New Aerodynamic Aspects of Aircraft De/Anti-icing fluids

Pekka Koivisto

New Aerodynamic Aspects of Aircraft De/Anti-icing fluids

Julkaisun otsikon käännös: Uusia näkökulmia lentokoneen jäänpoisto- ja estonesteiden aerodynamiikkaan

Pekka Koivisto

Energia- ja konetekniikan laitos

Tutkimustuotos: Doctoral Thesis › Collection of Articles

Abstrakti

Tämä väitöskirja lukeutuu aerodynamiikan ja nestemekaniikan tutkimusalaan. Työssä on tutkittu liikennelentokoneen maassa käytettyjen jäänpoisto- ja estonesteiden jäämistä sekä kylmän polttoaineen aiheuttamasta huurteesta (CSFF) syntyvien epäpuhtauksien aerodynaamisia vaikutuksia. Tutkimus koostuu pääasiassa tuulitunnelikokeista. Työhön sisältyy myös joitakin laskennallisia virtaussimulointeja (CFD), jotka auttavat hahmottamaan jäänpoisto- ja estonesteiden poistumiseen liittyviä virtausmekaanisia ilmiöitä. Väitöskirja koostuu neljästä kansainvälisestä lehtijulkaisusta. Kaksi ensimmäistä julkaisua käsittelee jäänestonestettä sekä kylmän polttoaineen aiheuttamaa huurretta (CSFF) aerodynaamisina epäpuhtauksina, jotka heikentävät siiven saavutusarvoja ja kaksi jälkimmäistä julkaisua käsittelee jäänpoisto- ja estonesteiden poistumisen virtausmekaniikkaa. Ensimmäisissä julkaisuissa tutkitaan kahta erilaista siipiprofiilimallia ja jälkimmäisissä julkaisuissa nesteiden poistumismekaniikkaa tarkastellaan tasolevymalleilla. Kaikki tuulitunnelikokeet on suunniteltu simuloimaan liikennelentokoneen lentoonlähtötilannetta kiihdyttämällä tuulitunneli tyhjäkäyntinopeudelta ilmanopeuteen 60 m/s, joka vastaa liikennekoneen irtoamisnopeutta. Ensimmäisessä julkaisussa tarkastellaan jäänestonesteen niin kutsutun sekundääriaallon osuutta nesteen aikaansaamaan nostovoimavähenemään liikennelentokoneen irtoamisvaiheessa ja alkunousussa. Myös siipiprofiilin etureunasolakon geometrian vaikutusta sekundääriaaltoon tutkitaan. Toinen julkaisu on toistaiseksi ainoa julkinen tarkastelu, jossa aitoa huurretta (CSFF) on tutkittu siiven pinnan epäpuhtautena kiinteän santapaperityyppisen karheuden sijasta, joka on ollut aiemmin omaksuttu tapa käsitellä huurteen vaikutusta. Kahdessa viimeisessä julkaisussa tutkitaan jäänpoisto- ja estonesteiden poistumisilmiötä aerodynaamisilta pinnoilta. Kinemaattisen aallon käsitteen osoitetaan selittävän nesteen poistumisliikkeen tasolevyllä, kun kiihtyvä ilmavirta kohdistuu jäänpoisto- tai estonesteen pinnalle. Nesteiden viskositeetin vaikutusta on myös käsitelty. Lisäksi on kehitetty uusi skaalausmenetelmä nesteen poistumiselle. Väitöskirjan tieteelliset saavutukset voidaan tiivistää seuraavasti: (1) sekundääriaallon osuus nostovoimavähenemään lentoonlähdössä ja siipiprofiilin sekä sen etureunasolakon geometrian vaikutus sekundääriaaltoon on arvioitu, (2) kylmän polttoaineen aiheuttaman huurteen (CSFF) aikaansaama aerodynaaminen epäpuhtaus on osoitettu olevan tilapäinen ilmiö, (3) jäänpoisto- ja estonesteiden pinnalle kiihtyvän ilmavirran aiheuttamien aaltojen osuutta nesteen poistumiseen on selkiinnytetty ja yksinkertaistettuja malleja on muodostettu nesteen poistumiselle tasolevyltä kinemaattisten aaltojen käsitettä hyödyntäen (4) on muotoiltu skaalausmenetelmä nesteen poistumisen redusoimiseksi samalle käyrälle eri kokoisille kappaleille ja eri tavoin muuttuville tuulitunnelinopeuksille.

