National Repository of Grey Literature 23 records found  previous11 - 20next  jump to record: Search took 0.00 seconds. 
Nonlinear elasic wave spectroscopy methods used to detect defects in solids
Kvita, Pavel
Using of nonlinear elastic wave methods (frequency mixing method and TRA method) in aircraf wing panel NDT is discussed in the paper.
Numerical simulation of interaction of a vibrating airfoil with turbulent flax
Dubcová, L. ; Feistauer, M. ; Horáček, Jaromír ; Sváček, Petr
The report deals with numerical simulations of 2D viscous incompressible flow around a rotationaly vibrating profile. The flow is described by continuity and Navier-Stokes equations. Solution of the partial differential equations is based on finite element method. Because the Reynolds numbers higher than 10 000 are considered the solution is stabilized by SUPG method. Alge-braic turbulence model is taken into account and for simulations of the flow on moving grids the ALE method is used. the method was applied on harmonie vibrations of the profil NACA 0012 and the results are in good agreement with the experimental data obtained in ARTI.
Time reversal acoustic used to defect detection in structures
Převorovský, Zdeněk
Time reversal acoustics (TRA) method application in defects detection is described in the paper. Non-linear version of the TRA is discussed primarily.
Using of NEWS frequency mixing method for defects detection in aircraft structures
Kvita, Pavel ; Převorovský, Zdeněk
Frequency mixing NEWS method application in defects detection in model aircraft structure is main goal of the paper.
Expert AE signal arrival detection
Chlada, Milan
New method of AE signal arrival detection is described in the paper. The method is based on AE signal energy and local gravity center monitoring.
Visualization of unsteady flows around vibrating profile
Vlček, Václav ; Horáček, Jaromír ; Luxa, Martin ; Veselý, Jan ; Vaněk, František ; Bula, Vítězslav ; Vávra, J.
The contribution presents preliminary results of interferometry measurements of flow field around a vibrating double circle 18% profile above the critical airflow velocity for loss of the system stability by flutter. The measurements were performed in subsonic wind tunnel for prescribed phase delays during one oscillation period of the profile with two degrees of freedom for rotation and translation.
Measurement of unsteady flow fields around a vibrating profile by optical methods
Horáček, Jaromír ; Vlček, Václav ; Luxa, Martin ; Veselý, Jan ; Vaněk, František ; Bula, Vítězslav ; Vávra, J.
The report presents preliminary results of interferometry measurements of flow field around a vibrating double circle 18% profile above the critical airflow velocity for loss of the system stability by flutter. The measurements were performed in subsonic wind tunnel for prescribed phase delays during one oscillation period of the profile with two degrees of freedom for rotation and translation.
Pollutant diffusion in the idealized build-up area
Šeděnková, Hana ; Jaňour, Zbyněk ; Leitl, B.
The essence of the problem consist in the way of pollutant diffusion in the urban build-up area. The measurement of the concentration field of the emission from the point (chimney) and line (street) source in the model of the idealized urban build-up area was done in the boundary layer wind tunnel. Dependence on the location of this source against model and also dependence on the geometric setting of the model (both density of buildings and location of street canyons) was found.
ALE method application on interaction of flowing fluid with a vibrating airfoil
Růžička, M. ; Feistauer, M. ; Horáček, Jaromír ; Sváček, P.
Paper deals with the numerical solution of aeroelastic problem for an airfoil with two-degrees of freedom vibrating in 2D viscous incompressible fluid flowing in a channel. The airfoil is considered as a solid body vibrating with large amplitudes in traslation and rotation. Mathematical model for fluid is given by the unsteady Navier-Stokes equations, continuity equation and initial and mixed boundary conditions.
Lokalizace zdrojů AE pomocí neuronových sítí na základě signálových parametrů
Chlada, Milan ; Blaháček, Michal ; Převorovský, Zdeněk
The new method of the AE source location by artificial neural networks, which process extracted signal parameters and do not consider the arrival time differences, is introduced.

National Repository of Grey Literature : 23 records found   previous11 - 20next  jump to record:
Interested in being notified about new results for this query?
Subscribe to the RSS feed.