Studies on Unmanned Atmospheric Flight

Timo Sailaranta

Studies on Unmanned Atmospheric Flight

Julkaisun otsikon käännös: Miehittämättömien lentolaitteiden lennon tarkastelua

Timo Sailaranta

Energia- ja konetekniikan laitos

Tutkimustuotos: Doctoral Thesis › Collection of Articles

Abstrakti

Tämä väitöskirja keskittyy miehittämättömien lentolaitteiden lennon tutkimukseen. Käsiteltäviä aihealueita ovat aerodynamiikka, lentomekaniikka, lennonohjaus ja hakeutuminen. Lisäksi tarkasteltaan optimointia mm. lentolaitteen ilmanvastuksen minimoinnin yhteydessä. Aerodynamiikan osa-alueella opinnäytteessä ehdotetaan Newtonin virtausteoriaan muutosta siten, että se ottaisi huomioon tiivistysaaltojen vaikutuksen virtauskentässä. Klassinen Newtonin teoria on käytännössä käytettävissä vain erittäin suurilla, hypersoonisilla nopeuksilla. Ehdotettu modifikaatio laajentaa menetelmän käytettävyyttä pienille ylisoonisille Machin luvuille asti. Kehitettyä menetelmää käytetään tässä työssä mm. runkomaisen geometrian painevastuksen minimoinnissa. Toisessa väitöksen osa-alueessa tarkastellaan luodin lentomekaniikka ja aerodynamiikkaa suurilla kohtauskulmilla. Tavoitteena on löytää mekanismeja, joilla nopeasti pyörivä luoti saadaan lennon loppuvaiheen alisoonisella alueella pysyvästi epästabiiliksi. Erityisesti nk. Magnus-ilmiön hyödyntämistä tutkitaan työssä numeerisin virtaussimuloinnein ja ratalaskuin. Esimerkiksi ylöspäin ammutun luodin iskeytymisnopeus olisi epästabiilin loppulennon tapauksessa pienehkö ja vastaavasti mahdollisen osuman aiheuttamat haitat vähäisiä. Kolmantena osa-alueena tutkitaan lentolaitteen lennon vakavoittamista älykkään rakenteen avulla. Työn tuloksena ehdotetaan siipien kiinnitykseen joustavaa mekanismia, joka vaimentaa lentolaitteen lennon aikaisia heilahteluja. Sopivasti viivästettynä mekanismi myös palauttaa ohjaamattoman lentolaitteen halutulle, alkuperäiselle lentoradalle. Neljäntenä osa-alueena työssä tarkastellaan adjoint-mallin (liittomallin) käyttöä ohjuksen maaliin hakeutumisessa. Tarkastelussa muodostetaan lineaarinen malli (Hamiltonian) hakeutumissilmukasta, jolloin laaditun yhtälöryhmän liittomalli tarjoaa mahdollisuuden integroida käänteisesti tarkastellun systeemin herkkyyksiä. Yhdellä tietokoneajolla voidaan tällöin korvata huomattava määrä ajan suhteen tehtyjä tarkasteluja. Menetelmää käytetään työssä arvioitaessa lentokoneelle sopivaa, lähes optimaalista tapaa liikehtiä ohjusta väistettäessä. Viidentenä aihepiirinä työssä on ilmakehän häiriöiden vaikutus lentolaitteen asentoheilahteluun ja tätä kautta hetkelliseen tutkapoikkipinta-alaan ja kohteen tunnistettavuuteen.

