is an expression of a particle s aerodynamic behavior as if it were a perfect sphere with unit density and diameter equal to the aerodynamicdiameter. Such a model has the same terminal settling velocity . Aerodynamicdiameter is commonly applied to particulate pollutants and inhaled drugs to predict where in the respiratory tract such particles will deposit. Calculations Drug particles for pulmonary delivery are typically characterized by aerodynamicdiameter rather than geometric diameter. The velocity at which the drug settles is proportional to the aerodynamicdiameter, d sub a sub . math d a d e frac rho p rho 0 chi frac 1 2 d s frac rho b rho 0 frac 1 2 math where math d e math equivalent volume diameter math d s math Stokes s equivalent diameter math rho 0 math standard particle density 1g cc . math rho p math particle material density math rho b math bulk material density less than math rho p math if porosity math chi math shape factor . For spherical species, 1. Aerodynamicdiameter is the diameter of a sphere of unit density 1g cc that has the same gravitational settling velocity as the particle in question. It s given as math d a d p frac rho p rho 0 frac 1 2 math DEFAULTSORT AerodynamicDiameter Category Aerodynamics Category Aerosol science Fluiddynamics stub nl Aerodynamische diameter ja sv Aerodynamisk diameter ... more details
about the notion of diameter in graph theory Distance graph theory the computer network protocol Diameter protocol Image CIRCLE 1.svg thumb right Diameter In geometry , a diameter of a circle is any straight .... The diameters are the longest chord geometry chords of the circle. The word diameter derives from ... metron , a measure ref http www.etymonline.com index.php?term diameter Online Etymology Dictionary ref . In more modern usage, the length of a diameter is also called the diameter . In this sense one speaks of the diameter rather than a diameter, because all diameters of a circle have the same length, this being twice the radius . For a convex set convex shape in the plane, the diameter is defined ... such as the Reuleaux triangle , the width and diameter are the same because all such pairs of parallel ... definitions given above are special cases of a more general definition. The diameter of a subset .... So, if A is the subset, the diameter is supremum sup d x , y x , y A . Some authors prefer ... ask a topologist 2004 task show msg msg 0860.0002 Re diameter of an empty set ref In differential geometry , the diameter is an important global Riemannian geometry Riemannian invariant mathematics invariant . In plane and coordinate geometry, a diameter of a conic section is any chord which passes ... Idiom Parlance parlance the diameter of a lesion is the longest line segment whose endpoints are within the lesion. Diameter symbol Image Sign diameter.png thumb 150px Sign Unicode from Autocad drawing ... variable for diameter, Unicode , is Homoglyph similar in size and design to , the Latin small ... 8 key press 9 key press 6 key press 0 on the numeric keypad . On an Apple, Inc. Apple Macintosh , the diameter ... with the command diameter which is part of the wasysym package. The diameter symbol Unicode & x2300 ...?id lxndiWaFMvMC&pg PA23 . ref See also Distance graph theory Graph or network diameter Angular diameter Hydraulic diameter Caliper , micrometer , tools for measuring diameters Eratosthenes , who ... more details
wiktionary aerodynamic Aerodynamics is the science of the motion of air. Aerodynamic may also refer to Aerodynamic song Aerodynamic , a song by Daft Punk Aerodynamic center See also Aerobraking Automotive aerodynamics disambiguation ... more details
Image levit.jpg 300px right thumb Aerodynamic levitation apparatus a spherical sample is floated on a gas stream which flows through the conical nozzle. Sample is heated by a CO sub 2 sub laser and temperature is measured from sample brightness by a pyrometer. File Schwebender Ball La Boom 16011999.jpg thumb Aerodynamic levitation of objects can be also a nice effect in party locations. Here a light ball flies in an air stream generated by a ventilator in the square box Aerodynamic levitation is the use of gas pressure to levitate materials so that they are no longer in physical contact with any container. In scientific experiments this removes contamination and nucleation issues associated with physical contact with a container. Overview The term aerodynamic levitation could be applied to many objects that use gas pressure to counter the force of gravity , and allow stable levitation . Helicopters and air hockey pucks are two good examples of objects that are aerodynamically levitated. However, more recently this term has also been associated with a scientific technique which uses a cone shaped nozzle allowing stable levitation of 1 3mm diameter spherical samples without the need for active control mechanisms. ref citation author Paul C. Nordine, J. K. Richard Weber, and Johan G. Abadie journal Pure and Applied Chemistry title Properties of high temperature melts using levitation year 2000 volume 72 pages 2127 2136 doi 10.1351 pac200072112127 issue 11 ref Aerodynamic levitation ... produced by Aerodynamic Levitation Since crystal nucleation is suppressed by levitation, and since it is not limited by sample conductivity unlike electromagnetic levitation , aerodynamic levitation ... O produced by aerodynamic levitation and laser heating bibcode 2006JPCM...18L.407S issue 32 ref Physical ... , viscosity , density , surface tension , specific heat capacity , In situ aerodynamic levitation ... reflist 2 DEFAULTSORT Aerodynamic Levitation Category Levitation Category Aerodynamics it Volo a punto ... more details
Image Aerodynamic park.jpg right Aerodynamic Park in Berlin Adlershof The Aerodynamic Park Aerodynamischer Park of the Humboldt University of Berlin Humboldt University in Adlershof Berlin Adlershof was once part of the German Johannisthal Air Field . Laboratories, motor test beds, wind tunnels and hangars, erected in the 20s and 30s, are historical landmarks of the Aerodynamic Park today. On the grassy areas of the park is the site specific art site specific sound art Air Borne Office of Integrative Art Stefan Kr skemper with the collaboration of Karlheinz Essl located, in a loose spatial relation to the monuments of the Deutsche Versuchsanstalt f r Luftfahrt German Experimental Institute for Aviation and the exceptional university buildings Architects Volker Staab with Alfred Nieuwenhuizen, Georg Augustin and Ute Frank, a.o. . The park is the green center of the Campus Berlin Adlershof. commons category Aerodynamic Park External links http www.air borne.info Air Borne Soundscape and history of the Aerodynamic Park German and English coord 52 25 57 N 13 31 45 E region DE BE type landmark source dewiki display title Category Buildings and structures in Berlin Category History of aviation Category Landmarks in Germany Berlin struct stub de Aerodynamischer Park ru ... more details
File Aerodynamic mudflap.jpg thumb Aerodynamic mudflap for semis and trailers File Aerodynamic Mudflaps on Truck.jpg thumb Aerodynamic mudflaps on a semi File Aerodynamicpickup.jpg thumb Aerodynamic mudflaps for pickups An aerodynamic mudflap is a vehicle mudflap that is aerodynamically engineered using shaping, louver s or ventilated slats to improve airflow, reduce sidespray and lower aerodynamic drag . Minimizing the truck or automobile drag coefficient translates directly into improved fuel efficiency . Supercomputing technology applied to the problem of semi trailer truck drag has helped to validate such aerodynamic improvements. ref http money.cnn.com 2009 02 19 technology fortt kenworth.fortune index.htm?postversion 2009021914 Tech Transformation Heavy duty Computing , CNN Money, February 19, 2009 ref Traditional solid truck mudflaps can increase drag, but a study by the University of Tennessee at Chattanooga Research UT Chattanooga SimCenter indicated slatted mudflaps can reduce drag more than 8 percent, making the truck s drag coefficient comparable to one without any mudflaps fitted. ref http www.utc.edu Research SimCenter truck research.php Computational Simulations of Airflows Related to Class 8 Trucks and Affecting Fuel Economy and Exhaust Emissions , utc.edu ref A further advantage of the design is the heat venting capacity of aerodynamically optimized mudflaps. The improved airflow, commonly engineered into high performance automobiles, ref http www.youtube.com watch?v PVN9cDM86SY Audi R8 Design and Aerodynamics , YouTube, January 20, 2007 ref promotes the quick release of otherwise re circulated water and air from the fenderwell while improving performance by cooling the tires and brakes. See also Mudflap Mudguard References Reflist Category Automotive accessories ... more details
