DEA - Dynamical Energy Analysis

Ship with engine excitation. Plate radiation levels (color scheme) and cavity noise levels (blue).

A new product to solve your vibro-acoustic problems across the whole frequency range!

Motivation

Predicting wave energy distributions for short-wavelength vibrations, elastic deformations or acoustic radiation in complex built-up structures is a challenging task. An efficient, reliable and universal algorithm is now available based on a new technique called Dynamical Energy Analysis (DEA) covering the mid-to-high frequency range.

Advantages of DEA

• can be based on existing FEM meshes. No new modelling effort.
• closes the midfrequency gap, where FEM is too expensive and the underlying assumptions of SEA do not apply.
• more efficient than ray tracing.
• offers information about spatial resolution within each subsystem in contrast to SEA's average per subsystem.
• the mesh size can be chosen independently of the frequency and coarser than in FEM. It only needs to resolve the geometry.
• computational time is independent of the frequency. In contrast to FEM, high frequencies are even a bit faster due to stronger damping.

Shock tower of a car. Comparison between FEM frequency averaged and DEA result.

Application

• sound and vibration propagation in mechanical structures (Ships, Trains, Airplanes, Trucks, Cars, Buildings, ...).
• general complex built-up structures in mechanical engineering.
• acoustics in buildings.
• electromagnetic waves (microwave, optics, RF fields, WiFi, etc.).

Features

• Nastran and Ansys meshes can be imported.
• handles any 3d structure that consists of (2d) plates (with polygonal boundary).
• ray based method with directionality (SEA does not).
• interpolates between SEA and ray tracing.

The graphical user interface of the DEA software. Parameter setting on the left and the geometry displayed on the right side.
• arbitrary number of wave modes supported, i.e. bending, pressure and shear wave. Mode coupling and reflection, transmission and refraction at interfaces is computed via local solutions of the full wave equation.
• boundary conditions can range from full reflection to full transparency or even external flux.
• Sound sources can be applied on the structure or in the surrounding air or water (e.g. propeller).
• solution can be evaluated in any position. Automatic grid generation and export of result for 3d visualisation.
• average sound level per plate can be computed.
• sound package damping for sound sources and noise level in rooms.
• cavity functionality to get the sound level in each room. This includes noise transmission through walls, windows, air ducts, ...
• single and multiprocessor operation mode

Getting the Simulation Tool

For more information and to order the product, please contact us at dea@inutech.de.

Origin of the method

The core of the DEA method originates from research results of Gregor Tanner, associate professor at the School of Mathematical Sciences, University of Nottingham. Within the EU project MiDEA, the academical results have been implemented into software and since then have been extended for practical use by InuTech GmbH.

Discrete Flow Mapping DFM

The term DEA describes the method in general. The term DFM (Discrete Flow Mapping) is used in science for the specific software implementation of DEA on triangulated meshes. Triangulated meshes are a too strong restriction in industrial applications. Therefore, inuTech implements an extended version of DFM that is capable to treat quadrilateral and any convex polygonal elements. Thus, finite element meshes (FEM) are fully supported.

Abbreviations

• DEA — Dynamical Energy Analysis
• DFM — Discrete Flow Mapping
• FEM — Finite Element Method
• SEA — Statistical Energy Analysis