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dc.contributor.advisorVirk, Muhammad
dc.contributor.authorSokolov, Pavlo
dc.date.accessioned2021-08-17T10:05:59Z
dc.date.available2021-08-17T10:05:59Z
dc.date.issued2021-08-31
dc.description.abstractThe study of the atmospheric ice accretion has received some attention from the scientific community in the past, with the available knowledge spanning from the works of the Langmuir and Blodgett (1946) on the Mt. Washington Observatory till the analytical parameterization of the Finstad et al. (1988), with the latter being the current analytical benchmark and the integral part of the ISO 12494 “Atmospheric Icing on Structures”, which serves as a current guideline for the analytical estimation of the ice loads on structures. One of the major limitations of the Finstad et al. parameterization is its applicability for the range of the overall collision efficiencies of 0.07 < E < 0.63, resulting from the experimental verification by Makkonen and Stallabrass (1987). Furthermore, ISO 12494 standard states that the current model underestimates the accreted ice masses for the collision efficiencies values below E < 0.10 and the Finstad et al. themselves postulate that they consider the lower limit of droplet inertia parameter being K = 0.25 in their model. Below this limit Finstad et al. advise to “recalculate the droplet trajectories using the appropriate drag coefficients for each droplet size in the spectra”. As evidenced by the available data from the test span measurements at the Ålvikfjellet test span in Norway, the majority of the extreme ice loads occur for the value of K below the critical value of 0.25. Thus, there is a need for a method which allows for better prediction and estimation of ice loads for such conditions, with one of the primary applications being modeling of extreme value loads on the overhead power lines for the purposes of the ice maps generation and ice load guidelines. However, the calculation of the “history” term, which is a non-steady state drag coefficient, which needs, ideally, to be taken into account in the modeling of the atmospheric ice accretion for the cases when K < 0.25 is rather challenging, with the issues pertaining to it and some possible solutions being reviewed within the scope of this thesis. Instead, the usage of the “idealized” Langmuir distributions is suggested, those originally proposed by Langmuir and Blodgett (1946) and Howe (1990). Those distributions have the same values of the Median Volume Diameter (MVD) as the typically postulated assumption of the monodispersed distribution from the ISO 12494, which makes them suitable under the framework.en_US
dc.description.doctoraltypeph.d.en_US
dc.description.popularabstractThe study of the atmospheric ice accretion is an established scientific field, with the available knowledge spanning from the works of the Langmuir and Blodgett till Finstad et al., with latter being the current analytical benchmark and the integral part of the ISO 12494 “Atmospheric Icing on Structures”, a current guideline for the estimation of the ice loads on structures. One of the major limitations of the Finstad et al. parameterization is its applicability for the range of Stokes number, K > 0.25. From the available data from the measurements at the Ålvikfjellet test span in Norway, the majority of the extreme ice loads occur for the value of K ≤ 0.25. There is a need for better prediction and estimation of ice loads for such cases, with the applications of modeling of extreme loads on the overhead power lines, the ice maps generation and ice load guidelines. The use of the “idealized” Langmuir distributions is suggested, originally proposed by Langmuir and Blodgett and Howe.en_US
dc.description.sponsorshipResearch Council of Norway, FRonTLINES- project no. 245370 & IceBOX- project no 282403.en_US
dc.identifier.isbn978-82-7823-229-3
dc.identifier.isbn978-82-7823-230-9
dc.identifier.urihttps://hdl.handle.net/10037/22088
dc.language.isoengen_US
dc.publisherUiT Norges arktiske universiteten_US
dc.publisherUiT The Arctic University of Norwayen_US
dc.relation.haspart<p>Paper 1: Sokolov, P. & Virk, M.S. (2018). Analytical Parametrizations of Droplet Collision Efficiency on Cylinders – a Review Study. <i>Cold Regions Science and Technology, 155</i>, 119 – 127. Also available at <a href=https://doi.org/10.1016/j.coldregions.2018.08.015>https://doi.org/10.1016/j.coldregions.2018.08.015</a>. <p>Paper 2: Sokolov, P. & Virk, M.S. (2019). Droplet Distribution Spectrum Effects on Dry Ice Growth on Cylinders. <I>Cold Regions Science and Technology, 160</i>, 80 – 85. Also available at <a href=https://doi.org/10.1016/j.coldregions.2019.01.002>https://doi.org/10.1016/j.coldregions.2019.01.002</a>. Accepted manuscript version available in Munin at <a href=https://hdl.handle.net/10037/16610>https://hdl.handle.net/10037/16610</a>. <p>Paper 3: Sokolov, P. & Virk, M.S. (2020). An investigation into empirical ice density formulations for dry ice growth on cylinders. <i>Cold Regions Science and Technology, 169</i>, 102906. Also available at <a href=https://doi.org/10.1016/j.coldregions.2019.102906>https://doi.org/10.1016/j.coldregions.2019.102906</a>. Accepted manuscript version available in Munin at <a href=https://hdl.handle.net/10037/17817>https://hdl.handle.net/10037/17817</a>. <p>Paper 4: Sokolov, P., Jin, J.Y. & Virk, M.S. (2019). Accreted Ice Mass Ratio (k–factor) for Rotating Wind Turbine Blade Profile and Circular Cylinder. <I>Wind Energy, 22</i>, 447 – 457. Also available at <a href=https://doi.org/10.1002/we.2298>https://doi.org/10.1002/we.2298</a>. <p>Paper 5: Sokolov, P. & Virk, M.S. (2019). Modeling of Dry Ice Accretion on Cylinders – A Case Study of Present Analytical State. <i>Proceedings – 18th Int. Workshop on Atmospheric Icing of Structures, 2019, IWAIS 2019 - Reykjavík, June 23 – 28</i>. Also available at <a href=https://iwais2019.is/images/Papers/055_iwais-sokolov-virk.pdf> https://iwais2019.is/images/Papers/055_iwais-sokolov-virk.pdf</a>. <p>Paper 6: Sokolov, P. & Virk, M.S. (2020). Aerodynamic Forces on Iced Cylinder for Dry Ice Accretion – A Numerical Study. <i>Journal of Wind Engineering & Industrial Aerodynamics, 206</i>, 104365. Also available in Munin at <a href=https://hdl.handle.net/10037/22086>https://hdl.handle.net/10037/22086</a>. <p>Paper 7: Sokolov, P. & Virk, M.S. Study of Dry Ice Growth on Duplex Cylinders. (Submitted manuscript).en_US
dc.relation.projectIDinfo:eu-repo/grantAgreement/RCN/ENERGIX/245370/Norway/Development of a toolbox for assessing Frost and Rime ice impact on overhead Transmission Lines/FRonTLINES/en_US
dc.relation.projectIDinfo:eu-repo/grantAgreement/RCN/ENERGIX/282403/Norway/Ice monitoring, forecasting, mapping, prevention and removal toolbox/IceBOX/en_US
dc.rights.accessRightsopenAccessen_US
dc.rights.holderCopyright 2021 The Author(s)
dc.rights.urihttps://creativecommons.org/licenses/by-nc-sa/4.0en_US
dc.rightsAttribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)en_US
dc.subjectVDP::Mathematics and natural science: 400::Mathematics: 410::Applied mathematics: 413en_US
dc.subjectVDP::Matematikk og Naturvitenskap: 400::Matematikk: 410::Anvendt matematikk: 413en_US
dc.titleStudy of the in-cloud dry ice accretion on cylinders for low values of the Stokes numberen_US
dc.typeDoctoral thesisen_US
dc.typeDoktorgradsavhandlingen_US


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