Noise, Vibration, and Harshness Lab

Fully anechoic acoustic chamber – Unique highly specialized infrastructure in the Czech Republic, enabling the simulation of the free field sound conditions, which are key to the implementation of highly accurate technical experiments in terms of the mechanism of noise generation and its propagation into the environment. The uniqueness lies in the possibility of installing different types of energy machines, while the power can be supplied or braked using an active dynamometer (there is no other chamber in the Czech Republic that has an active dynamometer located externally, i.e. outside the chamber). The acoustic chamber is also dimensioned for the operation of internal combustion engines, transmission systems and powertrain assemblies or self-propelled test stands, in the entire range of operating loads (80 kW). The chamber fulfils the specification of the ISO 3745 standard in the frequency range of 100 Hz ÷ 20 000 Hz while maintaining the acoustic absorption coefficient of 0.99.

36-channel multianalyser – Analyser of vibroacoustic quantities from the Brüel & Kjaer company, represents a contemporary top in the field of equipment for recording and processing measured data. In combination with a wide range of sensors (uniaxial and triaxial accelerometers, load cells, impact hammers of various sizes, acoustic camera and intensity probe) forms a strong basis for the possible realization of technical experiments in terms of determination, modal parameters of structures (EMA, OMA, ODS) and vibroacoustic responses under the synchronous monitoring of operating parameters (angular frequency, torque, temperatures).

Acoustic camera – Highly specialized device intended for the localization of the noise sources and investigating of the propagation of acoustic waves. The accuracy of this device is strongly influenced by the quality of the acoustic environment in which the localization of noise sources is performed. For this reason, it is very appropriate to implement the infrastructure in a fully anechoic acoustic chamber.

Sound intensity field – Set of acoustic intensity probes, with a precisely given position of the sensors, which enables the localization of noise sources in the lower range of the frequency spectrum, which is typical for noise initiated based on the functional principle of machine components. 

Modal exciter – Device that enables the applying of a precisely defined excitation of structures. This device is crucial for the implementation of partial technical experiments, with the aim of material properties determining. The structure is thus exposed to excitation, which can have the form of a harmonic signal with a precisely defined frequency and force amplitude. Knowledge of these parameters is crucial for the validation of computational models.

Omnisource – This device enables the excitation of acoustic cavities. It is a certified omnidirectional sound source with precisely definable amplitude, phase and frequency of the excitation signal. The device enables technical experiments to be carried out, where the application of artificially induced acoustic noise is required to determine the parameters of acoustic cavities, such as the interiors of vehicle cabins, engine compartments and others.

Modal hammer – Tool used for testing and analysing the vibration and dynamic properties of structures. It enables the application of a controlled pulse of force to the tested object and thus to obtain its frequency response. The modal hammer is a key tool for determining modal parameters such as natural frequencies, mode shapes and damping of an object whereas knowledge of the damping of a specific object is crucial to increase the accuracy of computational models for describing the dynamic expression of components

The size of the force required for excitation depends on the size of the object being excited, which is why IAE disposes by a wider range of modal hammers with head weights from 2 g to 100 g with an excitation frequency range of up to 60 000 Hz.