Infobox single Name Aerodynamic Cover DaftPunk Aerodynamic.jpg Artist Daft Punk from Album Discovery Daft Punk album Discovery B side Digital Love , Aerodynamite Released March 28, 2001 Format Compact Disc CD , 12 inch single 12 Recorded Genre House music House Length 3 27 Label Virgin Records Virgin Writer Thomas Bangalter br Guy Manuel de Homem Christo Producer Daft Punk Certification Last single One More Time Daft Punk song One More Time br 2000 This single Aerodynamic br 2001 Next single Digital ... AerodynamicAerodynamic is an instrumental track by Daft Punk featuring a prominent guitar solo. The track ... Online . Retrieved on August 7, 2007. ref This is reflected in the structure of Aerodynamic , which ... solos on Aerodynamic are in bad taste, but for us, it s all about being true to ourselves ... magazine Dazed & Confused volume 2, issue 92 December 2010 . ref The Aerodynamic single contained a B side remix titled Aerodynamite . Another remix of Aerodynamic features Detroit based hip hop music ... Club . The album also contains a longer remix of Aerodynamic featuring elements of One More Time Daft ... 2007 . Aerodynamic was later sampled for the Wiley rapper Wiley song Summertime from the album See ... 21, 2008. ref Reception Aerodynamic hit the U.S. dance charts through club play as the B side to Digital Love . The song was used in the French film L Auberge espagnole . Aerodynamic was also performed ... Myleene Klass plays Daft Punks Aerodynamic on Pantene Pro V Commercial Bot generated title ref ... News Myleene is the new face of Pantene Bot generated title ref Single track listing Aerodynamic 3 34 Aerodynamite 7 48 References Reflist External links Discogs release name Aerodynamic id 4031 http ... daft punk Virgin Records Daft Punk official website Daft Punk DEFAULTSORT Aerodynamic Song Category Daft Punk songs Category 2001 singles es Aerodynamic canci n fr Aerodynamic it Aerodynamic pt Aerodynamic fi Aerodynamic ... more details
Image aeroforces.svg thumb Forces on an aerofoil. Aerodynamic force is exerted on a body by the air or some other gas in which the body is immersed, and is due to the relative motion between the body and the gas. aerodynamics Aerodynamic force arises from two causes ref Hurt, H.H.Jr. Aerodynamics for Naval Aviators . p.29 ref ref Clancy, L.J. Aerodynamics . Section 4.10 ref ref Massey, B.S. Mechanics of Fluids , section 10.8.2 ref br the Surface force force due to the pressure on the surface of the body, and the force due to viscosity , also known as skin friction . Pressure acts locally, perpendicular to the surface and shear acts locally parallel to the surface. the net aerodynamic force over the body is due to the pressure and shear integrated over the total exposed area of the body. ref Anderson,J.D.Jr Aircraft performance and design . Section 2.2 ref When an airfoil or a wing is moving relative to the air it generates an aerodynamic force , in a rearward direction at an angle with the direction of relative motion. This aerodynamic force is commonly resolved into two components ref Hurt, H.H.Jr. Aerodynamics for Naval Aviators . p.14 ref ref Clancy, L.J. Aerodynamics . Section 5.3 ref Drag force drag is the force component parallel to the direction of relative motion, Lift force lift is the force component perpendicular to the direction of relative motion. In addition to these two forces, the body may experience an aerodynamic moment also, the value of which depends on the point chosen for calculation. The force created by a propeller aircraft propeller or a jet engine is called thrust and it is also an aerodynamic force since it also acts on the surrounding air . The aerodynamic force on a powered airplane is commonly resolved into three components thrust, lift and drag. ref Hurt, H.H.Jr. Aerodynamics for Naval Aviators . Fig 2.20 ref ref Clancy, L.J. Aerodynamics ... weight . Note that weight is a body force , and it is not an aerodynamic force. See also Optical ... more details
