Lub luag haujlwm no tshwm sim hauv cov dav hlau vim muaj tis lossis lub cev nqa lub cev hloov pauv huab cua ua rau nqa, thiab hauv cov tsheb nrog cov tis airfoil uas hloov pauv huab cua ua rau muaj zog. Samuel Langley pom tias flatter, ntau dua nam piv daim hlau muaj ntau dua nqa thiab qis dua thiab tau qhia nyob rau hauv 1902. Yog tias tsis muaj kev tsim kho ntawm aerodynamic zoo ntawm lub dav hlau, kev tsim dav hlau niaj hnub yuav ua tsis tau.
Tag nrho aerodynamic quab yuam ua rau lub cev feem ntau suav hais tias muaj ob yam: nqa thiab hloov chaw. Los ntawm txhais tau tias, lub zog tivthaiv thaum uas tig mus rau lub txee ntws yog hu ua kev hloov chaw, thaum lub sij hawm qhov chaw ntawm lub txee ntws yog hu ua nqa.
Cov hauv paus ntawm aerodynamics yog qhov tseem ceeb rau kev tsom xam ntawm aerodynamic zoo ntawm tis. Kev nqa yog tsim los ntawm kev hloov cov kev taw qhia ntawm ntws ncig lub tis. Hloovkev taw qhia ua rau muaj kev hloov pauv hauv kev nrawm (txawm tias tsis muaj kev hloov pauv hauv kev nrawm, raws li pom nyob rau hauv cov lus tsa suab sib xws), uas yog acceleration. Yog li ntawd, txhawm rau hloov cov kev taw qhia ntawm kev ntws, ib lub zog yuav tsum tau siv rau cov kua dej. Qhov no tau pom meej meej ntawm txhua lub dav hlau, tsuas yog saib cov schematic sawv cev ntawm aerodynamic zoo ntawm An-2.
Tab sis tsis yog txhua yam yooj yim. Txuas ntxiv lub ntsiab lus ntawm aerodynamic zoo ntawm lub tis, nws yog ib qho tsim nyog sau cia tias qhov kev tsim ntawm huab cua nqa hauv qab nws yog nyob rau ntawm lub siab siab tshaj qhov cua siab saum nws. Ntawm lub finite span tis, qhov sib txawv siab no ua rau huab cua ntws los ntawm cov hauv paus hniav ntawm cov tis qis mus rau lub hauv paus ntawm nws sab sauv. Qhov kev ya dav hlau no ua ke nrog cov cua ntws los ua kom muaj kev hloov pauv hauv kev ceev thiab kev taw qhia uas twists lub airflow thiab tsim vortices raws ntug ntawm lub tis. Cov vortices tsim yog tsis ruaj khov, lawv sai sai ua ke los tsim tis vortices. Qhov tshwm sim vortices hloov qhov ceev thiab kev taw qhia ntawm airflow tom qab ntawm ntug ntug, deflecting nws downward thiab yog li ua rau ib tug nrov plig plawg tom qab tis. Los ntawm qhov kev xav no, piv txwv li, lub dav hlau MS-21 muaj qib siab ntawm nqa-rau-drag piv.
Air flow control
Lub vortexes tig hloov pauv huab cua nyob ib puag ncig tis, txo lub tis lub peev xwm los tsim nqa, yog li nws yuav tsum muaj lub kaum sab xis siab dua rau tib lub nqa, uas qaij tag nrho cov aerodynamic quab yuam rov qab thiab ua rau kom muaj zog ntawm cov khoom siv. tas zog. Angular sib txawv yog negligiblecuam tshuam nqa. Txawm li cas los xij, muaj qhov nce hauv kev sib npaug ntawm cov khoom nqa thiab lub kaum sab xis vim nws deviates. Txij li thaum deflection yog nws tus kheej lub luag haujlwm ntawm nqa, qhov ntxiv rub yog proportional rau lub kaum sab xis ntawm nce, uas tuaj yeem pom meej hauv A320's aerodynamics.
piv txwv keeb kwm
Ib daim duab plaub lub ntiaj teb tis tsim ntau lub vortex vibrations dua lub conical los yog elliptical tis, uas yog vim li cas ntau niaj hnub tis yog tapered los txhim kho nqa-rau-drag piv. Txawm li cas los xij, lub elliptical airframe yog qhov ua tau zoo dua li qhov kev cuam tshuam los ntawm kev ntxuav (thiab yog li lub kaum sab xis ntawm kev tawm tsam) yog qhov tsis tu ncua thoob plaws tag nrho cov tis. Vim muaj teeb meem kev tsim khoom, ob peb lub dav hlau muaj cov qauv no, cov piv txwv nto moo tshaj plaws yog Ntiaj Teb Tsov Rog II Spitfire thiab Thunderbolt. Tapered tis nrog ncaj coj thiab trailing npoo tuaj yeem mus txog qhov kev nqa nqa elliptical. Raws li txoj cai dav dav, cov tis ncaj, tsis muaj tis tsim 5% thiab cov tis tapered tsim 1-2% ntau induced luag tshaj li lub tis elliptical. Yog li ntawd, lawv muaj aerodynamic zoo dua.
