It has been shown recently that the acoustic performance of the extended tube expansion chambers can be improved substantially by making the extended inlet and outlet equal to half and quarter chamber lengths, duly incorporating the end corrections due to the evanescent higher order modes that would be generated at the discontinuities. Such chambers, however, suffer from the disadvantages of hi...

This paper presents an operator-friendly and cost-efficient approach to characterize the dielectric permittivity of liquids flowing in narrow tubes, such as drainage tubes used part wound healing process hospitals. The is based on oscillator that characterization can be achieved with minimal operator (e.g., nurse) training. oscillator's frequency set by a 3D-printed cavity resonator offer flexi...

Acoustic energy, especially broadband low-frequency sound energy is part of the environmental mechanical acquisition cannot be ignored. Herein, a multi-tube parallel Helmholtz resonator-based triboelectric nanogenerator (MH-TENG) investigated to reap in noise environments. The designed MH-TENG consists modified resonator and thin-film TENG transducer. core materials transducer are aluminum, FEP...

A three dimensional model of a slotted tube resonator (STR) used as a probe in the magnetic resonance imaging (MRI), which is loaded by a dielectric body and surrounded by a conducting shield, is analyzed by using the variational method and the dyadic Green's function of a circular waveguide having a dielectric core. Three surface current modes are properly assumed to expand the currents on the...

According to the Waste Management Policy of European Union, recycling and reuse various wastes is considered most ecological advanced waste disposal technology with lowest impact on environment. By applying circular economy principles, plastic will extend its life cycle be used as secondary raw materials create structures good sound insulation absorption properties. Structures created from meta...

Abstract Acoustic Gas Thermometry (AGT) is one of the most accurate methods measuring thermodynamic temperature. The principal work this research design measurement platform AGT with a Pulse tube refrigerator temperatures between 4.2∼20K. static simulation spherical resonator are concluded. Stress checking and heat leakage analysis system emphasized. will be experimental used in future.

A time-domain computational approach is applied to investigate the behavior of perforated tube silencers at high sound levels. The one-dimensional computational technique employs a lumped parameter model for the perforate flows. The lumped parameter perforate model is based on time-invariant approximations for the equivalent length l(eq) and resistance R, consistent with the use of a nonlinear ...

Thermoacoustic instabilities can arise in systems where unsteady heat release is favorably coupled with acoustic pressure oscillations. A modified Rijke tube with segments having different sections is found to have lower threshold levels of heat addition rate needed for exciting the fundamental acoustic mode of the tube. Experiments indicate that about 115 W of heating power is required to prod...

A Helmholtz resonator with a curved cavity is studied for reducing jet-installation noise in configuration comprised by subsonic jet and nearby flat plate. The face-sheet are designed the Guess method impedance verified through an experiment simulation of tube. Both single double degree-of-freedom liners, latter perforated septum inside cavity, studied. good agreement obtained curves from desig...