Julkaisun otsikon käännös	Miehittämättömien lentolaitteiden lennon tarkastelua
Alkuperäiskieli	Englanti
Pätevyys	Tohtorintutkinto
Myöntävä instituutio	Aalto-yliopisto
Valvoja/neuvonantaja	Siikonen, Timo, Vastuuprofessori
Kustantaja	Aalto University
Painoksen ISBN	978-952-60-6731-5
Sähköinen ISBN	978-952-60-6732-2
Tila	Julkaistu - 2016
OKM-julkaisutyyppi	G5 Artikkeliväitöskirja

Tutkimusalat

lentomekaniikka
aerodynamiikka

Pääsy asiakirjaan

http://urn.fi/URN:ISBN:978-952-60-6732-2Lisenssi: Määrittelemätön

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@phdthesis{ce150350fc82420d8bafbea9db55142a,

title = "Studies on Unmanned Atmospheric Flight",

abstract = "The thesis deals with topics emerging in the field of aerial flight of unmanned vehicles. In this framework, aerodynamics, flight mechanics, flight control and the guidance of unmanned vehicles are discussed. In addition, some issues related to vehicle design and flight optimization are considered. An underlying principle of the thesis has been to increase general knowledge concerning the flight of unmanned airborne vehicles. The work was carried out in order to benefit the industry. It is also hoped that the wide perspective of the thesis will support education on the university level. In the scope of pure aerodynamics, the thesis proposes a modification to the well-known Newtonian Flow theory. The Newtonian theory does not take into account information propagation to upstream and is applicable only for very high speed flows. The modification implicitly incorporates shock-wave effects addressing the information limited to travel upstream. This novel approach extends the method to cover also low and moderate supersonic speeds. The method was developed mainly for optimization purposes and the simple law form makes it easy to use in this context. The work portion concerning unguided vehicle flight mechanics is also linked to the real world through the pursuit to develop, in co-operation with industry, a {"}safe{"} bullet. In this part, high angle-of-attack aerodynamic interactions and the flight mechanics of a fast spinning bullet are studied in order to understand the phenomena of the fall of an upwards fired bullet. The ultimate goal is to ensure, under strongly unstable flight, retarding the impact velocity of a falling bullet beyond lethal. The vehicle instability mechanism is caused by an aerodynamic interaction called the Magnus effect. The third issue of the thesis is flight control and particularly a smart-structure based passive means to stabilize the flight of an unguided vehicle and minimize disturbance effects on the flight. Linear and non-linear theory studies are utilized and a concept of properly delayed turning fins is proposed. The fourth topic covers unmanned vehicle guidance.The transposed Hamiltonian reveals linearized system sensitivities and provides a powerful tool for any system analysis over the typical time-domain considerations. The approach is not as widely used as it should be, which is probably due to the quite obscure way of presenting the theory in textbooks under the title of {"}adjoint{"}. Finally, the thesis considers the effects of atmospheric turbulence on the momentary orientation of an airborne vehicle. The turbulence influences the radar cross section (RCS) of a vehicle and furthermore recognition of the target.",

keywords = "flight mechanics, aerodynamics, lentomekaniikka, aerodynamiikka, flight mechanics, aerodynamics",