kev sib tw
A nam piv tis yuav tsim tsawg induced luag tshaj ib tug tsawg nam piv tis vim hais tias muaj tsawg cua cuam tshuam ntawm lub ntsis ntawm ib tug ntev, nyias tis. Yog li ntawd, inducedkev tiv thaiv tuaj yeem ua rau inversely proportional rau proportionality, txawm li cas paradoxical nws yuav suab. Lub tshuab nqa nqa tuaj yeem hloov pauv los ntawm kev ntxuav tawm, twisting lub tis ib ncig kom txo qhov poob ntawm tis, thiab los ntawm kev hloov cov airfoil ze ntawm tis. Qhov no tso cai rau koj kom tau txais kev nqa ntau dua los ze rau lub hauv paus tis thiab tsawg dua rau lub tis, uas ua rau txo qis ntawm lub zog ntawm lub tis vortices thiab, raws li, kev txhim kho hauv aerodynamic zoo ntawm lub dav hlau.
Nyob hauv keeb kwm ntawm aircraft tsim
Ntawm qee lub dav hlau thaum ntxov cov fins tau teeb tsa ntawm cov lus qhia ntawm cov tails. Tom qab lub dav hlau muaj qhov sib txawv tis zoo los txo qhov kev siv ntawm cov vortices thiab ua tiav qhov siab tshaj plaws nqa-rau-drag piv.
Rooftop impeller roj tso tsheb hlau luam tuaj yeem muab qee qhov txiaj ntsig los ntawm kev tiv thaiv huab cua tsis txaus nyob ib puag ncig tis. Tam sim no lawv tau siv ntau lub dav hlau. Lub aerodynamic zoo ntawm DC-10 yog deservedly xam revolutionary nyob rau hauv no hais txog. Txawm li cas los xij, niaj hnub kev lag luam aviation tau ntev tau rov ua dua nrog ntau cov qauv siab dua.
Drag-rau-drag formula: piav qhia yooj yim
txhawm rau suav tag nrho cov kev tawm tsam nws yog ib qho tsim nyog yuav tsum tau coj mus rau hauv tus lej hu ua parasitic resistance. Txij li thaum induced luag yog inversely proportional rau lub square ntawm airspeed (ntawm ib tug muab lift), thaum cab cab yog ncaj qha proportional rau nws, tag nrho cov drag nkhaus qhia qhov tsawg kawg nkaus ceev. Lub dav hlau,ya nyob rau hauv xws li ceev, ua hauj lwm nrog zoo aerodynamic zoo. Raws li cov kev sib npaug saum toj no, qhov ceev ntawm qhov tsawg kawg nkaus kuj tshwm sim ntawm qhov ceev ntawm qhov induced resistance yog sib npaug rau cov kab mob parasitic. Qhov no yog qhov ceev ntawm qhov zoo tshaj plaws swb lub kaum sab xis mus txog rau lub dav hlau idle. Txhawm rau kom tsis txhob muaj qhov tsis pom tseeb, xav txog cov qauv ntawm qhov piv txwv ntawm lub dav hlau:
Txoj kev txuas ntxiv ntawm cov qauv kuj tseem xav paub ntau ntxiv (daim duab hauv qab no). Kev ya siab dua, qhov twg huab cua nyias dua, yuav ua rau kom qhov nrawm ntawm qhov tsawg kawg nkaus rub, thiab yog li nws tso cai rau kev mus nrawm dua ntawm tib tus nqi. roj.
Yog tias lub dav hlau ya ntawm nws qhov siab tshaj plaws uas tau tso cai, tom qab ntawd qhov siab ntawm huab cua ceev yuav muab qhov zoo tshaj plaws aerodynamic zoo. Qhov siab tshaj plaws ntawm qhov siab tshaj plaws thiab qhov siab tshaj plaws ntawm qhov siab tshaj plaws tuaj yeem hloov pauv thaum lub davhlau.
Kev mob siab
Speed rau qhov siab tshaj plaws (piv txwv li lub sijhawm nyob hauv huab cua) yog qhov ceev rau kev siv roj tsawg kawg nkaus thiab tsawg dua rau qhov siab tshaj plaws. Roj noj yog xam raws li cov khoom ntawm lub hwj chim uas yuav tsum tau thiab cov kev siv roj ib lub cav (roj noj ib chav tsev ntawm lub hwj chim). Lub zog xav tau yog sib npaug rau lub sijhawm rub.
