Dynamic behaviour of a short span soil–steel composite bridge for high-speed railways – Field measurements and FE-analysis

2014 ◽  
Vol 69 ◽  
pp. 49-61 ◽  
Author(s):  
Peyman Mellat ◽  
Andreas Andersson ◽  
Lars Pettersson ◽  
Raid Karoumi
Keyword(s):  
High Speed ◽  
Dynamic Behaviour ◽  
Field Measurements ◽  
Fe Analysis ◽  
Composite Bridge ◽  
Steel Composite ◽  
Short Span

Characteristics of Stable Rotating Stall Cells in an Axial Compressor

2017 ◽  
Author(s):  
Adam R. Hickman ◽  
Scott C. Morris
Keyword(s):  
Flow Field ◽  
High Speed ◽  
Pressure Ratio ◽  
Pressure Sensors ◽  
Axial Compressor ◽  
Field Measurements ◽  
Rotating Stall ◽  
Flow Coefficient ◽  
Stable Operation ◽  
Double Phase

Flow field measurements of a high-speed axial compressor are presented during pre-stall and post-stall conditions. The paper provides an analysis of measurements from a circumferential array of unsteady shroud static pressure sensors during stall cell development. At low-speed, the stall cell approached a stable size in approximately two rotor revolutions. At higher speeds, the stall cell developed within a short amount of time after stall inception, but then fluctuated in circumferential extent as the compressor transiently approached a stable post-stall operating point. The size of the stall cell was found to be related to the annulus average flow coefficient. A discussion of Phase-Locked Average (PLA) statistics on flow field measurements during stable operation is also included. In conditions where rotating stall is present, flow field measurements can be Double Phase-Locked Averaged (DPLA) using a once-per-revolution (1/Rev) pulse and the period of the stall cell. The DPLA method provides greater detail and understanding into the structure of the stall cell. DPLA data indicated that a stalled compressor annulus can be considered to contained three main regions: over-pressurized passages, stalled passages, and recovering passages. Within the over-pressured region, rotor passages exhibited increased blade loading and pressure ratio compared to pre-stall values.

Development of a machining simulator considering machine behaviour

2003 ◽  
Vol 217 (9) ◽  
pp. 1333-1339 ◽  
Author(s):  
A Dugas ◽  
J J Lee ◽  
M Terrier ◽  
J Y Hascoët
Keyword(s):  
High Speed ◽  
Dynamic Behaviour ◽  
Three Dimensional ◽  
Milling Process ◽  
High Speed Machining ◽  
Tracking Errors ◽  
Tool Paths ◽  
Milling Operation ◽  
Dynamic Errors ◽  
Tool Deflections

High-speed machining gives much potential for increasing the efficiency of the milling operation, but it requires very careful preparation for the milling process to use this potential. A machining simulator has been developed that can analyse dynamic errors due to tool deflections and machine dynamic behaviour using a three-dimensional solid simulation model. This kind of simulator would be a useful tool to apply in high-speed machining where it is necessary to obtain very well prepared part programs considering dynamic errors as well as geometrical errors. In this short communication, an algorithm will be introduced to estimate the dynamic errors caused by machine dynamic behaviour. Specifically, this algorithm predicts real feed rates and tracking errors considering the limits of numerical controllers and machine tools. The efficiency of the algorithm has been verified through several experiments with various tool paths. In addition, the algorithm has been integrated into the machining simulator. Some results obtained from the machining simulator concerning the estimation of tracking errors will be reported.

scholarly journals Field measurements of aerodynamic pressures in tunnels induced by high speed trains

2012 ◽  
Vol 100 (1) ◽  
pp. 19-29 ◽  
Author(s):  
Yung-Yen Ko ◽  
Cheng-Hsing Chen ◽  
Ing-Tsang Hoe ◽  
Shin-Tsyr Wang
Keyword(s):  
High Speed ◽  
Field Measurements ◽  
High Speed Trains

scholarly journals Model Adjustment of Small Rotors for High Speed Gas Turbines

1990 ◽  
Author(s):  
Alain Delbez ◽  
Christian Beth ◽  
Daniel Gay
Keyword(s):  
Gas Turbines ◽  
High Speed ◽  
Dynamic Behaviour ◽  
Design Stage ◽  
Rotor Bearing ◽  
Angular Velocities ◽  
Model Adjustment ◽  
Experimental Approaches

In this paper, we present the studies which are carried out at MICROTURBO relating to rotor-bearing systems mounted in small high speed gas turbines. These studies are based on both theoretical and experimental approaches, and are aimed at providing an improved prediction of the dynamic behaviour of rotors at the design stage, in particular the critical angular velocities and sensitivity to unbalance.

Sign in / Sign up

Export Citation Format

Share Document