Dynamic properties of a steel–UHPC composite deck with large U-ribs: Experimental measurement and numerical analysis

2020 ◽  
Vol 213 ◽  
pp. 110569
Author(s):  
Xun Zhang ◽  
Xi Li ◽  
Rui Liu ◽  
Chenxi Hao ◽  
Zhiyang Cao
Keyword(s):  
Numerical Analysis ◽  
Experimental Measurement ◽  
Dynamic Properties

Damping Behavior of Blades From Small Radial Turbines

2015 ◽  
Author(s):  
David Hemberger ◽  
Dietmar Filsinger ◽  
Hans-Jörg Bauer
Keyword(s):  
Numerical Analysis ◽  
Dynamic Properties ◽  
Forced Response ◽  
Operating Conditions ◽  
Fe Model ◽  
Structural Damping ◽  
Aerodynamic Damping ◽  
Damping Behavior ◽  
Aerodynamic Properties ◽  
Radial Turbines

Next to excitation forces and the dynamic properties of mistuned structures the damping behavior is a key feature to evaluate the dynamic turbine blade response and thus the HCF life of a bladed disk (blisk). Just as the determination of the mistuning properties and the assessment of the vibration excitation, the evaluation of damping is also subject to uncertainty especially considering the wide operating range of a small radial turbine of a turbocharger. Since the total damping is composed of material damping, structural damping and aerodynamic damping, which are affected by parameters, like the eigenform of the vibration, the magnitude of the vibration amplitude and aerodynamic properties, the total damping can be strongly dependent on the operating conditions. The study at hand provides results from investigations that allow estimating the contribution of aerodynamic damping on the total damping. Experimental and numerical analysis of radial turbines from turbochargers for vehicular engines with variable turbine inlet vanes were performed. Measurements under different environmental conditions such as at rest and during operation, as well as unsteady CFD calculations and, coupled flow and structural calculations were carried out. A change in total damping could be found depending on the density of the surrounding gas by vibration measurements in operation on the hot gas test bench. But it was also shown that the total damping is decisively influenced by the mistuning of the structure. On one side the structural damping is varied by the variation in mistuned blade vibration amplitudes and otherwise the aerodynamic damping is influenced by the different inter blade phase angles (IBPA ) due to the mistuning, which is a symptom of geometric differences and material inhomogeneity in the wheels. Finally, the estimated total damping values were utilized in forced response calculations using a mistuned FE-model of a real turbine and excitation forces from unsteady CFD calculation. The magnitudes of the measured vibration amplitudes were compared with results from numerical analysis to validate the numerical model with focus on the investigation about the total damping. The deviation between the results was ±10% for different eigenforms and excitation orders.

Numerical Analysis and Measurement Results of a Window Sill

2014 ◽  
Vol 899 ◽  
pp. 147-150 ◽  
Author(s):  
Dušan Katunský ◽  
Marek Zozulák ◽  
Kristián Kondáš ◽  
Jozef Šimiček
Keyword(s):  
Numerical Analysis ◽  
Boundary Conditions ◽  
Experimental Measurement ◽  
Thermal Field ◽  
Construction Materials ◽  
Field Analysis ◽  
Dynamic Boundary Conditions ◽  
The Real ◽  
Dynamic Boundary ◽  
Measurement Results

Window sill of brick walls is one of the most critical places in a connection of two envelope types objectively. If there are the transparent and opaque parts present together, the connection is much more complicated. Different behavior of the construction materials in dynamic boundary conditions causes deformations of thermal field of the window sill detail. Numerical thermal field analysis verified by the experimental measurement in experimental outdoor chambers is used for recognize the real heat-air-moisture behavior in the various constructions.

scholarly journals Experimental measurement of dynamic loading and numerical analysis of gas pipeline damaged by corrosion

2021 ◽  
Vol 352 ◽  
pp. 00008
Author(s):  
Martin Magura ◽  
Ján Brodniansky ◽  
Ján Brodniansky
Keyword(s):  
Numerical Analysis ◽  
Dynamic Loading ◽  
Experimental Measurement ◽  
Gas Pipeline ◽  
Dynamic Measurements ◽  
Casing Pipe

The paper presents the results of the expert works in the area of diagnostics, repair, and reconstruction of the steel pipelines of the transit gas pipeline (TP) on Slovak territory. One part of our work included dynamic measurements of a steel casing pipe located under the railway. This pipeline was damaged by corrosion and it was necessary to evaluate its safety.

scholarly journals Dynamic and static properties of stadium-shaped antidot arrays

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
E. Saavedra ◽  
R. M. Corona ◽  
N. Vidal-Silva ◽  
J. L. Palma ◽  
D. Altbir ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Numerical Analysis ◽  
Dynamic Properties ◽  
Dynamic Susceptibility ◽  
Two Dimensional ◽  
Static Properties ◽  
Micromagnetic Simulations ◽  
Circular Holes ◽  
Antidot Arrays

AbstractIn this work we performed a detailed numerical analysis on the static and dynamic properties of magnetic antidot arrays as a function of their geometry. In particular, we explored how by varying the shape of these antidot arrays from circular holes to stadium-shaped holes, we can effectively control the magnetic properties of the array. Using micromagnetic simulations we evidenced that coercivity is very sensitive to the shape of antidots, while the remanence is more robust to these changes. Furthermore, we studied the dynamic susceptibility of these systems, finding that it is possible to control both the position and the number of resonance peaks simply by changing the geometry of the holes. Thus, this work provides useful insights on the behavior of antidot arrays for different geometries, opening routes for the design and improvement of two-dimensional technologies.

scholarly journals Numerical Analysis of General Trends in Single-Phase Natural Circulation in a 2D-Annular Loop

2008 ◽  
Vol 2008 ◽  
pp. 1-10 ◽  
Author(s):  
Gilles Desrayaud ◽  
Alberto Fichera
Keyword(s):  
Natural Convection ◽  
Numerical Analysis ◽  
Single Phase ◽  
Closed Loop ◽  
Dynamic Properties ◽  
Natural Circulation ◽  
Flow Behavior ◽  
Pitchfork Bifurcation ◽  
Chaotic Flow ◽  
Over The Top

The aim of this paper is to address fluid flow behavior of natural circulation in a 2D-annular loop filled with water. A two-dimensional, numerical analysis of natural convection in a 2D-annular closed-loop thermosyphon has been performed for various radius ratios from 1.2 to 2.0, the loop being heated at a constant flux over the bottom half and cooled at a constant temperature over the top half. It has been numerically shown that natural convection in a 2D-annular closed-loop thermosyphon is capable of showing pseudoconductive regime at pitchfork bifurcation, stationary convective regimes without and with recirculating regions occurring at the entrance of the exchangers, oscillatory convection at Hopf bifurcation and Lorenz-like chaotic flow. The complexity of the dynamic properties experimentally encountered in toroidal or rectangular loops is thus also found here.

Sign in / Sign up

Export Citation Format

Share Document