| |
Fabio Barone, Franca Carena, Paolo Durello, Denso Thermal Systems S.p.A,
Italy
Denso Thermal Systems
(formerly Magneti Marelli Climatizzazione) have been
using STAR-CD since 1996. As experience within the
CAE group has grown with STAR-CD, so our experimental
testing and prototyping procedures have been greatly
optimized. The CAE group continues to develop its
use and knowledge of CFD in order to provide the
best service to our customers.
One of our, and our clients', key objectives is
the reduction of flow noise produced in HVAC components.
To this end, Denso Thermal Systems has, and continues
to be, an active partner in the collaborative DESTINY
(Detached Eddy Simulation in the Transport IndustrY,
a consortium of companies, headed by CD-adapco, progressing
the knowledge of predictive aeroacoustic techniques
in an industrial framework) projects, to realize
our goal of a computational methodology to simulate
aero acoustic noise sources and their propagation.
The modeling strategy employs the LES-type turbulence
model DES, as proposed by Spalart [1], for solving
the aero acoustic sources. STAR-CD is then coupled
to an acoustic code, where these sources are propagated
to the far field.
 The
test case investigated by Denso Thermal Systems was
a centrifugal fan, as depicted in figure 1. This
problem is non-trivial in that it involves complex
geometries and flow physics; requiring meshing of
a detailed geometry, running a transient setup with
DES and mesh motion, with acoustic computations,
compared with experimental data. We generated two
meshes, both approximately 1.5 million hexahedral
cells; one with trimmed cells (proam) and the other
was entirely hexahedral. The CFD results from both
meshes were compared with experimental LDA measurements
and good agreement was achieved.
Data output from the CFD simulation, in the form
of time-varying forces on an individual fan blade
(which is considered representative), were exported
to the Computational Acoustics (CA) code, SYSNOISE.
From these forces, equivalent acoustic sources are
generated and propagated to observer locations. The
simulation gave encouraging qualitative and quantitive
Sound Pressure Level (SPL) distributions. The acoustic
radiation is slightly over predicted at the outlet,
attributed to the fact that the filter at the outlet
of the blower was not taken into account in the acoustic
computation. For further details see [2].
Denso Thermal Systems are committed, in conjunction
with CD-adapco, to continue to improve the efficiency
and accuracy of this methodology to promote greater
understanding of the complex multi-physics of AeroAcoustics.
[1] - SPALART, P.R, JOU, W.H.,
STRELETS, M. AND ALLMARAS, S.R., "Comments on
the Feasibility of LES for Wings, and on a Hybrid
RANS/LES Approach", First AFOSR International
Conference on DNA/LES, Ruston, Louisiana, USA. 1997
[2] - M. TOURNOUR, Z. EL ACHEMI,
A. READ , F. MENDONCA, FABIO BARONE , PAOLO DURELLO, " Investigation
of the tonal noise radiated by subsonic fans using
the aero-acoustic analogy", Fan Noise Conference
2003, Senlis, France 2003
|
|
Your route to this page:
