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SUMMARY:MEchanics GAthering –MEGA- Seminar: A triple source model of pre
 ssure fluctuation analysis for a mixed-flow pump
DTSTART:20260924T123000
DTEND:20260924T133000
DTSTAMP:20260923T122150Z
UID:f430e5e39b4f762036340bd63bbc0d3ccb3fb0f91dd75b849ff0b718
CATEGORIES:Conferences - Seminars
DESCRIPTION:Bingfu Han (HEAD\, EPFL)\nAbstract: Pressure fluctuations in 
 turbomachinery arise from the combined effects of blade rotation\, coheren
 t flow instabilities and broadband turbulence\, making their physical orig
 ins difficult to isolate. This presentation introduces a triple source mod
 el for pressure fluctuations on the stationary shroud wall of a mixed-flow
  pump. The model decomposes the measured signal into a kinematic non-unifo
 rm component caused by the steady blade sweep\, a phase-locked flow-synchr
 onous component\, and a non-phase-locked flow-asynchronous component. Appl
 ied to experimentally validated stress-blended eddy simulations\, the fram
 ework shows that synchronous contributions account for more than 90% of th
 e fluctuation energy along the tip leakage vortex trajectory. It also reve
 als destructive interference between the steady pressure footprint and the
  dynamic vortex response\, with a local cross-correlation coefficient of -
 0.26. Pressure Poisson equation analysis then links each component to its 
 fluid-dynamic source: mean momentum flux drives the non-uniform pressure a
 symmetry\, periodic vortex-turbulence interaction dominates the synchronou
 s response\, and nonlinear turbulent interactions generate the broadband c
 omponent. These results identify the tip leakage vortex as the common phys
 ical nexus of the three sources. The framework provides a quantitative bas
 is for diagnosing turbomachinery unsteadiness and for developing targeted 
 strategies to reduce pressure fluctuations\, vibration and noise.\n \nBio
 graphy: Bingfu Han has been a direct-entry PhD candidate in Energy and Po
 wer Engineering at Tsinghua University\, Beijing\, China\, since 2022\, un
 der the supervision of Prof. Lei Tan. He is currently a visiting PhD resea
 rcher in the HEAD Lab at EPFL from July to October 2026\, hosted by Prof. 
 Eunok Yim. He received a bachelor's degree in Energy and Power Engineering
  from the School of Energy and Power Engineering at Xi'an Jiaotong Univers
 ity in June 2022. His research focuses on turbomachinery flow physics and 
 mechanism-aware design\, combining high-fidelity CFD\, experiments\, spect
 ral proper orthogonal decomposition\, resolvent analysis\, pressure-Poisso
 n source analysis and optimization. His work has been published in the Jou
 rnal of Fluid Mechanics\, Physics of Fluids and Ocean Engineering.
LOCATION:ME B1 10 https://plan.epfl.ch/?room==ME%20B1%2010 https://epfl.zo
 om.us/s/68096021948?pwd=DiE8amDIwYw1u3VtW2xWNGKtioKL2y.1
STATUS:CONFIRMED
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