Julkaisun otsikon käännös	Uusia näkökulmia lentokoneen jäänpoisto- ja estonesteiden aerodynamiikkaan
Alkuperäiskieli	Englanti
Pätevyys	Tohtorintutkinto
Myöntävä instituutio	Aalto-yliopisto
Valvoja/neuvonantaja	Vuorinen, Ville, Vastuuprofessori Hellsten, Antti, Ohjaaja
Kustantaja	Aalto University
Painoksen ISBN	978-952-64-0425-7
Sähköinen ISBN	978-952-64-0426-4
Tila	Julkaistu - 2021
OKM-julkaisutyyppi	G5 Artikkeliväitöskirja

Tutkimusalat

jäänpoisto- ja estonesteet
aerodynaamiset epäpuhtaudet
huurre

Pääsy asiakirjaan

http://urn.fi/URN:ISBN:978-952-64-0426-4

Siteeraa tätä

@phdthesis{0847f8d9be7a4ab8b32499af4f0eabe5,

title = "New Aerodynamic Aspects of Aircraft De/Anti-icing fluids",

abstract = "This dissertation belongs to the research areas of aerodynamics and fluid dynamics. De/anti-icing fluids and so called cold soaked fuel frost (CSFF) are examined as aerodynamic contaminants originating during a ground stay of an airliner. The research consists mainly of experiments in a wind tunnel. Additionally, some CFD simulations are included to enhance the perception of the de/anti-icing fluid flow-off phenomena. The dissertation consists of four journal publications. The two first publications consider anti-icing fluid and CSFF as aerodynamic contaminations degrading performance of a wing and the two latter publications consider the de/anti-icing fluid flow-off phenomenon. In the two first publications two different wing section models are studied whereas the fluid flow-off phenomenon is studied on the surface of flat plate models. All wind tunnel tests are designed to simulate a take-off sequence of an airliner by accelerating the airflow from idle speed to 60 m/s which represents the lift-off speed of an airliner. In the first publication the contribution of the so-called secondary wave on the anti-icing fluid induced lift degradation of a wing section at the lift off and during initial climb of an airliner is considered. The effect of wing section slat geometry on the secondary wave is also studied. The second publication covers the first published experiments with authentic frost (CSFF) as an aerodynamic contamination over a wing surface instead of a fixed sandpaper type of roughness adopted in previous published studies. In the third and fourth publications de/anti-icing fluid flow-off phenomenon is studied. The concept of kinematic waves on the fluid surface when subjected to an accelerating airflow is demonstrated to explain the fluid transfer on a flat plate. The effect of fluid viscosity is addressed and a scaling law for fluid flow-off is developed. The scientific novelties included in this dissertation may be summarised as follows: (1) the contribution of secondary wave on the lift loss during takeoff and the effect of wing section and slat geometry on the secondary wave has been assessed, (2) the transient nature of CSFF as an aerodynamic contamination during takeoff has been demonstrated, (3) the role of wave motion on the surface of the de/anti-icing fluid layer subjected to an airflow has been clarified and simplified models have been formulated to understand the relation between kinematic waves and fluid transfer on the flat plate surface and (4) a scaling method has been developed for similarity in fluid flow-off between different scales and wind tunnel speed sequences.",

keywords = "De/anti-icing fluids, aerodynamic contamination, CSFF, j{\"a}{\"a}npoisto- ja estonesteet, aerodynaamiset ep{\"a}puhtaudet, huurre, De/anti-icing fluids, aerodynamic contamination, CSFF",

