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<front>
<journal-meta>
<journal-id journal-id-type="publisher">EGUsphere</journal-id>
<journal-title-group>
<journal-title>EGUsphere</journal-title>
<abbrev-journal-title abbrev-type="publisher">EGUsphere</abbrev-journal-title>
<abbrev-journal-title abbrev-type="nlm-ta">EGUsphere</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub"></issn>
<publisher><publisher-name>Copernicus Publications</publisher-name>
<publisher-loc>Göttingen, Germany</publisher-loc>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.5194/egusphere-2025-2328</article-id>
<title-group>
<article-title>Improving turbulent airflow direction measurements for fiber-optic distributed sensing using numerical simulations</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Abdoli</surname>
<given-names>Mohammad</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Pirkhoshghiyafeh</surname>
<given-names>Reza</given-names>
</name>
<xref ref-type="aff" rid="aff3">
<sup>3</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Thomas</surname>
<given-names>Christoph K.</given-names>
<ext-link>https://orcid.org/0000-0003-2277-6013</ext-link>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
<xref ref-type="aff" rid="aff4">
<sup>4</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Micrometeorology Group, University of Bayreuth, Universitätsstraße, 95447 Bayreuth, Bavaria, Germany</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>Physical Geography and Climatology, RWTH Aachen University, Wüllnerstraße 5b, 52062 Aachen, North Rhine-Westphalia, Germany</addr-line>
</aff>
<aff id="aff3">
<label>3</label>
<addr-line>School of Mechanical Engineering, University of Tabriz, Bahman Boulevard 29, 5165665931 Tabriz, Iran</addr-line>
</aff>
<aff id="aff4">
<label>4</label>
<addr-line>Bayreuth Center for Ecology and Environmental Research (BayCEER), University of Bayreuth, Universitätsstraße, 95447 Bayreuth, Bavaria, Germany</addr-line>
</aff>
<pub-date pub-type="epub">
<day>04</day>
<month>07</month>
<year>2025</year>
</pub-date>
<volume>2025</volume>
<fpage>1</fpage>
<lpage>21</lpage>
<permissions>
<copyright-statement>Copyright: &#x000a9; 2025 Mohammad Abdoli et al.</copyright-statement>
<copyright-year>2025</copyright-year>
<license license-type="open-access">
<license-p>This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit <ext-link ext-link-type="uri"  xlink:href="https://creativecommons.org/licenses/by/4.0/">https://creativecommons.org/licenses/by/4.0/</ext-link></license-p>
</license>
</permissions>
<self-uri xlink:href="https://egusphere.copernicus.org/preprints/2025/egusphere-2025-2328/">This article is available from https://egusphere.copernicus.org/preprints/2025/egusphere-2025-2328/</self-uri>
<self-uri xlink:href="https://egusphere.copernicus.org/preprints/2025/egusphere-2025-2328/egusphere-2025-2328.pdf">The full text article is available as a PDF file from https://egusphere.copernicus.org/preprints/2025/egusphere-2025-2328/egusphere-2025-2328.pdf</self-uri>
<abstract>
<p>This study investigates the impact of microstructure geometry on the thermal and turbulence responses of fiber-optic (FO) cables under varying flow conditions and turbulence intensities. The underlying measurement principle is the directionally sensitive heat loss from electrically heated FO cables with imprinted microstructures exposed to turbulent airflows resembling a long hot-wire anemometer. Using the COMSOL Multiphysics 6.0 finite-element software, this study explores a wider range of different configurations of filled and hollow filled-coned microstructures of varying size compared to existing studies. The research identifies optimal combinations which maximize temperature differences (∆&lt;em&gt;T&lt;/em&gt;) across FO cables with cones pointing in opposite directions while balancing key design criteria such as sensitivity to wind speed and minimizing the cables&amp;rsquo; PVC coverage. We demonstrate that FO cables with hollow-coned microstructures (&lt;em&gt;radius&lt;/em&gt; = 24 mm, &lt;em&gt;height&lt;/em&gt; = 24 mm, and &lt;em&gt;spacing&lt;/em&gt; = 15 mm) outperform their filled-coned counterparts, maintaining ∆&lt;em&gt;T&lt;/em&gt; values above 2 K across a broader range of wind speeds and turbulence intensities. Notably, the hollow-cone configuration sustains a temperature difference of up to 0.8 K at a 60(&amp;deg;) wind attack angle. The findings implicate substantial improvements for an optimized FO cable design in atmospheric boundary layer studies, enabling more accurate measurements of wind direction, distributed turbulent heat fluxes, and vertical wind speed perturbations using fiber-optic distributed sensing (FODS). Future work shall validate the findings under field conditions to assess the robustness and real-world applicability of the optimized design.</p>
</abstract>
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<funding-group>
<award-group id="gs1">
<funding-source>European Research Council</funding-source>
<award-id>724629</award-id>
</award-group>
</funding-group>
</article-meta>
</front>
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