Multiple issues one source May 2009 primary sources May 2009 orphan February 2009 AeroDynamic Aviation is a flight school at Reid Hillview Airport in San Jose, California . It was founded in 1960 by Amelia Reid as Amelia Reid Aviation and originally run out of the trunk of her 1959 Ford . Following Reid s death in 2001, the school continued operation under the ownership of one of her former students, Zdravko Podolski. The school offers flight and ground training for Sport Pilot , Private Pilot and Commercial Pilot certificates, Instrument rating , as well as conventional landing gear tailwheel endorsement, complex endorsement and aerobatics . It also rents airplanes. AeroDynamic Aviation s fleet includes Aeronca Champ 7ACs, Zlin Savage Cub, Evektor SportStar , Taylorcraft L2s, Citabria 7ECAs, Citabria 7KCABs, Super Decathlon , Cessna 170 and Cessna 172 172 s and Piper Arrow and Piper Warrior Warrior airplanes. The flight school s alumni include Rod Machado , Sean D. Tucker and Jason Dahl who was First Officer on the ill fated United Airlines Flight 93 United 93 flight on September 11, 2001 . External links http www.aerodynamicaviation.com AeroDynamic Aviation Category Aviation schools Aviation stub ... more details
Aerodynamic heating is the heating of a solid body produced by the passage of fluid such as air over a body such as a meteor , missile , or airplane . It is a form of forced convection in that the flow field is created by forces beyond those associated with the thermal processes. The heat transfer essentially occurs at the vehicle surface where aerodynamic viscous forces ensures that the flow is at zero speed relative to the body for a very thin layer of molecules at the surface. When fluid flow slows down its kinetic energy is converted to heat in high speed flows, tremendous energy is represented by the mean motion of the flow. As the flow is slowed to near zero speed, its temperature increases, the gradient in the speed in a direction normal to the surface allows small scale mass transport effects to dissipate the temperature in the outward direction and thus the temperature at the surface is less than the stagnation temperature the actual temperature is referred to as the recovery temperature . These viscous dissipative effects to neighboring sub layers make the boundary layer slow down via a non isentropic process. Heat then conducts into the surface material from the higher temperature air. The result is an increase in the temperature of the material and a loss of energy from the flow. The forced convection ensures that other material replenishes the gases that have cooled ... of both the recovery temperature and the mass flow rate of the flow. Aerodynamic heating is greatest ... versa with the net direction set by the relative temperature of each. Aerodynamic heating increases .... The heating effects are greatest at leading edge s. Aerodynamic heating is dealt with by the use of high ... of ablative material . Aircraft Aerodynamic heating is a concern for supersonic and hypersonic ... liquid cooling of the leading edge s usually the fuel en route to the engine . Reentry vehicles Aerodynamic ... s into a gas at high temperature. The act of sublimation absorbs the thermal energy from the aerodynamic ... more details
sin alpha math math C x C L sin alpha C d cos alpha math For A Force Acting Away at the Aerodynamic ... Aerodynamic Center Category Aerodynamics Category Geometric centers de Neutralpunkt Str mungslehre ... more details
In a straight flight, the Stabilizer aircraft tail of the airplane aligns the fuselage into the relative wind . However, in the beginning of a turn, when the Aileron ailerons are being applied in order to bank the airplane, the ailerons also cause an adverse yaw of the airplane. For example, if the airplane is Flight dynamics rolling clockwise from the pilot point of view , the airplane yaws to the left. It assumes a crab like attitude relative to the wind. This is called a Slip aerodynamic slip . The air is flowing crosswise over the fuselage. In order to correct this adverse slip, the pilot must apply rudder right rudder in this example . If the pilot applies too much rudder, the airplane will then slip to the other side. This is called a skid . The skid is more dangerous than the slip if the airplane is close to a Stall flight stall . In the slip, the raised wing &mdash the left one if the airplane is turning to the right &mdash will stall before the lowered one, and the airplane will reduce the bank angle, which prevents the stall. In the skid, the lowered wing will stall before the raised one, and the airplane will tight the turn, and the stall can develop to a Spin flight spin . At high altitudes, there is plenty of space to recovery. But during the final approach, when the airplane is close to the ground, this stall spin accident is usually fatal. Pilots will typically enter a skidding turn in the airfield traffic pattern on the turn from base leg to final approach, unconsciously using the rudder in an attempt to tighten the turn and avoid overshooting the runway centreline ref name SHIF John S. Denker, See How It Flies . http www.av8n.com how htm snaps.html sec skids ref . Deliberate skids are used in aerobatics and aerial warfare aerial combat . See also Slip aerodynamic References Reflist Category Aerodynamics Aviation stub de Schiebekurve ... more details
