The One-Dimensional Unsteady Flow Prediction Method and Applications on the Pressure Waves Generated by High-Speed Trains Passing through a Tunnel

2012 ◽  
pp. 397-405
Author(s):  
Y. G. Mei ◽  
C. H. Zhou
Keyword(s):  
Unsteady Flow ◽  
High Speed ◽  
Prediction Method ◽  
Pressure Waves ◽  
One Dimensional ◽  
Flow Prediction ◽  
High Speed Trains ◽  
The One

The one-Dimensional Unsteady Flow Prediction Method for Pressure Waves in High-Speed Subway and its Applications

2011 ◽  
Vol 94-96 ◽  
pp. 1967-1970
Author(s):  
Chao Hui Zhou ◽  
Yuan Gui Mei
Keyword(s):  
Unsteady Flow ◽  
High Speed ◽  
Prediction Method ◽  
Pressure Waves ◽  
Subway Tunnel ◽  
One Dimensional ◽  
Flow Prediction ◽  
Cross Section Area ◽  
Section Area ◽  
The One

With the speed-up of subway, the discomfort problem of passengers caused by pressure waves becomes more and more serious. The prediction method of the pressure waves based on the one-dimensional unsteady compressible non-homentropic flow model and the method of characteristics is introduced, and the program is developed which can be used to calculate the pressure waves not only produced by single train passing through subway tunnel with airshafts, but also produced when the train starts or stops. On this base, the influence of the train speed and the cross-section area of airshafts to the comfort of passengers in the subway is researched. All these work provides the foundation for the development of the one-dimensional unsteady flow prediction method for pressure waves produced by the train passing through subway tunnel.

scholarly journals A Novel Deeper One-Dimensional CNN With Residual Learning for Fault Diagnosis of Wheelset Bearings in High-Speed Trains

IEEE Access ◽  
2019 ◽  
Vol 7 ◽  
pp. 10278-10293 ◽  
Author(s):  
Dandan Peng ◽  
Zhiliang Liu ◽  
Huan Wang ◽  
Yong Qin ◽  
Limin Jia
Keyword(s):  
Fault Diagnosis ◽  
High Speed ◽  
One Dimensional ◽  
Residual Learning ◽  
High Speed Trains

scholarly journals Study of Unsteady Flow in a Heat Exchanger by the Method of Characteristics

1992 ◽  
Vol 114 (4) ◽  
pp. 459-463 ◽  
Author(s):  
Yuan Mao Huang
Keyword(s):  
Heat Exchanger ◽  
Unsteady Flow ◽  
Transfer Rate ◽  
Method Of Characteristics ◽  
Governing Equations ◽  
One Dimensional ◽  
The Method Of Characteristics ◽  
Improvement Factor ◽  
The One ◽  
Good Agreement

The one-dimensional, unsteady flow in an air-to-air heat exchanger is studied. The governing equations are derived and the method of characteristics with the uniform interval scheme is used in the analysis. The effect of the fin improvement factor on the air temperature in the heat exchanger and the heat transfer rate of the heat exchanger, and air properties in the heat exchanger are analyzed. The numerical results are compared and show good agreement with the available data.

VERIFICATION OF THE SHB TEST RESULTS BASED ON THE ONE-DIMENSIONAL STRESS WAVE THEORY

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1068-1073
Author(s):  
TOMOKAZU MASUDA ◽  
KENJI SAITO ◽  
IZUMI MORITA ◽  
SHUSHI IKEDA ◽  
KOICHI MAKII ◽  
...  
Keyword(s):  
Strain Rate ◽  
Stress Wave ◽  
High Speed ◽  
Wave Theory ◽  
High Speed Photography ◽  
Strain Rates ◽  
One Dimensional ◽  
Strain And Strain Rate ◽  
Deformation Behaviors ◽  
The One

In order to evaluate dynamic deformation behaviors under high strain rates, Kobe Steel has developed and applied a Split-Hopkinson Bar (SHB) apparatus. This paper discusses the validity of the strain measurements and strain rates measured by this SHB apparatus. The strain waves that propagated in the incident and transmitted bars and the specimen are captured using a high-resolution type high-speed photography in detail. The strain wave propagated many times in the incident and transmitted bars and the specimen when the specimen was not broken. The amount of the deformation of the specimen decreases with the propagation frequency of the incident wave. On the other hand, to improve accuracy at the strain and strain rate calculated by the one-dimensional stress wave theory, Young's modulus, the longitudinal wave speed, and the density were accurately determined. It was understood that the calculation value showed the strain and strain rate captured with the high-speed photography are a good agreement. As a result, the validity of the measurement accuracy of this SHB could be shown.