History
Txoj kev loj hlob ntawm aerodynamics niaj hnub pib tsuas yog hauv XVIIcenturies, tab sis aerodynamic rog tau siv los ntawm tib neeg rau ntau txhiab xyoo nyob rau hauv sailboats thiab windmills, thiab cov duab thiab cov dab neeg ntawm lub davhlau tshwm nyob rau hauv tag nrho cov ntaub ntawv keeb kwm thiab tej hauj lwm ntawm kos duab, xws li ancient Greek lus dab neeg ntawm Icarus thiab Daedalus. Cov ntsiab lus tseem ceeb ntawm kev txuas ntxiv, kev tiv thaiv thiab kev siab gradients tshwm sim hauv kev ua haujlwm ntawm Aristotle thiab Archimedes.
Nyob rau xyoo 1726, Sir Isaac Newton tau los ua thawj tus neeg los tsim txoj kev xav ntawm huab cua tiv thaiv, ua rau nws yog ib qho ntawm thawj qhov kev sib cav txog aerodynamic zoo. Dutch-Swiss Mathematician Daniel Bernish Bernoulli tau sau cov kev sib raug zoo hauv nruab nrab ntawm cov kev sib raug zoo ntawm cov kev sib raug zoo ntawm cov kev sib raug zoo ntawm cov kev sib raug zoo ntawm cov kev sib raug zoo ntawm cov kev sib raug zoo, uas muaj ib txoj hauv kev rau xam Aerodynamic nqa aerodynamic nqa. Xyoo 1757, Leonhard Euler tau luam tawm ntau qhov sib npaug Euler, uas tuaj yeem siv rau ob qho tib si compressible thiab incompressible flows. Qhov sib npaug Euler tau txuas ntxiv kom suav nrog qhov cuam tshuam ntawm viscosity hauv thawj ib nrab ntawm xyoo 1800, ua rau Navier-Stokes sib npaug. Aerodynamic kev ua tau zoo / aerodynamic zoo ntawm lub ncov qaumteb qabteb twb nrhiav tau nyob ib ncig ntawm lub sij hawm.
Raws li cov xwm txheej no, nrog rau kev tshawb fawb hauv lawv lub qhov cua, cov kwv tij Wright tau ya thawj lub dav hlau thaum Lub Kaum Ob Hlis 17, 1903.
Type of aerodynamics
Aerodynamic teeb meem yog cais los ntawm cov dej ntws los yog cov khoom ntws, nrog rau cov yam ntxwv xws li kev tshaj tawm, compressibility thiab viscosity. Lawv feem ntau muab faib ua ob hom:
- Sab nraud aerodynamics yog kev kawm txog kev ntws ntawm cov khoom ntawm ntau yam duab. Piv txwv ntawm sab nraud aerodynamics yog qhov kev ntsuam xyuas ntawm nqa thiab rub ntawm lub dav hlau, lossis cov kev poob siab uas ua rau pem hauv ntej ntawm lub qhov ntswg missile.
- Internal aerodynamics yog kev kawm txog kev ntws los ntawm cov khoom hauv cov khoom. Piv txwv li, hauv aerodynamics npog txoj kev kawm ntawm airflow los ntawm lub dav hlau engine los yog los ntawm ib tug cua txias chimney.
Aerodynamic teeb meem kuj tuaj yeem raug cais raws li qhov nrawm nrawm hauv qab lossis ze ntawm lub suab nrawm.
Qhov teeb meem hu ua:
- subsonic, yog tias txhua qhov nrawm ntawm qhov teeb meem tsawg dua qhov nrawm ntawm lub suab;
- transonic yog tias muaj qhov nrawm hauv qab thiab siab dua qhov nrawm ntawm lub suab (feem ntau yog thaum tus yam ntxwv ceev yog kwv yees li sib npaug ntawm lub suab nrawm);
- supersonic, thaum tus yam ntxwv ntws nrawm tshaj qhov nrawm ntawm lub suab;
- hypersonic, thaum lub nrawm nrawm dua li qhov nrawm ntawm lub suab.
Aerodynamicists tsis pom zoo rau lub ntsiab txhais ntawm hypersonic flow.
Qhov cuam tshuam ntawm viscosity ntawm ntws dictates qhov kev faib thib peb. Qee qhov teeb meem tsuas yog muaj qhov cuam tshuam me me xwb, qhov twg qhov viscosity tuaj yeem suav tias yog qhov tsis txaus ntseeg. Kwv yees rau cov teeb meem no yog hu ua invisciddej ntws. Flows uas viscosity tsis tuaj yeem tsis quav ntsej yog hu ua viscous flows.
