Sound emission in a nonequilibrium medium from a plane surface with periodically varying temperature

1976 ◽  
Vol 16 (3) ◽  
pp. 478-482
Author(s):  
A. S. Pleshanov
Keyword(s):  
Plane Surface ◽  
Sound Emission ◽  
Nonequilibrium Medium

Hydrodynamic instability and shear layer effect on the sound emission of a turbulent jet flame

2015 ◽  
Author(s):  
Stephan Schlimpert ◽  
Seong Ryong Koh ◽  
Antje Feldhusen ◽  
Benedikt Roidl ◽  
Matthias H. Meinke ◽  
...  
Keyword(s):  
Shear Layer ◽  
Hydrodynamic Instability ◽  
Turbulent Jet ◽  
Sound Emission ◽  
Jet Flame ◽  
Layer Effect

scholarly journals A Study of Moist Air Condensation Characteristics in a Transonic Flow System

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 4052
Author(s):  
Jie Wang ◽  
Hongfang Gu
Keyword(s):  
Mach Number ◽  
Relative Humidity ◽  
Transonic Flow ◽  
Flow System ◽  
Plane Surface ◽  
Droplet Growth ◽  
Moist Air ◽  
Dry Air ◽  
Hydraulic Equipment ◽  
Non Equilibrium

When water vapor in moist air reaches supersaturation in a transonic flow system, non-equilibrium condensation forms a large number of droplets which may adversely affect the operation of some thermal-hydraulic equipment. For a better understanding of this non-equilibrium condensing phenomenon, a numerical model is applied to analyze moist air condensation in a transonic flow system by using the theory of nucleation and droplet growth. The Benson model is adopted to correct the liquid-plane surface tension equation for realistic results. The results show that the distributions of pressure, temperature and Mach number in moist air are significantly different from those in dry air. The dry air model exaggerates the Mach number by 19% and reduces both the pressure and the temperature by 34% at the nozzle exit as compared with the moist air model. At a Laval nozzle, for example, the nucleation rate, droplet number and condensation rate increase significantly with increasing relative humidity. The results also reveal the fact that the number of condensate droplets increases rapidly when moist air reaches 60% relative humidity. These findings provide a fundamental approach to account for the effect of condensate droplet formation on moist gas in a transonic flow system.

Artifact Design and Measurement Error Analysis in the Evaluation of Lead Measurement Accuracy of Helical Gear Using Wedge Artifact

2010 ◽  
Vol 132 (7) ◽  
Author(s):  
Masaharu Komori ◽  
Fumi Takeoka ◽  
Aizoh Kubo ◽  
Kazuhiko Okamoto ◽  
Sonko Osawa ◽  
...  
Keyword(s):  
Evaluation Method ◽  
Plane Surface ◽  
Design Method ◽  
Measuring Instrument ◽  
Setting Error ◽  
Geometrical Form ◽  
Measurement Experiment ◽  
Mechanical Devices ◽  
Tooth Flank ◽  
Artifact Design

The reduction in the vibration and noise of gears is an important issue in mechanical devices such as vehicles and wind turbines. The characteristics of the vibration and noise of gears are markedly affected by deviations of the tooth flank form of micrometer order; therefore, strict quality control of the tooth flank form is required. The accuracy of the lead measurement for a gear-measuring instrument is usually evaluated using a helicoid artifact. However, it is difficult to manufacture it with high accuracy because the helix is a complicated geometrical form. To solve this problem, a method of evaluating a gear-measuring instrument using a wedge artifact, which includes a highly precise plane surface, has been proposed. In this research, to put the wedge artifact into practice, a design method of the wedge artifact is developed. In addition, the effects of the measuring condition and the setting error of the wedge artifact on the measurement result are investigated. The uncertainty for the evaluation method using a wedge artifact is assessed by a measurement experiment and simulation.

scholarly journals An introduction to Acoustic Emission Analysis (AEA) based medical diagnostic techniques: Screening and Monitoring of cartilage defects in knee joint osteoarthrosis

2020 ◽  
Vol 6 (3) ◽  
pp. 518-521
Author(s):  
Subke Joerg ◽  
Krueger Sabine ◽  
Junker Heinz-Otto ◽  
Schwalbe Hans-Joachim ◽  
Franke Ralf-Peter ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Load Transfer ◽  
Plane Surface ◽  
Cartilage Damage ◽  
Diagnostic Techniques ◽  
Outer Edge ◽  
Cartilage Defects ◽  
Emission Analysis ◽  
Medical Diagnostic ◽  
Therapeutic Measures

AbstractClinical studies have shown that during standardized movements the Acoustic Emission (AE) from lesions in articular cartilage can be assessed. Specific lesions produce specific acoustic signals, therefore it is possible to evaluate the character of cartilage damage. Consequently it is possible to evaluate the condition of the joint cartilage in order to enhance therapy. Patients performed series of knee bends, first on a plane surface in order to assess the cartilage lesions. Then patients performed knee bends on boards simulating orthopaedic insoles by means of inner and outer edge elevations. Insoles aim at relieving the lesioned areas of cartilage from loads and strain. AEA monitoring reveals the effects of a shift of the zone of load transfer immediately and is an adequate tool for the diagnosis as well as the monitoring of therapeutic measures.

scholarly journals The approach of a vortex pair to a plane surface in inviscid fluid

1979 ◽  
Vol 92 (3) ◽  
pp. 497-503 ◽  
Author(s):  
P. G. Saffman
Keyword(s):  
Approximate Calculation ◽  
Plane Surface ◽  
Vortex Pair ◽  
Plane Wall ◽  
Inviscid Fluid ◽  
Viscous Effects ◽  
Axis Ratio ◽  
Local Rate

It is shown that a symmetrical vortex pair consisting of equal and opposite vortices approaching a plane wall at right angles must approach the wall monotonically in the absence of viscous effects. An approximate calculation is carried out for uniform vortices in which the vortices are assumed to be deformed into ellipses whose axis ratio is determined by the local rate of strain according to the results of Moore & Saffman (1971).

Sign in / Sign up

Export Citation Format

Share Document