AERO_2_General_Organization-ACTRAN气动声学设置

The Th other th components t are very similar i il t to a standard acoustic analysis with ACTRAN :
ACOUSTIC and INFINITE components FLUID material …
ACTRAN General Organization Theory ACTRAN Acoustic Simulation Theory of Aeroacoustic Simulations
This presentation introduces the computational sequence involved in an ACTRAN Aeroacoustic analysis y The different steps are described:
Syntax y in the ACTRAN input p file:
BEGIN LIGHTHILL_VOLUME id DOMAIN VolLighthill FIELD field_id END LIGHTHILL_VOLUME id Domain of application BC Block ID Field identifier, for space variation
LIGHTHILL_VOLUME LIGHTHILL_SURFACE MOHRING_VOLUME MOHRING SURFACE MOHRING_SURFACE POINT_LOAD for a Pressure Wall Fluctuation on a structure surface
Acoustics
CFD solution l ti
, vi or p
Acoustic radiation
ACTRAN C ICFD C is s the e link be between ee C CFD results esu s a and d the e acous acoustic c computation
Definition in ACTRAN VI
BEGIN FIELD id FIELD_NDIM 1 RESULT_FILE NFF datase_name.nff END PRESSURE id Dimension of the Field is 1 because the sources are integrated on the mesh (scalar) The RESULT_FILE is a NFF data base and is output by ACTRAN ICFD
4
Copyright Free Field Technologies
Modeling Strategies
HVAC duct
Illustration of an aeroacoustics analysis y with ACTRAN
CAD M Model d l
0.2m 0.04m
Acoustic Mesh Acoustic fluid where sources are computed d (V (Volume l BC) Interface betw Field Technologies
The MOHRING_SURFACE _ Boundary y Condition
Syntax y in the ACTRAN input p file:
BEGIN MOHRING_SURFACE id DOMAIN SurfMohring FIELD field_id END MOHRING_SURFACE id Domain of application BC Block ID Field identifier, for space variation
Definition in ACTRAN VI
BEGIN FIELD id FIELD_NDIM 1 RESULT_FILE NFF datase_name.nff END PRESSURE id Dimension of the Field is 1 because the sources are integrated on the mesh (scalar) The RESULT_FILE is a NFF data base and is output by ACTRAN ICFD
Fan Noise
Aeroacoustics analysis y
Flow direction
CAD Model
Inlet surface f
95 mm 150 mm
Outlet surface
100 mm 83 mm
CFD Mesh Acoustic Mesh
6
Copyright Free Field Technologies
ACTRAN Aeroacoustics - General Organization g
ACTRAN Training g - AERO
Copyright Free Field Technologies
Introduction
Pre-requisites q - before g going g through g this p presentation, , the reader should have read and understood the following presentations:
10
Copyright Free Field Technologies
The MOHRING_VOLUME _ Boundary y Condition
Syntax y in the ACTRAN input p file:
BEGIN MOHRING_VOLUME id DOMAIN VolMohring FIELD field_id END MOHRING_VOLUME id Domain of application BC Block ID Field identifier, for space variation
2D Elements in Group 3
3D Elements in Group 2 Acoustic fluid for pure propagation 5 3D El Elements t i in Group 1
Copyright Free Field Technologies
Modeling Strategy
AeroAcoustic Analysis y Setup p
Pre-processing p g within ACTRAN VI & Syntax y Overview
Copyright Free Field Technologies
Acoustic Analysis y
The boundary y conditions specific p to an aeroacoustics analysis are:
9
Copyright Free Field Technologies
The LIGHTHILL_SURFACE _ Boundary y Condition
Syntax y in the ACTRAN input p file:
BEGIN LIGHTHILL_SURFACE id DOMAIN SurfLighthill FIELD field_id END LIGHTHILL_SURFACE id Domain of application BC Block ID Field identifier, for space variation
12
Copyright Free Field Technologies
The POINT_LOAD Boundary y Condition
Syntax y in the ACTRAN input p file:
BEGIN POINT_LOAD id DOMAIN pload FIELD field_id END POINT_LOAD id Domain of application BC Block ID Field identifier, for space variation
Definition in ACTRAN VI
BEGIN FIELD id FIELD_NDIM 1 RESULT_FILE NFF datase_name.nff END PRESSURE id Dimension of the Field is 1 because the sources are integrated on the mesh (scalar) The RESULT_FILE is a NFF data base and is output by ACTRAN ICFD
Content
Introduction Computational C t ti lP Process O Overview i Modeling Examples ACTRAN Aerocoustic Analysis ACTRAN ICFD Utility : the CFD/ACTRAN Interface
Definition in ACTRAN VI
BEGIN FIELD id FIELD_NDIM 3 RESULT_FILE NFF datase_name.nff END PRESSURE id The point load quantity is a vector. The dimension of the Field is the dimension of the problem (3 for 3D analyses, analyses 2 for 2D analyses) The RESULT_FILE is a NFF data base and is Copyright Free Field Technologies 13 output by ACTRAN ICFD
Definition in ACTRAN VI
BEGIN FIELD id FIELD_NDIM 1 RESULT_FILE NFF datase_name.nff END PRESSURE id Dimension of the Field is 1 because the sources are integrated on the mesh (scalar) The RESULT_FILE is a NFF data base and is output by ACTRAN ICFD
1. Acoustic analysis settings – ACTRAN VI 2. Sources computation/integration – ACTRAN ICFD 3. Acoustic propagation and post-processing – ACTRAN and ACTRAN VI
3
Copyright Free Field Technologies
Computational p Process Overview
Fluid Dynamics
CAD Model CFD Mesh M h+S Set-up t CFD computation ACTRAN ICFD Source computation Mapping + Fourier Transform ACTRAN simulation Acoustic Mesh + Setup
The computation of the sources/excitations extracted from CFD results is performed
8
using the ACTRAN ICFD utility Copyright Free Field Technologies
The LIGHTHILL_VOLUME _ Boundary y Condition
The modeling strategies for some typical applications are discussed Recommendations and guidelines are also provided
2
Copyright Free Field Technologies