BEGIN:VCALENDAR VERSION:2.0 PRODID:-//wp-events-plugin.com//6.6.4.4//EN TZID:Asia/Jerusalem X-WR-TIMEZONE:Asia/Jerusalem BEGIN:VEVENT UID:0-1523@aerospace.technion.ac.il DTSTART;TZID=Asia/Jerusalem:20260114T133000 DTEND;TZID=Asia/Jerusalem:20260114T143000 DTSTAMP:20251222T133249Z URL:https://aerospace.technion.ac.il/events/seminar-slot-2026-01-14/ SUMMARY:Morphology-Controlled Sheet Spray Cooling from Convergent Micronozz les for Hypersonic Leading Edges DESCRIPTION:Lecturer:Alexandros Peteinaris\n Faculty:The Stephen B. Klein F aculty of Aerospace Engineering at the Technion \n Institute:Technion – Israel Institute of Technology\n Location:Classroom 165\, ground floor\, L ibrary\, Aerospace Eng.\n Zoom: https://technion.zoom.us/j/93549691766\n A bstract: Thermal management for hypersonic leading edges must remove extre me heat fluxes within ultra-thin\, aerodynamically constrained structures\ , where passive approaches are limited by available volume and surface-tem perature margins. This study experimentally investigates convergent micro- nozzle sheet sprays as an active cooling concept for leading-edge integrat ion. The goal is to combine minimal coolant thickness and consumption with strong near-wall renewal and mixing.\nLiquid sheets are generated using l ithographically fabricated micronozzles and characterized via high-speed s hadowgraph imaging to quantify breakup and atomization pathways. The measu rements show that increasing the flow rate and outlet confinement expand t he sheet size and extend the stable-sheet region. In contrast\, the conver gent angle systematically reshapes the sheet by redistributing momentum at the nozzle exit. A scaling analysis predicts stable-sheet dimensions and is used to construct a Weber-number-convergent angle-regime map that class ifies the observed sheet morphologies.\nDownstream atomization is quantifi ed using laser diffraction\, which reveals single-peak and bimodal droplet -size distributions associated with specific regimes and highlights the st rong influence of the outlet aspect ratio on mean droplet diameters. Stead y-state infrared thermography provides spatially resolved heat-transfer co efficient maps\, directly linking spray structure to cooling performance. For the conditions tested\, more coherent\, planar sprays provide higher a rea-averaged cooling than fully atomized sheets. However\, targeted regime selection and local morphological manipulation can enhance peak heat tran sfer at the leading edge\, where it is most needed. These results provide experimentally grounded design rules for micro-nozzle geometry and flow ra te to tailor cooling footprints for hypersonic thermal protection.\n\n&nbs p\;\n\n \;\n\n \;\n\n \;\n Details: \n CATEGORIES:Seminars,סמינרים LOCATION:Classroom 165\, ground floor\, Library\, Aerospace Eng. END:VEVENT BEGIN:VTIMEZONE TZID:Asia/Jerusalem X-LIC-LOCATION:Asia/Jerusalem BEGIN:STANDARD DTSTART:20251026T010000 TZOFFSETFROM:+0300 TZOFFSETTO:+0200 TZNAME:IST END:STANDARD END:VTIMEZONE END:VCALENDAR