{"id":2061,"date":"2026-04-29T18:40:30","date_gmt":"2026-04-29T18:40:30","guid":{"rendered":"https:\/\/hydroalpslab.ch\/?p=2061"},"modified":"2026-04-30T05:45:56","modified_gmt":"2026-04-30T05:45:56","slug":"hydro-alps-lab-refines-part-load-flare-mapping-with-european-revhydro-project","status":"publish","type":"post","link":"https:\/\/hydroalpslab.ch\/en\/le-hydro-alps-lab-affine-la-cartographie-du-la-torche-a-charge-partielle-avec-le-projet-europeen-revhydro\/","title":{"rendered":"Hydro Alps Lab refines part-load flare mapping with European ReVHydro project"},"content":{"rendered":"<p>Last week, at the technical meeting of the European consortium <a href=\"https:\/\/revhydro.eu\/\" target=\"_blank\" rel=\"noopener\">ReVHydro<\/a> held in Sion, Francesco Lagravinese, a doctoral student at the Hydro Alps Lab, presented a major advance in our understanding of partial-load instabilities. His work addresses a major challenge: how to accurately detect and predict the Rotating Vortex Rope (RVR) without exploding numerical computation costs?<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img fetchpriority=\"high\" decoding=\"async\" width=\"1024\" height=\"682\" src=\"https:\/\/hydroalpslab.ch\/wp-content\/uploads\/2026\/04\/RevHydro-meeting-16.04.2026-\u00a9dab-02_1-1024x682.jpg\" alt=\"\" class=\"wp-image-2068\" srcset=\"https:\/\/hydroalpslab.ch\/wp-content\/uploads\/2026\/04\/RevHydro-meeting-16.04.2026-\u00a9dab-02_1-1024x682.jpg 1024w, https:\/\/hydroalpslab.ch\/wp-content\/uploads\/2026\/04\/RevHydro-meeting-16.04.2026-\u00a9dab-02_1-300x200.jpg 300w, https:\/\/hydroalpslab.ch\/wp-content\/uploads\/2026\/04\/RevHydro-meeting-16.04.2026-\u00a9dab-02_1-768x512.jpg 768w, https:\/\/hydroalpslab.ch\/wp-content\/uploads\/2026\/04\/RevHydro-meeting-16.04.2026-\u00a9dab-02_1-1536x1023.jpg 1536w, https:\/\/hydroalpslab.ch\/wp-content\/uploads\/2026\/04\/RevHydro-meeting-16.04.2026-\u00a9dab-02_1-2048x1364.jpg 2048w, https:\/\/hydroalpslab.ch\/wp-content\/uploads\/2026\/04\/RevHydro-meeting-16.04.2026-\u00a9dab-02_1-18x12.jpg 18w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p><strong>Predicting the \u00abtorch\u00bb without overloading supercomputers<\/strong><\/p>\n\n\n\n<p>RVR is the vortex that appears at the impeller outlet when the turbine is operating outside its optimum efficiency point at partial load. If poorly controlled, it generates severe pressure pulsations that prematurely fatigue the structure. Francesco outlined a game-changing strategy for rationalising costs:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Optimised CFD methodology: instead of using time-consuming simulations, it has proved that a coarser mesh and a less restrictive time step can reliably detect pressure fluctuations linked to the RVR.<\/li>\n\n\n\n<li>Mapping the efficiency \u00abhill\u00bb: this work has enabled us to isolate precisely the critical \u00abRVR max\u00bb region on a matrix of 9 operating points (combining different guide openings and specific speeds).<\/li>\n\n\n\n<li>Experimental validation: this numerical approach has been validated by real pressure measurements carried out in the laboratory by GE Vernova, confirming that the model perfectly follows the observed physical behaviour.<\/li>\n<\/ul>\n\n\n\n<p><strong>A springboard for IAHR 2026 <\/strong><\/p>\n\n\n\n<p>These results are just the first step. By effectively mapping this critical zone, Francesco Lagravinese is laying the foundations for the development of control systems to mitigate the RVR and for the creation of Reduced Order Models (ROMs). For the Lab's partners, in particular GE Vernova and the team led by Prof. Michel Cervantes from the University of Lule\u00e5 (LTU), involved in this part of the project, this breakthrough offers a concrete way of improving the flexibility of existing turbines while simplifying the numerical optimisation phases. This work will be presented in greater detail this autumn at the\u2019<a href=\"https:\/\/iahr2026.unifei.edu.br\/\" target=\"_blank\" rel=\"noopener\">IAHR 2026<\/a> in Igua\u00e7u.<\/p>\n\n\n\n<figure class=\"wp-block-video\"><video height=\"720\" style=\"aspect-ratio: 1280 \/ 720;\" width=\"1280\" controls src=\"https:\/\/hydroalpslab.ch\/wp-content\/uploads\/2026\/04\/film_torche_Francesco.mp4\"><\/video><\/figure>\n\n\n\n<p><\/p>","protected":false},"excerpt":{"rendered":"<p>La semaine derni\u00e8re, lors du meeting technique du consortium europ\u00e9en ReVHydro organis\u00e9 \u00e4 Sion, Francesco Lagravinese, doctorant au Hydro Alps Lab, a pr\u00e9sent\u00e9 une avanc\u00e9e majeure pour la compr\u00e9hension des instabilit\u00e9s en charge partielle. Son travail porte sur un d\u00e9fi de taille : comment d\u00e9tecter et pr\u00e9dire avec pr\u00e9cision la \u00ab\u00a0torche\u00a0\u00bb (Rotating Vortex Rope &#8211; [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":2064,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[11],"tags":[],"class_list":["post-2061","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-actualite"],"_links":{"self":[{"href":"https:\/\/hydroalpslab.ch\/en\/wp-json\/wp\/v2\/posts\/2061","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/hydroalpslab.ch\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/hydroalpslab.ch\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/hydroalpslab.ch\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/hydroalpslab.ch\/en\/wp-json\/wp\/v2\/comments?post=2061"}],"version-history":[{"count":7,"href":"https:\/\/hydroalpslab.ch\/en\/wp-json\/wp\/v2\/posts\/2061\/revisions"}],"predecessor-version":[{"id":2074,"href":"https:\/\/hydroalpslab.ch\/en\/wp-json\/wp\/v2\/posts\/2061\/revisions\/2074"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/hydroalpslab.ch\/en\/wp-json\/wp\/v2\/media\/2064"}],"wp:attachment":[{"href":"https:\/\/hydroalpslab.ch\/en\/wp-json\/wp\/v2\/media?parent=2061"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/hydroalpslab.ch\/en\/wp-json\/wp\/v2\/categories?post=2061"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/hydroalpslab.ch\/en\/wp-json\/wp\/v2\/tags?post=2061"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}