Numerical studies on industrial flows

Petteri Peltonen

Numerical studies on industrial flows

Julkaisun otsikon käännös: Numeerisia tutkimuksia teollisuusvirtauksista

Petteri Peltonen

Energia- ja konetekniikan laitos

Tutkimustuotos: Doctoral Thesis › Collection of Articles

Abstrakti

Väitöskirja kuuluu sovelletun fysiikan aihepiiriin, tarkemmin nestevirtauksen numeeriseen mallintamiseen teollisuussovelluksissa. Laskennallista virtausmekaniikkaa sovelletaan neljään eri virtaustilanteeseen. Jokaisen virtaustilanteen motivaatio ja tausta tulee yhteistyöstä suomalaisten teollisuusyritysten kanssa. Julkaisussa I prekursorien skoittumista ja kantajakaasun virtausilmiöitä tutkitaan kaupallisessa atomikerroskasvatusreaktorissa. Tavoitteena on ymmärtää virtausilmiöiden suhdetta atomikerroksen kasvuun. Julkaisun I numeeriset ja kokeelliset tulokset viittaavat siihen, että virtausilmiöt ja sekoittuminen vaikuttavat atomikerroksen muodostumiseen. Kun numeerisia tuloksia verrataan mitattuun atomikerroksen paksuuteen, huomataan kuitenkin että pelkkä prekursorien konsentraatio pinnoitettavalla kappaleella ei riitä kuvaamaan atomikerrosen kasvua. Julkaisussa II tutkitaan levy- ja puikkoripalämmönsiirtimien toimintaa putkivirtauksessa. Numeeriset tulokset osoittavat, että levylämmönsiirtimen kohdalla analyyttinen korrelaatio Nusseltin luvulle pätee hyvin sisimmille rivoille. Puikkoripalämmönsiirtimelle ripakohtainen Nusselt-luku sen sijaan vaihtelee merkittävästi. Julkaisussa III implementoidaan sekä käytetään haamufluidimenetelmää (ghost fluid method) kaksifaasivirtausyhtälöiden ratkaisuun. Tavoitteena on testata menetelmän toimivuutta meriteollisuudelle merkittävissä testisovelluksissa sekä verrata tuloksia OpenFOAM-kirjaston standardi kaksifaasivirtausratkaisijan antamiin tuloksiin. Julkaisussa huomataan, että GFM tarjoaa hieman parempia tuloksia kuin OpenFOAM-kirjaston perusratkaisumenetelmä. Tuloksissa ei kuitenkaan havaita selvää eroa menetelmien välillä. GFM-menetelmä sovelletaan Julkaisussa IV vapaan pinnan porrasvirtaukselle (free surface backward facing step). Julkaisussa tutkitaan erityisesti Reynolds-luvun vaikutusta syntyvään aaltomuotoon. Reynolds-luvun vaikutuksen huomataan olevan merkittävä ja tulos tarkoittaa, että malliskaalassa suoritetut mittaukset tai simuloinnit voivat poiketa täysmittakaavan vastaavista tuloksista.

Julkaisun otsikon käännös	Numeerisia tutkimuksia teollisuusvirtauksista
Alkuperäiskieli	Englanti
Pätevyys	Tohtorintutkinto
Myöntävä instituutio	Aalto-yliopisto
Valvoja/neuvonantaja	Vuorinen, Ville, Vastuuprofessori Kaario, Ossi, Ohjaaja
Kustantaja	Aalto University
Painoksen ISBN	978-952-64-0520-9
Sähköinen ISBN	978-952-64-0521-6
Tila	Julkaistu - 2021
OKM-julkaisutyyppi	G5 Artikkeliväitöskirja

Tutkimusalat

turbulenssi
laskennallinen virtausmekaniikka
kaksifaasivirtaus
lämmönsiirto

YK:n kestävän kehityksen tavoitteet

Tämä tuotos edistää seuraavia kestävän kehityksen tavoitteita:

Pääsy asiakirjaan

http://urn.fi/URN:ISBN:978-952-64-0521-6

Siteeraa tätä

@phdthesis{3d80fe8b7784473cbd05bdafe4043f6d,

title = "Numerical studies on industrial flows",

abstract = "The present thesis belongs to the field of applied physics, more precisely numerical simulation of industrial fluid flows. Computational fluid dynamics (CFD) simulations are applied to investigate four different flow scenarios. Particular focus is on usage of scale-resolving methods in CFD. Each of the studied flow scenarios is motivated by collaboration with the Finnish industry. In Publication I the gas flow phenomena are studied in a commercial atomic layer deposition (ALD) reactor to better understand the fluid flow effects on the surface growth. Both the numerical and experimental results in Publication I indicate that the surface growth depends on the mixing of the precursors and the carrier gas. However, comparison of the numerical results to the experiments reveals that the numerically obtained precursor concentrations are not sufficient to predict the surface growth rate. In Publication II the performance of a plate fin and a square pin fin heat exchangers is investigated in a constrained pipe flow. The numerical results show that for the planar fins the analytical Nusselt number correlation for channel flow applies in the interior fins. For the pin fins a large variation in the fin-averaged Nusselt number is observed. The downstream wake mixing characteristics are shown to match with experimental data. In Publication III, the ghost fluid method (GFM) for coupling the volume of fluid scalar equation and momentum equation is implemented and thoroughly tested in marine context. The results of the test cases indicate that GFM has moderate benefits over the standard volume fluid formulation in OpenFOAM but it does not clearly outperform the standard formulation either. Further, alternative formulations for the viscous term treatment are studied. In Publication IV, the implemented GFM is applied to study the Reynolds number scaling effect for a free surface backward facing step geometry for the first time using large-eddy simulation. The forming wave shape is shown to depend on the Reynolds number indicating that care should be taken when interpreting model scale simulations or experiments.",