author = "Pekka Koivisto",

year = "2021",

language = "English",

isbn = "978-952-64-0425-7",

series = "Aalto University publication series DOCTORAL DISSERTATIONS",

publisher = "Aalto University",

number = "86",

address = "Finland",

school = "Aalto University",

}

TY - BOOK

T1 - New Aerodynamic Aspects of Aircraft De/Anti-icing fluids

AU - Koivisto, Pekka

PY - 2021

Y1 - 2021

N2 - This dissertation belongs to the research areas of aerodynamics and fluid dynamics. De/anti-icing fluids and so called cold soaked fuel frost (CSFF) are examined as aerodynamic contaminants originating during a ground stay of an airliner. The research consists mainly of experiments in a wind tunnel. Additionally, some CFD simulations are included to enhance the perception of the de/anti-icing fluid flow-off phenomena. The dissertation consists of four journal publications. The two first publications consider anti-icing fluid and CSFF as aerodynamic contaminations degrading performance of a wing and the two latter publications consider the de/anti-icing fluid flow-off phenomenon. In the two first publications two different wing section models are studied whereas the fluid flow-off phenomenon is studied on the surface of flat plate models. All wind tunnel tests are designed to simulate a take-off sequence of an airliner by accelerating the airflow from idle speed to 60 m/s which represents the lift-off speed of an airliner. In the first publication the contribution of the so-called secondary wave on the anti-icing fluid induced lift degradation of a wing section at the lift off and during initial climb of an airliner is considered. The effect of wing section slat geometry on the secondary wave is also studied. The second publication covers the first published experiments with authentic frost (CSFF) as an aerodynamic contamination over a wing surface instead of a fixed sandpaper type of roughness adopted in previous published studies. In the third and fourth publications de/anti-icing fluid flow-off phenomenon is studied. The concept of kinematic waves on the fluid surface when subjected to an accelerating airflow is demonstrated to explain the fluid transfer on a flat plate. The effect of fluid viscosity is addressed and a scaling law for fluid flow-off is developed. The scientific novelties included in this dissertation may be summarised as follows: (1) the contribution of secondary wave on the lift loss during takeoff and the effect of wing section and slat geometry on the secondary wave has been assessed, (2) the transient nature of CSFF as an aerodynamic contamination during takeoff has been demonstrated, (3) the role of wave motion on the surface of the de/anti-icing fluid layer subjected to an airflow has been clarified and simplified models have been formulated to understand the relation between kinematic waves and fluid transfer on the flat plate surface and (4) a scaling method has been developed for similarity in fluid flow-off between different scales and wind tunnel speed sequences.

AB - This dissertation belongs to the research areas of aerodynamics and fluid dynamics. De/anti-icing fluids and so called cold soaked fuel frost (CSFF) are examined as aerodynamic contaminants originating during a ground stay of an airliner. The research consists mainly of experiments in a wind tunnel. Additionally, some CFD simulations are included to enhance the perception of the de/anti-icing fluid flow-off phenomena. The dissertation consists of four journal publications. The two first publications consider anti-icing fluid and CSFF as aerodynamic contaminations degrading performance of a wing and the two latter publications consider the de/anti-icing fluid flow-off phenomenon. In the two first publications two different wing section models are studied whereas the fluid flow-off phenomenon is studied on the surface of flat plate models. All wind tunnel tests are designed to simulate a take-off sequence of an airliner by accelerating the airflow from idle speed to 60 m/s which represents the lift-off speed of an airliner. In the first publication the contribution of the so-called secondary wave on the anti-icing fluid induced lift degradation of a wing section at the lift off and during initial climb of an airliner is considered. The effect of wing section slat geometry on the secondary wave is also studied. The second publication covers the first published experiments with authentic frost (CSFF) as an aerodynamic contamination over a wing surface instead of a fixed sandpaper type of roughness adopted in previous published studies. In the third and fourth publications de/anti-icing fluid flow-off phenomenon is studied. The concept of kinematic waves on the fluid surface when subjected to an accelerating airflow is demonstrated to explain the fluid transfer on a flat plate. The effect of fluid viscosity is addressed and a scaling law for fluid flow-off is developed. The scientific novelties included in this dissertation may be summarised as follows: (1) the contribution of secondary wave on the lift loss during takeoff and the effect of wing section and slat geometry on the secondary wave has been assessed, (2) the transient nature of CSFF as an aerodynamic contamination during takeoff has been demonstrated, (3) the role of wave motion on the surface of the de/anti-icing fluid layer subjected to an airflow has been clarified and simplified models have been formulated to understand the relation between kinematic waves and fluid transfer on the flat plate surface and (4) a scaling method has been developed for similarity in fluid flow-off between different scales and wind tunnel speed sequences.

KW - De/anti-icing fluids

KW - aerodynamic contamination

KW - CSFF

KW - jäänpoisto- ja estonesteet

KW - aerodynaamiset epäpuhtaudet

KW - huurre

KW - De/anti-icing fluids

KW - aerodynamic contamination

KW - CSFF

M3 - Doctoral Thesis

SN - 978-952-64-0425-7

T3 - Aalto University publication series DOCTORAL DISSERTATIONS

PB - Aalto University

ER -

New Aerodynamic Aspects of Aircraft De/Anti-icing fluids

Abstrakti

Tutkimusalat

Pääsy asiakirjaan

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