author = "Timo Sailaranta",

year = "2016",

language = "English",

isbn = "978-952-60-6731-5",

series = "Aalto University publication series DOCTORAL DISSERTATIONS",

publisher = "Aalto University",

number = "59",

address = "Finland",

school = "Aalto University",

}

TY - BOOK

T1 - Studies on Unmanned Atmospheric Flight

AU - Sailaranta, Timo

PY - 2016

Y1 - 2016

N2 - The thesis deals with topics emerging in the field of aerial flight of unmanned vehicles. In this framework, aerodynamics, flight mechanics, flight control and the guidance of unmanned vehicles are discussed. In addition, some issues related to vehicle design and flight optimization are considered. An underlying principle of the thesis has been to increase general knowledge concerning the flight of unmanned airborne vehicles. The work was carried out in order to benefit the industry. It is also hoped that the wide perspective of the thesis will support education on the university level. In the scope of pure aerodynamics, the thesis proposes a modification to the well-known Newtonian Flow theory. The Newtonian theory does not take into account information propagation to upstream and is applicable only for very high speed flows. The modification implicitly incorporates shock-wave effects addressing the information limited to travel upstream. This novel approach extends the method to cover also low and moderate supersonic speeds. The method was developed mainly for optimization purposes and the simple law form makes it easy to use in this context. The work portion concerning unguided vehicle flight mechanics is also linked to the real world through the pursuit to develop, in co-operation with industry, a "safe" bullet. In this part, high angle-of-attack aerodynamic interactions and the flight mechanics of a fast spinning bullet are studied in order to understand the phenomena of the fall of an upwards fired bullet. The ultimate goal is to ensure, under strongly unstable flight, retarding the impact velocity of a falling bullet beyond lethal. The vehicle instability mechanism is caused by an aerodynamic interaction called the Magnus effect. The third issue of the thesis is flight control and particularly a smart-structure based passive means to stabilize the flight of an unguided vehicle and minimize disturbance effects on the flight. Linear and non-linear theory studies are utilized and a concept of properly delayed turning fins is proposed. The fourth topic covers unmanned vehicle guidance.The transposed Hamiltonian reveals linearized system sensitivities and provides a powerful tool for any system analysis over the typical time-domain considerations. The approach is not as widely used as it should be, which is probably due to the quite obscure way of presenting the theory in textbooks under the title of "adjoint". Finally, the thesis considers the effects of atmospheric turbulence on the momentary orientation of an airborne vehicle. The turbulence influences the radar cross section (RCS) of a vehicle and furthermore recognition of the target.

AB - The thesis deals with topics emerging in the field of aerial flight of unmanned vehicles. In this framework, aerodynamics, flight mechanics, flight control and the guidance of unmanned vehicles are discussed. In addition, some issues related to vehicle design and flight optimization are considered. An underlying principle of the thesis has been to increase general knowledge concerning the flight of unmanned airborne vehicles. The work was carried out in order to benefit the industry. It is also hoped that the wide perspective of the thesis will support education on the university level. In the scope of pure aerodynamics, the thesis proposes a modification to the well-known Newtonian Flow theory. The Newtonian theory does not take into account information propagation to upstream and is applicable only for very high speed flows. The modification implicitly incorporates shock-wave effects addressing the information limited to travel upstream. This novel approach extends the method to cover also low and moderate supersonic speeds. The method was developed mainly for optimization purposes and the simple law form makes it easy to use in this context. The work portion concerning unguided vehicle flight mechanics is also linked to the real world through the pursuit to develop, in co-operation with industry, a "safe" bullet. In this part, high angle-of-attack aerodynamic interactions and the flight mechanics of a fast spinning bullet are studied in order to understand the phenomena of the fall of an upwards fired bullet. The ultimate goal is to ensure, under strongly unstable flight, retarding the impact velocity of a falling bullet beyond lethal. The vehicle instability mechanism is caused by an aerodynamic interaction called the Magnus effect. The third issue of the thesis is flight control and particularly a smart-structure based passive means to stabilize the flight of an unguided vehicle and minimize disturbance effects on the flight. Linear and non-linear theory studies are utilized and a concept of properly delayed turning fins is proposed. The fourth topic covers unmanned vehicle guidance.The transposed Hamiltonian reveals linearized system sensitivities and provides a powerful tool for any system analysis over the typical time-domain considerations. The approach is not as widely used as it should be, which is probably due to the quite obscure way of presenting the theory in textbooks under the title of "adjoint". Finally, the thesis considers the effects of atmospheric turbulence on the momentary orientation of an airborne vehicle. The turbulence influences the radar cross section (RCS) of a vehicle and furthermore recognition of the target.

KW - flight mechanics

KW - aerodynamics

KW - lentomekaniikka

KW - aerodynamiikka

KW - flight mechanics

KW - aerodynamics

M3 - Doctoral Thesis

SN - 978-952-60-6731-5

T3 - Aalto University publication series DOCTORAL DISSERTATIONS

PB - Aalto University

ER -

Studies on Unmanned Atmospheric Flight

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Tutkimusalat

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