Abstract
The authors have developed an acoustic model of a lift,
using a multi-disciplinary
approach. The model enables a full understanding of how
the lift design is affected by noise
requirements inside the car, and in buildings that are
still in planning or construction phase. The
approach is based on a hybrid model combining structural
finite element (FEM); computational fluid
dynamics (CFD); boundary element method (BEM) and
statistical energy analysis (SEA); to cover
both low and relatively high frequency acoustical domains
in a sufficiently detailed model with a
reasonable computational time. Special attention has been
paid to modelling of the noise sources.
Structure-borne sources (point forces) due to roller
guide shoes and ropes were applied on the system.
Forces were determined on grounds of FEM-computed point
mobilities and measured vibration
velocity responses at the same excitation points.
Airborne sources due to flow-induced noise were
computed using an incompressible transient CFD analysis.
The resulting time variable air surface
pressure was then applied on the car walls. The surface
pressure spectra were used both directly (the
convective source) and as a source for the acoustic
propagation (giving the acoustic source). The
reverberant sound field in the hoistway, generated by the
flow sources, is a significant contributor.
This part was modelled using BEM. The time variable
pressure field on the car surface was used as
a source distribution for BEM. The end result of the
computation was applied as a diffuse acoustic
field on the car surfaces. All the sources:
structure-borne and airborne, were applied as forces and
pressures. They were internally converted to power inputs
for solving the SEA model. All transfer
paths in the sling, car, doors, fairings and hoistway,
including relevant leaks were simulated. After
validation, the hybrid model now allows the users to
quantify and rank noise contribution of each
source and make predictions based on changes in the lift
structure, hoistway design and car running
parameters.
Original language | English |
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Title of host publication | Proceedings of the 7th Symposium on Lift & Escalator Technologies |
Number of pages | 10 |
Publication status | Published - 2017 |
MoE publication type | A4 Article in a conference publication |
Event | 7th Symposium on Lift and Escalator Technologies - Northampton, United Kingdom Duration: 20 Sep 2017 → 21 Sep 2017 |
Conference
Conference | 7th Symposium on Lift and Escalator Technologies |
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Country | United Kingdom |
City | Northampton |
Period | 20/09/17 → 21/09/17 |
Keywords
- aero-vibro-acoustics
- lifts
- high speed
- high rise
- FEM
- BEM
- CFD
- SEA