bei Google ScholarTitelangaben
Ghodbene, Maroua ; Auer, Henry ; Franzke, Christopher ; Maaß, Jochen ; Moos, Ralf:
Flow Regime Analysis of Slit Nozzle Operating Conditions under Vacuum Using CFD and Optical Diagnostics for Powder Aerosol Deposition.
2026
Veranstaltung: ILASS Europe 2026, 34th Conference on Liquid Atomization & Spray Systems
, 6th - 9th Sept. 2026
, Lisbon, Portugal.
(Veranstaltungsbeitrag: Kongress/Konferenz/Symposium/Tagung
,
Vortrag
)
Abstract
Powder Aerosol Deposition (PAD) enables the fabrication of dense ceramic coatings with micrometr cale thickness at room temperature by accelerating ceramic particles in a carrier gas jet and consolidating them on a substrate via kinetic impact. The nozzle operating point critically governs jet stability, particle acceleration, and deposition uniformity; however, suitable operating conditions are still selected empirically, with limited validation via compressible flow physics. In this work, the flow jet of a convergent slit nozzle with an outlet area of approximately 0.5 x 10 mm² used in PAD is investigated using a combined experimental–numerical approach. Particle Image Velocimetry (PIV), Schlieren imaging and three-dimensional compressible CFD simulations of gas and gas–particle flow investigates the formation of distinct flow regimes. While PAD is commonly operated at very low chamber pressures below 10 mbar, the present study investigates a broader parameter space, covering chamber pressures from 1 to 100 mbar, normalized volumetric flow rates from 1 to 100 NL min⁻¹, and nozzle pressure ratio (NPR) values between 5 and approximately 150. The simulations reveal two distinct jet flow regimes, ranging from strongly underexpanded jets with pronounced shock cell structures at high NPR values (≳ 40) to near-ideally expanded flows at lower NPR (≲ 30). Schlieren imaging confirms the predicted expansion and shock structures, while PIV provides quantitative axial and radial velocity distributions, enabling a physically grounded classification. The analysis demonstrates that stable particle transport and film formation in PAD are associated with specific combinations of chamber pressure, and volumetric flow rate, defining characteristic nozzle operating regimes.
Weitere Angaben
| Publikationsform: | Veranstaltungsbeitrag (Vortrag) |
|---|---|
| Begutachteter Beitrag: | Ja |
| Institutionen der Universität: | Fakultäten > Fakultät für Ingenieurwissenschaften Fakultäten > Fakultät für Ingenieurwissenschaften > Lehrstuhl Funktionsmaterialien > Lehrstuhl Funktionsmaterialien - Univ.-Prof. Dr.-Ing. Ralf Moos Profilfelder > Advanced Fields > Neue Materialien Forschungseinrichtungen > Zentrale wissenschaftliche Einrichtungen > Bayreuther Materialzentrum - BayMAT |
| Titel an der UBT entstanden: | Ja |
| Themengebiete aus DDC: | 600 Technik, Medizin, angewandte Wissenschaften > 620 Ingenieurwissenschaften |
| Eingestellt am: | 15 Okt 2026 08:11 |
| Letzte Änderung: | 15 Okt 2026 08:11 |
| URI: | https://eref.uni-bayreuth.de/id/eprint/99727 |