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Multiphase Smoothed Particle Hydrodynamics Modeling of Supercooled Large Droplets Impingement and Solidification at In-Flight Icing Conditions.

紀錄類型:	書目-電子資源 : Monograph/item
正題名/作者:	Multiphase Smoothed Particle Hydrodynamics Modeling of Supercooled Large Droplets Impingement and Solidification at In-Flight Icing Conditions./
作者:	Cui, Xiangda.
面頁冊數:	1 online resource (118 pages)
附註:	Source: Dissertations Abstracts International, Volume: 83-10, Section: B.
Contained By:	Dissertations Abstracts International83-10B.
標題:	Aviation. -
電子資源:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=29043570click for full text (PQDT)
ISBN:	9798209934851

Multiphase Smoothed Particle Hydrodynamics Modeling of Supercooled Large Droplets Impingement and Solidification at In-Flight Icing Conditions.
Cui, Xiangda.

Multiphase Smoothed Particle Hydrodynamics Modeling of Supercooled Large Droplets Impingement and Solidification at In-Flight Icing Conditions. - 1 online resource (118 pages)

Source: Dissertations Abstracts International, Volume: 83-10, Section: B.

Thesis (Ph.D.)--McGill University (Canada), 2021.

Includes bibliographical references

Encounters with Supercooled Large Droplets (SLD) pose a danger to aircraft, as they can cause ice accretion beyond the reach of ice protection systems. In-flight icing effects must meet the regulations of airworthiness authorities in order for a new class of aircraft to obtain a type certification. Since flights into natural icing conditions and wind/icing tunnel tests cannot fully explore the SLD icing envelope, Computational Fluid Dynamics (CFD) has become an indispensable tool for assessing in-flight icing effects. However, the SLD modules of such in-flight icing simulation codes rely on empirical data or extrapolation from low-speed experiments. This thesis aims to develop a multiphase Smoothed Particle Hydrodynamics (SPH) solver for conducting "numerical experiments" of SLD impingement at flight speeds, to ultimately yield a macroscopic SLD model that can be embedded into in-flight icing simulation codes.SPH is a mesh-free CFD method suitable for SLD problems as it can handle complex interfaces and model multi-phase physics. In the multiphase SPH framework presented here, the inviscid momentum and energy equations are solved for flow and heat transfer, along with an equation of state linking pressure and density. A multiphase model is used to represent interfacial flows, and a fixed ghost particle method to enforce boundary conditions. Artificial viscous and diffusive terms are employed to smooth physical fields and decrease numerical instability, while a particle shifting technique is used to alleviate anisotropic particle distribution. Several numerical techniques are proposed to model the complex physics of SLD impingement such as a contact angle model to represent the non-wetting properties of hydrophobic surfaces, a latent heat model to account for phase change and a supercooled solidification model to capture dendritic freezing.The solver is validated against a series of experimental results, showing good agreement. It is then first applied to droplets impinging at flight speeds on a water film to study the effects on the post-impact water crown of droplet speed and diameter, surface tension, water film thickness, and impact angle. Droplets impacting on cold solid surfaces are then simulated to study freezing time and post-impact ice particle distribution for a range of speeds and impact angles. Following this, an improved contact angle model is used to study the interaction between droplets and hydrophobic/superhydrophobic coatings. Finally, SLD impinging on ice surfaces are studied via a supercooled solidification model, with supercooling degree and impact speed effects on residual ice analyzed.This thesis thus develops an SPH numerical framework capable of simulating SLD impingement and solidification at in-flight icing conditions. It provides a toolset for comprehensive parametric studies of SLD impingement, paving the way for a macroscopic SLD model for in-flight icing simulation codes.

Electronic reproduction.
Ann Arbor, Mich. :
ProQuest,
2023

Mode of access: World Wide Web

ISBN: 9798209934851Subjects--Topical Terms:

873136
Aviation.
Index Terms--Genre/Form:

542853
Electronic books.

Multiphase Smoothed Particle Hydrodynamics Modeling of Supercooled Large Droplets Impingement and Solidification at In-Flight Icing Conditions.
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502 $a Thesis (Ph.D.)--McGill University (Canada), 2021.
504 $a Includes bibliographical references
520 $a Encounters with Supercooled Large Droplets (SLD) pose a danger to aircraft, as they can cause ice accretion beyond the reach of ice protection systems. In-flight icing effects must meet the regulations of airworthiness authorities in order for a new class of aircraft to obtain a type certification. Since flights into natural icing conditions and wind/icing tunnel tests cannot fully explore the SLD icing envelope, Computational Fluid Dynamics (CFD) has become an indispensable tool for assessing in-flight icing effects. However, the SLD modules of such in-flight icing simulation codes rely on empirical data or extrapolation from low-speed experiments. This thesis aims to develop a multiphase Smoothed Particle Hydrodynamics (SPH) solver for conducting "numerical experiments" of SLD impingement at flight speeds, to ultimately yield a macroscopic SLD model that can be embedded into in-flight icing simulation codes.SPH is a mesh-free CFD method suitable for SLD problems as it can handle complex interfaces and model multi-phase physics. In the multiphase SPH framework presented here, the inviscid momentum and energy equations are solved for flow and heat transfer, along with an equation of state linking pressure and density. A multiphase model is used to represent interfacial flows, and a fixed ghost particle method to enforce boundary conditions. Artificial viscous and diffusive terms are employed to smooth physical fields and decrease numerical instability, while a particle shifting technique is used to alleviate anisotropic particle distribution. Several numerical techniques are proposed to model the complex physics of SLD impingement such as a contact angle model to represent the non-wetting properties of hydrophobic surfaces, a latent heat model to account for phase change and a supercooled solidification model to capture dendritic freezing.The solver is validated against a series of experimental results, showing good agreement. It is then first applied to droplets impinging at flight speeds on a water film to study the effects on the post-impact water crown of droplet speed and diameter, surface tension, water film thickness, and impact angle. Droplets impacting on cold solid surfaces are then simulated to study freezing time and post-impact ice particle distribution for a range of speeds and impact angles. Following this, an improved contact angle model is used to study the interaction between droplets and hydrophobic/superhydrophobic coatings. Finally, SLD impinging on ice surfaces are studied via a supercooled solidification model, with supercooling degree and impact speed effects on residual ice analyzed.This thesis thus develops an SPH numerical framework capable of simulating SLD impingement and solidification at in-flight icing conditions. It provides a toolset for comprehensive parametric studies of SLD impingement, paving the way for a macroscopic SLD model for in-flight icing simulation codes.
520 $a L'encontre en vol de grosses gouttelettes surfondues (Supercooled Large Droplets, soit SLD) presente un danger pour les aeronefs, en causant un cumul de givre depassant la portee des systemes de protection. De tels effets doivent etre soigneusement examines conformement aux reglements des autorites de certification de la securite aerienne, avant d'obtenir un certificat de vol en mode givrant. Etant donne que les essais en soufflerie ou en vol ne permettent pas l'exploration complete de l'enveloppe de vol en mode givrant, plus particulierement pour les SLD, la simulation numerique (Computational Fluid Dynamics, soit CFD), est un outil indispensable pour evaluer de tels effets. Toutefois, les modules SLD qu'utilisent les logiciels de simulation du givrage en vol se basent soit sur des donnees empiriques, soit sur une extrapolation d'experiences a basse vitesse. Il existe donc un besoin pressant de donnees numeriques de l'impact des SLD a des vitesses de vol beaucoup plus elevees qui puissent aboutir a un modele SLD macroscopique integre aux logiciels de simulation du givrage en vol.L'hydrodynamique des particules lissees (Smoothed Particle Hydrodynamics, soit SPH) est une methode CFD appropriee pour la simulation des SLD car elle permet, sans maillage, de gerer des interfaces complexes et de modeliser la physique multiphasique des melanges eau-glace. Dans le cadre SPH multiphasique presente dans cette these, les equations de bilan de la quantite de mouvement et de l'energie sont resolues pour l'ecoulement et le transfert de chaleur, avec une equation d'etat explicitement reliant pression et densite. Un modele multiphasique represente les flux inter faciaux, et une methode de particules fantomes fixes est choisie pour construire certaines conditions aux parois. Un terme visqueux artificiel et un terme diffusif sont utilises pour lisser les champs physiques et reduire l'instabilite numerique, et une technique de deplacement des particules pour rendre la distribution des particules moins anisotrope. Une gamme de techniques numeriques sont de plus proposees pour la modelisation de la physique complexe de l'impact des SLD. Des modeles sont proposes pour l'angle de contact des surfaces hydrophobes, la chaleur latente pour tenir compte des changements de phase, et de solidification surfondue pour capturer la congelation dendritique.Le solveur est valide versus une panoplie de resultats experimentaux, demontrant une bonne concordance. Il est applique aux gouttelettes entrant en collision, a des vitesses de vol, avec un film d'eau pour etudier les effets sur la couronne d'eau de la vitesse et diametre des gouttelettes, de la tension superficielle, la distribution des particules, l'epaisseur du film et de l'angle d'impact. Les gouttelettes impactant les surfaces solides froides sont ensuite simulees pour etudier le temps de congelation et la distribution des particules rebondissant a differentes vitesses et angles. En complement, l'interaction entre les gouttelettes et les revetements hydrophobes / super hydrophobes est examinee en utilisant un modele d'angle de contact pouvant mieux representer les proprietes non mouillantes. Finalement, les simulations des SLD impactant les surfaces de glace sont menees par un modele de solidification en surfusion permettant.
533 $a Electronic reproduction. $b Ann Arbor, Mich. : $c ProQuest, $d 2023
538 $a Mode of access: World Wide Web
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650 4 $a Cold. $3 560283
650 4 $a Hydrophobic surfaces. $3 714069
650 4 $a Aerospace engineering. $3 1002622
650 4 $a Engineering. $3 586835
655 7 $a Electronic books. $2 lcsh $3 542853
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773 0 $t Dissertations Abstracts International $g 83-10B.
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=29043570 $z click for full text (PQDT)