Experimental Study of Acoustic Wave Propagation through Resonating Devices

1998 ◽  
Vol 5 (1) ◽  
pp. 39-55
Author(s):  
Y.K. Lai ◽  
C.F. Ng
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
Function Method ◽  
Transmission Loss ◽  
Stop Band ◽  
Resonance Scattering ◽  
Acoustic Wave Propagation ◽  
Transfer Function Method ◽  
Bandwidth Control ◽  
Filter Effects

The acoustic filter effects of periodic obstructions in a square section of duct are studied experimentally. The two-microphone transfer function method is employed to measure the transmission loss across the periodic elements of different profiles. The experiments aim to measure the Bragg Stop Band and the Resonance Scattering Stop Band and their interaction. The experimental data show that the Bragg effect is spatial dependent. The Resonance Scattering Stop Band is strongly affected by obstacles and demonstrates a possibly useful interaction between the Bragg Stop Band and the Resonance Scattering Stop Band. Results also indicate that for specific situations, the overall Resonance Scattering Stop Band contribution can be dominant and effective, both in terms of magnitude and bandwidth control. The asymmetric placement of the obstructing elements is shown to be nonreversible.

Measurement of the Incident Sound Power in Ducts and Effect Factors Analysis

2011 ◽  
Vol 467-469 ◽  
pp. 841-846
Author(s):  
Hai Jun Zhao ◽  
Zhao Xiang Deng
Keyword(s):  
Function Method ◽  
Transmission Loss ◽  
Measuring Method ◽  
Sound Power ◽  
Effect Factors ◽  
Complex Reflection Coefficient ◽  
Transfer Function Method ◽  
Factors Analysis ◽  
Program Comparison ◽  
Perforated Tube

Based on two-microphone transfer function method, the measuring method of incident sound power in duct is introduced, The special test equipment is built, and the test and measurement program of incident sound power in duct is written, and effect factors of measurement are analyzed. Results are shown that temperature, flow velocity, microphone spacing deviation and complex reflection coefficient influences less on the program. Transmission loss of perforated tube muffler with no flow is measured using the program, comparison is carried out with results of finite element method, they agrees with well, and with flow sound power of flow regeneration from the muffler is also done, an important foundation is provided for quantitative study on occurring mechanism flow regenerated noise and enhancing attenuation performance of muffler.

Experimental Study on Dynamic Characteristics and Seismic Response Analysis of Yingxian Wooden Pagoda

2012 ◽  
Vol 433-440 ◽  
pp. 6077-6083
Author(s):  
Xu Yan ◽  
Tie Ying Li
Keyword(s):  
Experimental Study ◽  
Transfer Function ◽  
Function Method ◽  
Seismic Waves ◽  
Response Analysis ◽  
Vibration Modes ◽  
Test Results ◽  
Seismic Response Analysis ◽  
Horizontal Vibration ◽  
Transfer Function Method

In order to have a better understanding of the vibration characteristics, micro tremor measurements are carried out on Yingxian Wooden pagoda. Horizontal vibration modes of the tower and the torsional vibration modes on each floor are attained by analysis of the test results. Based on transfer function method, elastic displacements of the tower under the different seismic waves are derived. Trough theoretical analysis, the significative conclusions are received as a basis for researching and protecting the ancient building.

EXPERIMENTAL STUDY OF THE KINEMATIC PARAMETERS OF MOVEMENT OF CARS FORCED IDLE MOTION

2018 ◽  
pp. 52-57
Author(s):  
Ivelin Kostov
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
Experimental Research ◽  
Kinematic Parameters ◽  
Research Results ◽  
Software Product

In the work brought some experimental data of kinematic parameters of movement of cars forced idle, as the software product was used to diagnose 900 ATS, which recorded kinematic parameters of vehicle. On the basis of the conducted experimental research results are shown tabulated and analysed.

Experimental study of hypochloremia

1935 ◽  
Vol 31 (8-9) ◽  
pp. 1112-1112
Keyword(s):  
Experimental Data ◽  
Experimental Study

Analyzing clinical and experimental data on hypochloremia, the authors show that both during vomiting and when giving diuretica, it is not only about the loss of chlorine, but at the same time a large amount of water is lost.

Kinetics of hypso anhydrites dissolution in water. Experimental studies

2019 ◽  
pp. 93-96
Author(s):  
A. L. Lebedev ◽  
I. V. Avilina
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
Riccati Equation ◽  
Balance Equation ◽  
Experimental Studies ◽  
Common Ion ◽  
The Common ◽  
Common Ion Effect ◽  
Kinetics Of Dissolution ◽  
Kinetics Of

Experimental study of kinetics of dissolution of hypso anhydrites at 25 ᵒC made it possible to formulate model of the process in the form of a balance equation for the kinetics of dissolution of gypsum, anhydrite (first and second orders, respectively) and kinetics of precipitation of gypsum (second order). The processing of the experimental data were carried out on the basis of the solution of the Riccati equation. When taking into account the common-ion effect on the solubility of gypsum and anhydrite, the calculated values turned out to be more comparable with the experimental ones.

Effect of Tightening Speed on the Torque-Tension and Wear Pattern in Bolted Connections

2006 ◽  
Author(s):  
Sayed A. Nassar ◽  
Ramanathan M. Ranganathan ◽  
Saravanan Ganeshmurthy ◽  
Gary C. Barber
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
Surface Roughness ◽  
Initial Level ◽  
Zinc Coating ◽  
Optical Microscope ◽  
Wear Pattern ◽  
Highly Sensitive ◽  
Contact Surfaces ◽  
Scanning Electron

This experimental study investigates the effect of tightening speed and coating on both the torque – tension relationship and wear pattern in threaded fastener applications. The fastener torque – tension relationship is highly sensitive to normal variations in the coefficients of friction between threads and between the turning head and the surface of the joint. Hence, the initial level of the joint clamp load and the overall integrity and reliability of a bolted assembly is significantly influenced by the friction coefficients. The effect of repeated tightening and loosening is also investigated using M12, Class 8.8, fasteners with and without zinc coating. The torque – tension relationship is examined in terms of the non-dimensional nut factor K. The wear pattern is examined by monitoring the changes in surface roughness using a WYKO optical profiler and by using a LECO optical microscope. A Hitachi S-3200N Scanning Electron Microscope (SEM) is used to examine the contact surfaces, under the fastener head, after each tightening/loosening cycle. Experimental data on the effect of variables and the tightening speed, fastener coating and repeated tightening on the nut factor are presented and analyzed for M8 and M12, class 8.8, fasteners.

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