The number of space structures launched into orbit is increasing rapidly, as satellites are more and more used for communication, navigation, earth monitoring and exploring other planets. During launch, these space structures are exposed to tremendous acoustic loads as induced by the launching vehicle taking off after ignition.
In order to ensure the proper functioning of the satellites and the solar panels powering them, extensive testing takes place in reverberant high intensity acoustic chambers and shaker facilities before launch. An ESA-ESTEC paper from 2003 confirms that the acoustic load during launch is one of the dimensioning cases of spacecraft structures and their payload components, especially for large antenna reflectors and solar panels. ( click to read full article ) Hence the improvement of vibro acoustic testing capabilities is crucial to the space industry.
The actual outdoor launch itself is known to be a low frequency problem but with many unknown aspects still. Quite some efforts are spent to understand where the noise sources occur in the jet plume of the exhaust during static firing testing.
For the extremely high noise levels that lie in the non linear range of acoustics, Microflown Technologies is offering special sensors that can be used for a variety of breakthrough testing methods to be applied both indoor and outdoor.
For indoor testing methods are offered for both shaker facilities and large non anechoic reverberant rooms.
Indoor testing applications include:
- non contact measurement of structural vibrations
- characterization of reverberant room global sound field
- measurement of acoustic impedance on the test object surface
- acoustic near field sound source localization
For outdoor rocket launches, testing methods are offered for both static firing testing and the monitoring of the actual full scale launch.
- acoustic vector based (low frequency) sound source localization techniques
- assessment of ground impedance
- Benifit of acoustic particle velocity based reverberant room testing of spacecraft (PDF)
Published at the IMAC 2011, E. Tijs, J. Wijker, A. Grillenbeck
- Statistical properties of kinetic and total energy densities in reverberant spaces (PDF)
Published at the JASA 2010, F. Jacobsen, A. Rodriguez Molares
- Measurement of total sound energy density in enclosures at low frequencies (PDF)
Published at the Acoustics 2008, F. Jacobsen
- A Comparison of two different sound intensity measurement principles (PDF)
Published at the JASA 2005, F. Jacobsen, H-E de Bree
- Near Field Acoustic Holography with particle velocity transducers (PDF)
Published at the JASA 118(5), 2005, Finn Jacobsen, Yang Liu
- Acoustic Source Localization based on Pressure and Particle Velocity Measurements (PDF)
Published at the Internoise 2003, R. Visser
- Obtaining the complex pressure field at the hologram surface for use in near-field acoustical holography when pressure and in-plane velocities are measured (PDF)
Published at the JASA 2005, M.C. Harris, J.D. Blotter
- Statistically optimized near field acoustic holography using an array of pressure-velocity probes (PDF)
Published at the JASA 2007, F. Jacobsen
- The very near field; theory, simulations and measurements (PDF)
Published at the ICSV11, 2004, Hans-Elias de Bree
- Experimental Modal Analysis Of Large Fuselage Panel For Composite Structure: Contact And Non-Contact Measurement (PDF)
Published at the ISMA 2008, M. Luczak, E. Pierro, E. Mucchi, A. Vecchio
- Time domain identification of loads on plate-like structures using an array of acoustic velocity sensors (PDF)
Published at the Acoustics 2008, Q. Leclere, C. Pezerat
- Measurement of sound power and absorption in reverberation chambers using energy density (PDF)
Published at the JASA, 2007, D. Nutter
- Vibroacoustic loads on spacecraft antennae: analysis and test correlation (PDF)
Published at the ESA-ESTEC & EADS CASA Espacio, 2003, J. Santiago-Prowald, G. Rodrigues, J.L. Rioboo-Estripot
- Comparison of two high intensity acoustic test facilities (PDF)
Published at the Interspace, INPE-LIT, KARI-SITC, 2004, A. Laumay, M. Sakita, Y. Kim
- Vibroacoustic loads on spacecraft: FEM/BEM simulation (PDF)
Published at the FENet workshop, 2003, J. Santiago-Prowald, G. Rodrigues, A. Calvi, T. Hendriksen
- Acoustic Source Localization: exploring theory and practice (PDF)
PhD thesis, University of Twente, 2009, Jelmer Wind
- Automotive & Ground Vehicles
- Appliances & Electronics
- Aerospace & Aviation
- End of line control
- Room Acoustics
- Environmental Noise
- MEMS Testing
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