Absorption of Sound by Porous Materials

Kühl, Viktor; Meyer, Erwin

doi:10.1038/130580b0

Cited by 6 publications

(3 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The ctene rows are on ridges extending the entire body length. Fishing and feeding behaviour is similar to that described for Pleurohrachia, another cydippid, by Kuhl (1932). The average swimming velocity of Mertensia was 233 m h + 104.2 (n = 20) with a high correlation with body length (r = 0.58; two-tailed Ttest, T = 3.015, p < 0.05; Fig.…”

Section: Resultssupporting

confidence: 72%

Swimming movements of ctenophores, and the mechanics of propulsion by ctene rows

Matsumoto

1991

Hydrobiologia

View full text Add to dashboard Cite

This study focuses on the mechanics of ciliary movement of ctenophores in relation to locomotion and feeding, with field and laboratory observations documented with 35 mm photographs and video sequences. Movement through the water is strongly modified by subtleties of body morphology. Whereas the entire ctenophore moves in a flow regime where the Reynolds numbers range from 100 to 6000, the cilia on the surface of the ctenophores move in a flow regime where the Reynolds numbers range only from 10 to 300. The water flow patterns seen by use of fluorescein dye do not match any current model of ciliary flow and assumptions for a new model are postulated. Ctenophores exhibit a wide variety of morphological adaptations that reduce drag, and movements for prey capture.

show abstract

Section: Resultssupporting

confidence: 72%

Swimming movements of ctenophores, and the mechanics of propulsion by ctene rows

Matsumoto

1991

Hydrobiologia

View full text Add to dashboard Cite

show abstract

“…An wissenschaftlichen Publikationen erschienen 1932 Arbeiten von Meyer zu den akustischen Eigenschaften von Holz [36] und Flachglas [37], zur Geräuschemission von Kraftfahrzeugen [38], zur Winkel-und Frequenzabhängigkeit der Schallabsorption poröser Stoffe [39,40] und zur magnetischen Schallaufzeichnung [41]. Weiterhin hielt MeyerÜberblicksvorträge zur elektroakustischen Messtechnik [42,43].…”

Section: Berlinunclassified

Erwin Meyer

Guicking¹

2012

View full text Add to dashboard Cite

(1899-1972) gilt als der führende deutsche Akustiker seiner Zeit. Er war ungewöhnlich vielseitig interessiert. Zu vielen Teilgebieten der Akustik haben er und seine Schüler Wesentliches beigetragen, in frühen Jahren besonders zur Elektroakustik und zur akustischen Messtechnik. Geboren ist er am 21. Juli 1899 in Königshütte (Oberschlesien), seine Eltern waren der Postinspektor Paul Meyer und dessen Ehefrau Margarethe, geb. Schleiffer. Gestorben ist Erwin Meyer am 6. März 1972 in Pontresina (Schweiz). Das Foto in Abbildung 1 zeigt ihn im Alter von 65 Jahren. Für sein Berufsleben waren drei Stationen wichtig: Breslau, Berlin und Göttingen.

show abstract

“…Spring-mass models are typically used in acoustic architecture to separate environments with rational use of the space available. Other more recent but consolidated technologies exploit the use of porous materials as perforated 8 – 10 and/or microperforated panels 11 , or through thermo-viscous acoustic energy dissipation in the internal porous skeletons of foams with various internal geometry and materials compositions 12 – 16 . Thermo-viscous energy dissipation technologies also theoretically allow acoustic dampening of any frequency, with the only limitation represented by the available room for the porous liners.…”

Section: Introductionmentioning

confidence: 99%

Acoustic transmission loss in Hilbert fractal metamaterials

Comandini,

Ouisse,

Ting

et al. 2023

Sci Rep

View full text Add to dashboard Cite

Acoustic metamaterials are increasingly being considered as a viable technology for sound insulation. Fractal patterns constitute a potentially groundbreaking architecture for acoustic metamaterials. We describe in this work the behaviour of the transmission loss of Hilbert fractal metamaterials used for sound control purposes. The transmission loss of 3D printed metamaterials with Hilbert fractal patterns related to configurations from the zeroth to the fourth order is investigated here using impedance tube tests and Finite Element models. We evaluate, in particular, the impact of the equivalent porosity and the relative size of the cavity of the fractal pattern versus the overall dimensions of the metamaterial unit. We also provide an analytical formulation that relates the acoustic cavity resonances in the fractal patterns and the frequencies associated with the maxima of the transmission losses, providing opportunities to tune the sound insulation properties through control of the fractal architecture.

show abstract

Absorption of Sound by Porous Materials

Cited by 6 publications

References 1 publication

Swimming movements of ctenophores, and the mechanics of propulsion by ctene rows

Swimming movements of ctenophores, and the mechanics of propulsion by ctene rows

Erwin Meyer

Acoustic transmission loss in Hilbert fractal metamaterials

Contact Info

Product

Resources

About