Abstract
The so-called air-jet-generator for acoustic waves has been several times described1–5. We may therefore in this introduction confine ourselves to a brief statement of the fundamental principle. The generator depends on an air-jet with super sound-velocity. Such a jet is produced if air streams from a container, in which the excess-pressure exceeds 0.9 atm, into the free atmosphere. It is known from investigations carried out by E. Mach and P. Salcher6, R. Emden7 and others, that the jet exhibits a peculiar structure of which a picture may he obtained by means of the method of striae (Fig. 1). As is generally known the explanation of the picture has been given by L. Prandtl8. To the periodic aspect of the structure corresponds a periodic variation of the static pressure and of the velocity in the jet, as proved for instance by Stodola9. The static pressure has minima in the centres of the jet-sections and maxima in the borderlines between the said sections while for the velocity the opposite distribution prevails. If the sound of a simple Pitot-apparatus, (Fig. 2), is moved along the axis of the jet, the aperture being directed against the flow, the reading of the apparatus will also vary in a periodic way. Fig. 3 shows a Pitot-curve found with a jet-orifice of 0.535 mm and an excess-pressure of 141 cm Hg. The maxima are nearly in the centres of the jet-sections.
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Referenzen
Om en ny Metode til Frembringelse af Lydsvingninger. Det kgl. danske Vidensk. Selsk. math.-fys. Medd.’ I, 13, 1919.
On a new Method for the Generation of Sound-Waves. Phys.Rev. vol. XX, 719, 1922.
New Investigation on the Air-Jet Generator for acoustic Waves. Det kgl. danske Vidensk. Selsk. math.-fys. Medd. VII, 6, 1926.
A new acoustic Generator. J. of Scientific Instruments. Vol. IV, Nr. 4, p. 101, 1927.
Modus Operandi of the Air-Jet Pulsator. Det kgl. danske Vidensk. Selsk. math.-fys. Medd. X, 4, 1930 (complete account).
Mach, E. u. P. Salcher: Wied. Ann. 41, p. 144, 1890.
Emden, P.: Wied. Ann. 69, p. 426, 1899.
Prandtl, L.: Phys. Z. 5, p. 599, 1904 and 8, p. 23, 1907.
Stodola, A.: Die Dampfturbinen. Berlin 1910.
Riemann-Weber: Die partiellen Differentialgleichungen. 5. Aufl. Bd. 2, S. 481, Braunschweig 1912.
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Hartmann, J. (1930). Modus Operandi of the Air-Jet Pulsator. In: Gilles, A., Hopf, L., v. Kármán, T. (eds) Vorträge aus dem Gebiete der Aerodynamik und verwandter Gebiete. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-662-33791-2_26
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DOI: https://doi.org/10.1007/978-3-662-33791-2_26
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