keywords = "turbulence, computational fluid dynamics, two-phase flow, heat transfer, turbulenssi, laskennallinen virtausmekaniikka, kaksifaasivirtaus, l{\"a}mm{\"o}nsiirto, turbulence, computational fluid dynamics, two-phase flow, heat transfer",

author = "Petteri Peltonen",

year = "2021",

language = "English",

isbn = "978-952-64-0520-9",

series = "Aalto University publication series DOCTORAL DISSERTATIONS",

publisher = "Aalto University",

number = "130",

address = "Finland",

school = "Aalto University",

}

TY - BOOK

T1 - Numerical studies on industrial flows

AU - Peltonen, Petteri

PY - 2021

Y1 - 2021

N2 - The present thesis belongs to the field of applied physics, more precisely numerical simulation of industrial fluid flows. Computational fluid dynamics (CFD) simulations are applied to investigate four different flow scenarios. Particular focus is on usage of scale-resolving methods in CFD. Each of the studied flow scenarios is motivated by collaboration with the Finnish industry. In Publication I the gas flow phenomena are studied in a commercial atomic layer deposition (ALD) reactor to better understand the fluid flow effects on the surface growth. Both the numerical and experimental results in Publication I indicate that the surface growth depends on the mixing of the precursors and the carrier gas. However, comparison of the numerical results to the experiments reveals that the numerically obtained precursor concentrations are not sufficient to predict the surface growth rate. In Publication II the performance of a plate fin and a square pin fin heat exchangers is investigated in a constrained pipe flow. The numerical results show that for the planar fins the analytical Nusselt number correlation for channel flow applies in the interior fins. For the pin fins a large variation in the fin-averaged Nusselt number is observed. The downstream wake mixing characteristics are shown to match with experimental data. In Publication III, the ghost fluid method (GFM) for coupling the volume of fluid scalar equation and momentum equation is implemented and thoroughly tested in marine context. The results of the test cases indicate that GFM has moderate benefits over the standard volume fluid formulation in OpenFOAM but it does not clearly outperform the standard formulation either. Further, alternative formulations for the viscous term treatment are studied. In Publication IV, the implemented GFM is applied to study the Reynolds number scaling effect for a free surface backward facing step geometry for the first time using large-eddy simulation. The forming wave shape is shown to depend on the Reynolds number indicating that care should be taken when interpreting model scale simulations or experiments.

AB - The present thesis belongs to the field of applied physics, more precisely numerical simulation of industrial fluid flows. Computational fluid dynamics (CFD) simulations are applied to investigate four different flow scenarios. Particular focus is on usage of scale-resolving methods in CFD. Each of the studied flow scenarios is motivated by collaboration with the Finnish industry. In Publication I the gas flow phenomena are studied in a commercial atomic layer deposition (ALD) reactor to better understand the fluid flow effects on the surface growth. Both the numerical and experimental results in Publication I indicate that the surface growth depends on the mixing of the precursors and the carrier gas. However, comparison of the numerical results to the experiments reveals that the numerically obtained precursor concentrations are not sufficient to predict the surface growth rate. In Publication II the performance of a plate fin and a square pin fin heat exchangers is investigated in a constrained pipe flow. The numerical results show that for the planar fins the analytical Nusselt number correlation for channel flow applies in the interior fins. For the pin fins a large variation in the fin-averaged Nusselt number is observed. The downstream wake mixing characteristics are shown to match with experimental data. In Publication III, the ghost fluid method (GFM) for coupling the volume of fluid scalar equation and momentum equation is implemented and thoroughly tested in marine context. The results of the test cases indicate that GFM has moderate benefits over the standard volume fluid formulation in OpenFOAM but it does not clearly outperform the standard formulation either. Further, alternative formulations for the viscous term treatment are studied. In Publication IV, the implemented GFM is applied to study the Reynolds number scaling effect for a free surface backward facing step geometry for the first time using large-eddy simulation. The forming wave shape is shown to depend on the Reynolds number indicating that care should be taken when interpreting model scale simulations or experiments.

KW - turbulence

KW - computational fluid dynamics

KW - two-phase flow

KW - heat transfer

KW - turbulenssi

KW - laskennallinen virtausmekaniikka

KW - kaksifaasivirtaus

KW - lämmönsiirto

KW - turbulence

KW - computational fluid dynamics

KW - two-phase flow

KW - heat transfer

M3 - Doctoral Thesis

SN - 978-952-64-0520-9

T3 - Aalto University publication series DOCTORAL DISSERTATIONS

PB - Aalto University

ER -

Numerical studies on industrial flows

Abstrakti

Tutkimusalat

YK:n kestävän kehityksen tavoitteet

Pääsy asiakirjaan

Sormenjälki

Siteeraa tätä