in this work is math underbrace D f D pr near field underbrace D i D w D v far field math See also Aerodynamic ..., Massachusetts, USA. DEFAULTSORT Aerodynamic Drag Category Aerodynamics Category Fluid dynamics Category ... more details
A diameter tape D tape is a form of dendrometer that consists of a cloth or metal tape that is mainly used to measure diameter at breast height DBH . DBH is measured at a fixed height of convert 4.5 ft cm above the ground, where it is most convenient to measure diameter . DBH is measured up high so to avoid measuring a tree s butt swell. Butt swell is where the base of the tree is unconventionally thicker than the rest of the tree. Height and diameter are used to determine the volume of a given tree measuring above the butt swell is required to provide the most accurate measurement. Diameter is easily measured because the tape is calibrated in units of 3.14 pi inches or centimeters. The tape is actually measuring the tree s circumference but since circumference and diameter are related by pi, the diameter can easily be obtained. The only problem with the diameter tape is that the measurements assume the tree s trunk cross sections are perfectly circular. Thus the diameter tape just gives ... Williams.2002. Comparison of three dendrometers in measuring diameter at breast height. Northern Journal of Applied Forestry 19 28 33. ref Precision diameter tapes are used for measuring the true diameters ... tools made of 1095 clock spring steel. ref name Precision Diameter Tapes cite web title http www.newmantools.com pi.htm url http www.newmantools.com pi.htm ref The precision diameter gages consist ... circumferential distance into diameter measurement so the observer can read the diameter directly from ... to 144 inches 3600 mm . ref name Precision Diameter Tapes Measuring diameter To calculate the diameter of a tree, the tape diameter side facing user is wrapped around the tree at convert 4.5 ft cm above ground. Where the number 0 aligns with the rest of the tape, this is the diameter of the tree. Image ... that the tape is perfectly level and that the tape is not kinked, so as not to skew the reading of the diameter See also Biltmore stick Timber cruise References references DEFAULTSORT Diameter Tape ... more details
wiktionary redirect Major diameter Short pages monitor This long comment was added to the page to prevent it being listed on Special Shortpages. It and the accompanying monitoring template were generated via Template Longcomment. Please do not remove the monitor template without removing the comment as well. DEFAULTSORT Major Diameter Category Metalworking terminology Category Article Feedback 5 ... more details
wiktionary redirect minor diameter Short pages monitor This long comment was added to the page to prevent it being listed on Special Shortpages. It and the accompanying monitoring template were generated via Template Longcomment. Please do not remove the monitor template without removing the comment as well. DEFAULTSORT Minor Diameter Category Metalworking terminology ... more details
Orphan date May 2011 The tactical diameter of a ship is the distance travelled on sea surface during a turning circle test with maximum rudder angle by the center of gravity of a ship taken perpendicular to the initial track followed at approach speed when the heading has changed by 180 The ratio of the tactical diameter divided by the ship s length between perpendicular s gives a dimentionless parameter which can be used to compare ships manoeuvrability. External links http ittc.sname.org new 20recomendations pdf 20Procedures 202008 7.5 04 02 01.pdf Category Marine engineering ... more details