Rotating Instability in an Annular Cascade: Detailed Analysis of the Instationary Flow Phenomena

2013 ◽  
Vol 136 (6) ◽  
Author(s):  
Benjamin Pardowitz ◽  
Ulf Tapken ◽  
Robert Sorge ◽  
Paul Uwe Thamsen ◽  
Lars Enghardt
Keyword(s):  
Unsteady Flow ◽  
High Speed ◽  
Pressure Sensors ◽  
Rotating Stall ◽  
Operating Conditions ◽  
Tip Vortex ◽  
Pressure Waves ◽  
Flow Profile ◽  
Rotating Instability ◽  
Annular Cascade

Rotating instability (RI) occurs at off-design conditions in compressors, predominantly in configurations with large tip or hub clearance ratios of s* ≥3%. RI is the source of the blade tip vortex noise and a potential indicator for critical operating conditions like rotating stall and surge. The objective of this paper is to give more physical insight into the RI phenomenon using the analysis results of combined near-field measurements with high-speed particle image velocimetry (PIV) and unsteady pressure sensors. The investigation was pursued on an annular cascade with hub clearance. Both the unsteady flow field next to the leading edge as well as the associated rotating pressure waves were captured. A special analysis method illustrates the characteristic pressure wave amplitude distribution, denoted as “modal events” of the RI. Moreover, the slightly adapted method reveals the unsteady flow structures corresponding to the RI. Correlations between the flow profile, the dominant vortex structures, and the rotating pressure waves were found. Results provide evidence to a new hypothesis, implying that shear layer instabilities constitute the basic mechanism of the RI.

Three-dimensional analyses of two high-speed trains crossing on a bridge

2003 ◽  
Vol 217 (2) ◽  
pp. 99-110
Author(s):  
H-T Lin ◽  
S-H Ju
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
High Speed ◽  
Three Dimensional ◽  
Dynamic Effect ◽  
Response Ratio ◽  
Element Analysis ◽  
Dynamic Finite Element Analysis ◽  
High Speed Trains ◽  
The One

This paper investigates the dynamic characteristics of the three-dimensional vehicle-bridge system when two high-speed trains are crossing on a bridge. Multispan bridges with slender piers and simply supported beams were used in the dynamic finite element analysis. A response ratio (RR) was defined in this study to represent the ratio of the vehicle-bridge interaction of two-way trains to that of a one-way train. The finite element results indicate that this ratio increases significantly when two-way trains run near the same speed, and the maximum value is approximately equal to or smaller than two for the vertical dynamic response. This means that the maximum dynamic response of the two-way trains is at most twice that of the one-way train. When the two-way train speeds are sufficiently different, the response ratio approaches one on average, which means that the dynamic effect of the two-way train is similar to that of the one-way train. Finite element results also indicate that the averaged response ratio in the three global directions is about 1.65 when the two-way trains run at the same speed.

Amplification and attenuation of waves of finite duration by means of a bubble zone in the one-dimensional approximation

2012 ◽  
Vol 9 (2) ◽  
pp. 33-37
Author(s):  
M.N. Galimzyanov
Keyword(s):  
Solid Wall ◽  
Nonlinear Effects ◽  
Uneven Distribution ◽  
Pressure Waves ◽  
One Dimensional ◽  
Finite Duration ◽  
Dimensional Approximation ◽  
The One ◽  
Bubble Zone ◽  
As Effects

Some peculiarities of the dynamics of pressure waves in a fluid containing bubble zone of finite dimensions in the one-dimensional approximation are studied. The problem is considered taking into account nonlinear effects. The results of the action of wave pulses on a bubble area with an uneven distribution of bubbles are presented, as well as effects on a solid wall covered with a bubble area.

Research on One-Dimensional High Frequency Linear Motion Platform

2015 ◽  
Vol 734 ◽  
pp. 332-335
Author(s):  
Fei Wang ◽  
Rong Rong Wu ◽  
Li Qiang Wang ◽  
Si Yuan Wu
Keyword(s):  
High Frequency ◽  
High Speed ◽  
Voice Coil Motor ◽  
Design Solution ◽  
Mechanical Transmission ◽  
Linear Motion ◽  
Motion Platform ◽  
One Dimensional ◽  
The One ◽  
And Control

Precision motion system is driven directly by high frequency linear motion platform, eliminating the adverse effects brought by mechanical transmission, and greatly improving the rapid reaction capability and the control accuracy of feedback system. The linear motion platform is widely used in various types of high-speed, precision machining equipment. In the paper, the one-dimensional linear motion platform is described, and design solution of mechanical part and control system is also introduced, including working principle and structure of voice coil motor, control methods of grating sensors, circuit of grating sensor, drive and control circuit. Displacement control, speed control and output force control of the one-dimensional linear motion control platform can be achieved. So the one-dimensional linear motion platform can be applied in the movement device in high-precision and high-speed.

Sign in / Sign up

Export Citation Format

Share Document