Compressibility
Ib qho ntws ruaj khov yog qhov dej ntws uas lub ntom ntom yog tas li ob qho tib si hauv lub sijhawm thiab chaw. Txawm hais tias tag nrho cov kua dej tiag tiag yog compressible, ntws feem ntau kwv yees li incompressible yog tias qhov kev hloov pauv ntawm qhov ntom ua rau tsuas yog hloov me me hauv cov txiaj ntsig suav. Qhov no feem ntau yog thaum tus nqi ntws zoo hauv qab lub suab nrawm. Cov teebmeem ntawm compressibility yog qhov tseem ceeb ntawm qhov nrawm ze lossis siab dua qhov nrawm ntawm lub suab. Tus lej Mach yog siv los ntsuas qhov ua tau ntawm incompressibility, txwv tsis pub cov teebmeem compressibility yuav tsum suav nrog.
Raws li txoj kev xav ntawm aerodynamics, qhov ntws yog suav tias yog compressible yog tias qhov ceev hloov pauv raws txoj kab. Qhov no txhais tau hais tias, nyob rau hauv sib piv rau ib tug incompressible flow, kev hloov nyob rau hauv ceev yog coj mus rau hauv tus account. Feem ntau, qhov no yog cov ntaub ntawv thaum Mach tus naj npawb ntawm ib feem lossis tag nrho cov dej ntws ntau tshaj 0.3. Mach tus nqi ntawm 0.3 yog qhov tsis txaus ntseeg, tab sis nws yog siv vim tias cov pa roj ntws hauv qab tus nqi no nthuav tawm tsawg dua 5% kev hloov pauv. Tsis tas li ntawd, qhov kev hloov pauv siab tshaj plaws ntawm 5% tshwm sim ntawm qhov chaw stagnation (qhov taw tes ntawm cov khoom uas qhov kev khiav nrawm yog xoom), thaum qhov ceev ntawm qhov seem ntawm cov khoom yuav qis dua. Transonic, supersonic thiab hypersonic ntws yog txhua yam compressible.
Zoo kawg
Aerodynamics yog ib qho kev tshawb fawb tseem ceeb tshaj plaws hauv ntiaj teb niaj hnub no. Nws muab rau pebtsim cov dav hlau zoo, nkoj, tsheb thiab comic shuttles. Nws ua lub luag haujlwm loj hauv kev tsim cov riam phom niaj hnub no - ballistic missiles, boosters, torpedoes thiab drones. Tag nrho cov no yuav ua tsis tau yog tias nws tsis yog rau cov ntsiab lus niaj hnub siab tshaj ntawm aerodynamic zoo.
Yog li, cov tswv yim hais txog cov ntsiab lus ntawm tsab xov xwm tau hloov pauv los ntawm qhov zoo nkauj, tab sis kev xav tsis zoo txog Icarus, mus rau kev ua haujlwm thiab ua haujlwm tiag tiag aircraft uas tshwm sim thaum pib ntawm lub xyoo pua xeem. Niaj hnub no peb tsis tuaj yeem xav txog peb lub neej yam tsis muaj tsheb, nkoj thiab dav hlau, thiab cov tsheb no txuas ntxiv txhim kho nrog kev ua haujlwm tshiab hauv aerodynamics.
Qhov zoo tshaj plaws aerodynamic ntawm gliders yog qhov ua tiav tiag tiag hauv lawv lub sijhawm. Thaum xub thawj, txhua qhov kev tshawb pom hauv cheeb tsam no tau tsim los ntawm kev paub daws teeb meem, qee zaum sib nrauj los ntawm kev muaj tiag, kev suav cov theoretical, uas tau ua los ntawm Fab Kis thiab German lej hauv lawv lub chaw soj nstuam. Tom qab ntawd, tag nrho lawv cov qauv tau siv rau lwm yam, zoo heev (los ntawm cov qauv ntawm lub xyoo pua 18th) lub hom phiaj, xws li suav cov duab zoo tagnrho thiab ceev ntawm lub dav hlau yav tom ntej. Nyob rau hauv lub xyoo pua puv 19, cov cuab yeej no tau pib ua ntau yam, pib nrog gliders thiab airships, cov neeg European tau maj mam hloov mus rau kev tsim dav hlau. Cov yav tas yog thawj zaug siv tshwj xeeb rau kev ua tub rog. Lub aces ntawm Thawj Ntiaj Teb Tsov Rog Thoob Ntiaj Teb tau qhia tias qhov teeb meem ntawm kev tswj hwm huab cua tseem ceeb npaum li cas rau txhua lub tebchaws, thiab cov engineers ntawm lub sijhawm interwar pom tias cov dav hlau zoo li no tsis yog rau cov tub rog nkaus xwb, tab sis kuj rau cov pej xeem.hom phiaj. Sij hawm dhau mus, kev dav hlau dav hlau tau nkag mus rau hauv peb lub neej, thiab niaj hnub no tsis muaj ib lub xeev tuaj yeem ua yam tsis muaj nws.