Refimprove date September 2009 The angular diameter or apparent size of an object as seen from a given position is the visual diameter of the object measured as an angle. In the vision sciences it is called the visual angle . The visual diameter is the diameter of the Projection mathematics perspective ... diameter for an object that is seen under an angle. For a disk shaped object at a large distance ... Diagram for the formula of the angular diameter The angular diameter of an object can be calculated ... is the angular diameter, and math d math and math D math are the visual diameter of and the distance ... s. For a spherical object whose actual diameter equals math d mbox act math , the angular diameter ... use, the distinction between the visual diameter math d math and the actual diameter math ... Image Angular diameter.jpg thumb 300px right Angular diameter the angle subtended by an object In astronomy the sizes of objects in the sky are often given in terms of their angular diameter as seen ... is about 206265 arcseconds. Therefore, the angular diameter of an object with visual diameter d ... 0 538 73317 5 ref math delta math 206265 d D arcseconds. The angular diameter of Earth s orbit around the Sun, from a distance of one parsec , is 2 two arcseconds . The angular diameter of the Sun, from a distance of one light year , is 0.03 , and that of the Earth 0.0003 . The angular diameter 0.03 of the Sun given above is approximately the same as that of a person at a distance of the diameter ... as seen from the Earth class wikitable Celestial body Angular diameter align left Relative size 10 ... File Comparison angular diameter solar system.svg thumb 300px Comparison of angular diameter of the Sun ..., view it from 10.3 m away. The table shows that the angular diameter of Sun, when seen from Earth is approximately ... diameter of the Sun is about 250,000 that of Sirius it has twice the diameter and the distance ... diameter ratio of 100,000, so Sirius is roughly 6 times as bright per unit solid angle . The angular ... more details
IPstack Diameter is an AAA protocol authentication, authorization and accounting protocol for computer networks, and an alternative to RADIUS . Diameter Applications extend the base protocol by adding ... . Comparison with RADIUS The name is a pun on the RADIUS protocol, which is the predecessor a diameter is twice the radius . Diameter is not directly backward compatibility backwards compatible , but provides ... ietf radext radsec Transport Layer Security for RADIUS Transition support for RADIUS , although Diameter ... boundaries Basic support for user sessions and accounting Applications A Diameter Application is not a Application software software application , but a AAA protocol protocol based on the Diameter base .... Examples of Diameter applications Diameter Mobile IPv4 Application MobileIP, RFC 4004 Diameter Network Access Server Application NASREQ, RFC 4005 Diameter Extensible Authentication Protocol Application RFC 4072 Diameter Credit Control Application DCCA, RFC 4006 Diameter Session Initiation ... Subscriber Server HSS and the Subscriber Location Function SLF communicate using the Diameter protocol. Generic Bootstrapping Architecture Bootstrapping Server Function History The Diameter protocol ... well with remote access, IP mobility and policy control. The Diameter protocol defines a policy protocol ... policies for many services. ref cite web url http tools.ietf.org html draft calhoun diameter framework 09 title DIAMETER Framework Document publisher IETF author Pat R. Calhoun, Glen Zorn and Ping Pan date 2001 02 accessdate 2009 04 30 ref Like RADIUS, Diameter provides AAA functionality, but in addition ... Datagram Protocol UDP . The Diameter protocol is further enhanced by the development of the 3rd ... are supported by Diameter applications. ref cite web url http blogs.sun.com naman entry introduction to diameter protocol title Introduction to Diameter Protocol What is Diameter Protocol? publisher ... Expand section date June 2008 The Diameter base protocol is defined by RFC 3588, and defines the minimum ... more details
