2 edition of effects of flow on Helmholtz resonators found in the catalog.
effects of flow on Helmholtz resonators
Written in English
Thesis (M.Phil.) - Loughborough University, 1998.
|Statement||by Young-Chul Shin.|
Shin proposed a theoretical method for analyzing the effect of a flow on Helmholtz resonators. [ 10 ] These investigations have mainly studied the effect of a mean flow on duct systems with a finite number of HRs, while there are significantly fewer studies on acoustic wave propagation properties of the correspondence infinite system in the. The mean flow significantly influences the acoustic impedance of the Helmholtz resonator and there is no a unified model to predict the effect of flow on the acoustic impedance of the Helmholtz resonator and it will be determined by investigating the lumped parameters under different air flow Cited by: 3.
Installing resonators, such as Helmholtz resonators, or side branch tubes. 2. Using an orifice to increase damping. 3. Changing the length or the diameter of the chamber or duct, making holes in the chamber, and inserting a baffle plate. 4. Reducing the upstream volume flow of . A single side branch Helmholtz resonator has been tested in a circular duct in which both sound and an air flow could be passed in the same direction. The sound input was broad band and the transfer function across the resonator was determined by using two microphones and a cross-correlation analysis technique in which the broad band sound input was cross-correlated with each Cited by:
Experiments on the influence of flow on sound attenuation in absorbing ducts. 3. B. PHILLIPS NASA TM-X Effects of high wave amplitude and mean flow on a Helmholtz resonator. 4. J. S. ANDERSON The City University, Research Memorandum ML The effect of an air flow on a Helmholtz resonator. by: Effect of grazing flow on the acoustic impendance of Helmholtz resonators consisting of single and clustered orifices. Washington, D.C.: National Aeronautics and Space Administration, Scientific and Technical Information Branch; [Springfield, Va.: For sale by the National Technical Information Service], (OCoLC) Material Type.
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The transmission loss of Helmholtz resonators is measured using a flow-impedance tube setup to identify mean flow effects. First, Helmholtz resonators under two different flow conditions, grazing.
The effectiveness of the Helmholtz resonator as a narrow band acoustic attenuator, particularly at low frequencies, makes it a highly desirable component in a wide variety of applications, including engine breathing systems.
The present study investigates the influence of mean flow grazing over the neck of such a configuration on its acoustic performance both computationally and Cited by: 4. The effect of flow on the acoustic characteristics of a Helmholtz resonator is investigated experimentally.
An impedance tube set-up has been modified to. A theoretical investigation into the effects of flow on Helmholtz resonators has been carried out in order to improve the predicted performance of resonators.
The presence of a mean flow in the duct to which the neck of the Helmholtz resonator is effects of flow on Helmholtz resonators book has a great influence on the acoustic performance of the resonator, resulting in a discrepancy between the predicted and the measured Cited by: 1.
Effect of grazing flow on the acoustic impedance of Helmholtz resonators consisting of single and clustered orifices. A 'read' is counted each time someone views a publication summary (such as the.
As mentioned before, the self-sustained oscillations of a Helmholtz resonator in many cases is a continuous interaction of hydrodynamic and acoustic mechanisms.
In the frequency domain, the flow excitation and the acoustic behavior can be represented as transfer functions. The flow can be decomposed into two volume velocities. Cited by.
Effect of extended necks on transmission loss performances of Helmholtz resonators in presence of a grazing flow. Aerospace Science and Technology, Vol. AR 4 elliptic jet control with limiting tab. 24 January | Fluid Dynamics Research, Vol.
50, No. by: The effect of the Helmholtz resonator attached to the boundary of the flow path can be represented by substituting its impedance into the damping matrix of second order differential equation.
As such, the finite element method can be a_pplied to analyze the acoustic environments with Helmholtz resonator attachments.
model the interaction of a turbulent boundary layer with a Helmholtz resonator has been considered and the characteristics of the flow inside the resonator and over the orifice for various flow conditions are also analysed. Introduction A Helmholtz resonator exposed to a grazing flow with a specific speed can produce strong flow fluctuations.
The acoustic characteristics of a dual Helmholtz resonator in the presence of flow is investigated theoretically and experimentally. A lumped parameter model is introduced, including the damping effect and neck inertia, and the predicted transmission loss (TL) is compared with experiments performed with a flow-impedance tube setup.
^Predicted and measured results with flow exhibit a good. The effects of grazing flow on the impedance of Helmholtz resonators consisting of clusters of orifices was also studied.
In general, both resistance and reaction were found to be virtually independent of orifice relative spacing and number. These. The present work experimentally investigates pulsating flow characteristics of the engine intake manifold and the effects of a Helmholtz resonator with variable internal volume.
In this paper, acoustic studies were used to model the intake manifold and to develop a complex expression to determine the natural frequency of the by: 1. Flow visualization in long neck Helmholtz resonators with grazing flow. Acoustic Characterization of a Helmholtz Resonator Under Grazing Flow Conditions Using a Hybrid Methodology.
Effect of grazing flow on the acoustic impedance of Helmholtz resonators consisting of. Grazing flow and oscillatory flow in an orifice were studied in a plexiglass flow channel with a single side branch Helmholtz resonator using water as the fluid medium.
An equation for the resonance frequency of a Helmholtz resonator was developed from the wave equation for the case of a cavity volume that was a rectangular parallelepiped and an orifice the flow from which had a constant velocity by: Panton, R.
Effect of orifice geometry on Helmholtz resonator excitation by grazing flow. AIAA J. 28, 60 – Panton, R. & Miller, J. Excitation of a Helmholtz resonator by turbulent boundary by: See → Sects.
H.4 – H for a more detailed description of Helmholtz resonators without flow and → Sects. J – J for non-linear effects of flow. Open image in new window This is a preview of subscription content, log in to check access. Numerical Investigation of the Effect of Grazing Flow to Sound Absorption on Helmholtz Resonator.
Effect of grazing flow on the acoustic impedance of Helmholtz resonators consisting of single and clustered orifices. The Helmholtz resonator concept has been analysed in various configurations to evaluate the effect of the size and arrays on the overall noise attenuation performance.
The response of single two- and three-dimensional Helmholtz resonators subject to external excitation by a plane acoustic wave is studied. The inviscid linearized problem is solved by the matched-asymptotic-expansion technique in the low-frequency limit, i.e.
when the characteristic neck dimension is small compared with the acoustic by:. An Introduction to Acoustics S.W. Rienstra & A. Hirschberg Eindhoven University of Technology 28 Nov This is an extended and revised edition of IWDE Comments and corrections are gratefully accepted.
This ﬁle may be used and printed, but for personal or educational purposes only. c S.W. Rienstra & A. Hirschberg 1 The streamwise and spanwise effects of flow-excited Helmholtz resonators on a three-dimensional turbulent boundary layer Farzin Ghanadi*, Maziar Arjomandi, Ben Cazzolato and Anthony Zander School of Mechanical Engineering, University of Adelaide, SAAustralia.Helmholtz resonators are used in exhaust systems, as they can attenuate a specific narrow frequency band.
The presence of a flow in the system alters the acoustic properties of the resonator and the transmission loss of the subsystem.
In this tutorial model, a Helmholtz resonator is located as a side branch to a main duct.