The hydraulic diameter, D sub H sub , is a commonly used term when handling Fluid dynamics flow in noncircular tubes and channels. Using this term one can calculate many things in the same way as for a circle round tube. Definition math D H frac 4A P math where A is the Cross section geometry cross sectional area and P is the wetted perimeter of the cross section. For a round tube, this checks as math D H frac 4 frac pi D 2 4 pi D D math The Manning formula contains a quantity called the hydraulic radius . Despite what the name may suggest, the hydraulic diameter is not twice the hydraulic radius, but four times. For an Annulus mathematics annulus the hydraulic diameter is math D H frac 4 cdot 0.25 pi D o 2 D i 2 pi D o D i D o D i math and for a rectangular duct, if completely filled with fluid math D H frac 4 L W 2 L W frac 2LW L W math And for a rectangular duct, if partly filled with fluid math D H frac 4 L W 2L W math For the special case of a square duct, where L W , then D sub H sub L . For the other limiting case of a very wide duct, i.e. a slot of width W where L W , then D sub H sub 2 W . For a fully filled duct or pipe whose cross section is a regular polygon , the hydraulic diameter is equivalent to the diameter of a circle inscribed within the wetted perimeter . Hydraulic diameter is mainly used for calculations involving turbulent flow . secondary flow Secondary flows can be observed in non circular ducts as a result of turbulent shear stress in the turbulent flow. These secondary flows force the fluid into the corners of the pipe. When the flow is Laminar flow laminar , secondary flows do not occur, and therefore the entire cross section of the pipe is not filled. This will result in errors in calculations. Hydraulic diameter is also used in calculation of heat transfer in internal flow problems. See also Equivalent spherical diameter Hydraulic radius Darcy friction factor External links Category Fluid dynamics Category Heat transfer cs Hydraulick polom r ... more details
In science , the equivalent spherical diameter or ESD of an irregularly shaped object is the diameter of a sphere of equivalent volume ref Jennings, B. R. and Parslow, K. 1988 Particle Size Measurement The Equivalent Spherical Diameter. Proceedings of the Royal Society of London. Series A 419 , 137 149 ref . According to the IUPAC definition ref http www.iupac.org goldbook E02191.pdf Definition of equivalent diameter in the IUPAC goldbook ref , the equivalent diameter of a non spherical particle is equal to a diameter of a spherical particle that exhibits identical property e.g., aerodynamic, hydrodynamic, optical, electrical to that of the investigated non spherical particle. For particles in non turbulent motion, the equivalent diameter is identical to the diameter encountered in the Stokes law . See also Hydraulic diameter Shape factor Stokes radius References references Category Measurement bs Ekvivalentni sferni dijametar ... more details
Infobox military unit unit name Aerodynamic and Propulsion Test Unit image Image APTU FaCET.jpg 300px caption FaCET Test in the APTU country United States branch US Air Force role Test Facility nickname APTU AEDC Aerodynamic and Propulsion Test Unit APTU is a blowdown hypersonic wind tunnel driven by a combustion air heater CAH . ref http www.arnold.af.mil news story.asp?id 123160209 ref The facility is owned by the United States Air Force and operated by Aerospace Testing Alliance . History The AEDC Aerodynamic and Propulsion Test Unit started out as a vitiated air heater VAH conducting over 275 experiments for the development of many different aerodynamic and aerothermal systems. Upgrades to the facility started in 2002 in order to provide ground test capability for supersonic and hypersonic systems up to flight speeds of Mach 8. Capabilities The facility was designed to provide ground based simulations of supersonic and hypersonic flight conditions. The combustion air heater can provide total pressures from 200 psia to 2,800 psia 13.6 atm to 190.5 atm and a total temperatures from 1,200 R to 4,700 R 667 K to 2,611 K . Five nozzles ranging from Mach 3.2 to Mach 7.1 are currently available. ref http www.arnold.af.mil shared media document AFD 080625 010.pdf ref See also Arnold Air Force Base Supersonic wind tunnel Scramjet References references External links http www.arnold.af.mil Arnold Engineering Development Center official DEFAULTSORT Aerodynamic and Propulsion Test Unit Category Wind tunnels ... more details
The term controlled aerodynamic instability phenomena was first used by Cristiano Augusto Trein ref http www.cristianotrein.com ref in the Nineteenth KKCNN Symposium on Civil Engineering ref Matsumoto, M. Trein, C. Ito, Y. Okubo, K. Matsumiya, H. Kim, G. Controlled Aerodynamic Instability Phenomena An Alternative Approach for Wind Power Generation Systems , The Nineteenth KKCNN Symposium on Civil Engineering, Japan, 2006., ref held in Kyoto Japan in 2006. The concept is based on the idea that aerodynamic instability phenomena, such as K rm n vortex street , Aeroelasticity Flutter flutter , galloping and Aeroelasticity Buffeting buffeting , can be driven into a controlled motion and be used to extract energy from the flow, becoming an alternative approach for wind power generation systems. Justification Nowadays, when a discussion is established around the theme wind power generation, what is promptly addressed is the image of a big wind turbine getting turned by the wind. However, some alternative approaches have already been proposed in the latter decades, showing that wind turbines are not the only possibility for the exploitation of the wind for power generation purposes. In 1977 Jeffery ref Jeffery, J Oscillating Aerofoil Project , Report from the Pocklington School Design Centre, West Green, Pocklington, York, England., 1977. ref experimented with an oscillating aerofoil system based on a vertically mounted pivoting wing which flapped in the wind. Farthing ref http www.econologica.org wingedmills.html ref discovered that this free flutter could automatically cease for high ..., robotist, kite engineer uses aero instabilities to gain wind power from kites. ref Controlled aerodynamic ... concerning these interactions and their dependencies, aiming the understanding of the aerodynamic phenomena ... those aerodynamic instabilities and by developing new features, it is possible to propose ways to stimulate ... Controlled Aerodynamic Instability Phenomena Category Aerodynamics Category Wind turbines ... more details
context date March 2009 Aerodynamic potential flow or panel codes are used to determine the velocity and subsequently the pressure distribution on an object. This may be a simple two dimensional object, such as a circle or wing or it may be a three dimensional vehicle. A series of sources and doublets are used to model the panels and wakes respectively. These codes may be valid at subsonic and supersonic speeds. History Early panel codes were developed in the late 1960s to early 1970s. Advanced panel codes, such as Panair developed by Boeing , were first introduced in the late 1970s, and gained popularity as computing speed increased. Over time, panel codes were replaced with higher order panel methods and subsequently CFD Computational Fluid Dynamics . However, panel codes are still used for preliminary aerodynamic analysis as the time required for an analysis run is significantly less due to a decreased number of elements. Assumptions These are the various assumptions that go into developing potential flow panel methods Inviscid math nabla 2 phi 0 math Incompressible math nabla cdot V 0 math Irrotational math nabla times V 0 math Steady math frac d dt 0 math However, the incompressible flow assumption may be removed from the potential flow derivation leaving Potential Flow inviscid, irrotational, steady math nabla 2 phi 0 math Derivation of Panel Method Solution to Potential Flow Problem From Small Disturbances math 1 M infty 2 phi xx phi yy phi zz 0 math subsonic From Divergence Theorem math iiint limits V left nabla cdot mathbf F right dV iint limits S mathbf F cdot mathbf n , dS math Let Velocity U be a twice continuously differentiable function in a region of volume V in space. This function is the stream function math phi math . Let P be a point in the volume V Let ... Domain Aerodynamic Software , A Panair Distribution Source, Ralph Carmichael http hdl.handle.net ... Methods For The Solution Of Problems In Aerodynamic Intereference , Ralph Carmichael, 1971 NASA ... more details
In fiber optics , the mode field diameter MFD is an expression of distribution of the irradiance , i.e. , the optical Power physics power per unit area, across the end face of a single Transverse mode mode fiber. For a Gaussian intensity i.e. power density, W m sup 2 sup distribution in a single mode optical fiber , the mode field physics field diameter is that at which the electric field electric and magnetic field strengths are reduced to 1 e of their maximum values, i.e., the diameter at which power density is reduced to 1 e sup 2 sup of the maximum power density, because the power density is Proportionality mathematics proportional to the square of the field strength . See also Beam diameter FS1037C Category Fiber optics ... more details
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