Aerodynamic Simulation of High Speed Container Flat Wagon

2011 ◽  
Vol 52-54 ◽  
pp. 1614-1619
Author(s):  
Dan Tian ◽  
Ji Min Zhang ◽  
Yong Qiang Wang
Keyword(s):  
Flow Field ◽  
Surface Pressure ◽  
High Speed ◽  
Aerodynamic Resistance ◽  
Flow Analysis ◽  
External Flow ◽  
Size Difference ◽  
Pressure Drag ◽  
Pressure Distributions ◽  
Aerodynamic Simulation

Through the external flow analysis of 200 km/h high-speed container flat wagon utilizing SST k- turbulence model, we got the surface pressure distributions, flow field, locomotive resistance, containers resistance and so on. The researches show that pressure drag dominates large resistance of high-speed container flat wagon; the size difference between locomotive and container as well as the gap between vehicles will complex the flow in return increase the total aerodynamic resistance of train; due to the influence of bottom flow, the pressure drag of middle container with bogies is smaller than without, but still large.

scholarly journals Numerical Analysis and Characterization of Surface Pressure Fluctuations of High-Speed Trains Using Wavenumber–Frequency Analysis

2019 ◽  
Vol 9 (22) ◽  
pp. 4924
Author(s):  
Lee ◽  
Cheong ◽  
Kim ◽  
Kim
Keyword(s):  
Flow Field ◽  
Open Field ◽  
Frequency Analysis ◽  
Surface Pressure ◽  
High Speed ◽  
Pressure Fluctuations ◽  
Interior Noise ◽  
High Speed Train ◽  
Pressure Fields ◽  
Time Space

The high-speed train interior noise induced by the exterior flow field is one of the critical issues for product developers to consider during design. The reliable numerical prediction of noise in a passenger cabin due to exterior flow requires the decomposition of surface pressure fluctuations into the hydrodynamic (incompressible) and the acoustic (compressible) components, as well as the accurate computation of the near aeroacoustic field, since the transmission characteristics of incompressible and compressible pressure waves through the wall panel of the cabin are quite different from each other. In this paper, a systematic numerical methodology is presented to obtain separate incompressible and compressible surface pressure fields in the wavenumber–frequency and space–time domains. First, large eddy simulation techniques were employed to predict the exterior flow field, including a highly-resolved acoustic near-field, around a high-speed train running at the speed of 300 km/h in an open field. Pressure fluctuations on the train surface were then decomposed into incompressible and compressible fluctuations using the wavenumber–frequency analysis. Finally, the separated incompressible and compressible surface pressure fields were obtained from the inverse Fourier transform of the wavenumber–frequency spectrum. The current method was illustratively applied to the high-speed train HEMU-430X running at a speed of 300 km/h in an open field. The results showed that the separate incompressible and compressible surface pressure fields in the time–space domain could be obtained together with the associated aerodynamic source mechanism. The power levels due to each pressure field were also estimated, and these can be directly used for interior noise prediction.

Improving Startup Behavior of Fluid Couplings Through Modification of Runner Geometry: Part I—Fluid Flow Analysis and Proposed Improvement

2000 ◽  
Vol 122 (4) ◽  
pp. 683-688 ◽  
Author(s):  
H. Huitenga ◽  
N. K. Mitra
Keyword(s):  
Flow Field ◽  
High Speed ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Operation Condition ◽  
Three Dimensional Flow ◽  
Economical Design ◽  
Hydrodynamic Coupling ◽  
Turbine Runner ◽  
Fluid Flow Analysis

For the use as a startup device the characteristic of a hydrodynamic coupling has to be steep at the nominal high speed operation condition and flat in the range of lower speed ratios. The economical design of the runner requires that the mass and the volume of the coupling should be as small as possible. The flow field in a starting configuration is simulated and a detailed analysis of the three-dimensional flow field is performed to deduce constructional modifications which meet both requests. The analysis shows that several modifications on pump and turbine runner seem to be successful. The consequences of the variation of the runner geometries will be discussed in detail in Part II of this paper. [S0098-2202(00)02104-0]

scholarly journals Comparative Analysis of Surface Pressure Fluctuations of High-Speed Train Running in Open-Field and Tunnel Using LES and Wavenumber-Frequency Analysis

2021 ◽  
Vol 11 (24) ◽  
pp. 11702
Author(s):  
Songjune Lee ◽  
Cheolung Cheong ◽  
Byunghee Kim ◽  
Jaehwan Kim
Keyword(s):  
Open Field ◽  
Surface Pressure ◽  
High Speed ◽  
Pressure Field ◽  
Pressure Fluctuations ◽  
External Flow ◽  
High Speed Train ◽  
Wall Panel ◽  
Mean Flow ◽  
The Mean

The interior noise of a high-speed train due to the external flow disturbance is more than ever a major problem for product developers to consider during a design state. Since the external surface pressure field induces wall panel vibration of a high-speed train, which in turn generates the interior sound, the first step for low interior noise design is to characterize the surface pressure fluctuations due to external disturbance. In this study, the external flow field of a high-speed train cruising at a speed of 300 km/h in open-field and tunnel are numerically investigated using high-resolution compressible LES (large eddy simulation) techniques, with a focus on characterizing fluctuating surface pressure field according to surrounding conditions of the cruising train, i.e., open-field and tunnel. First, compressible LES schemes with high-resolution grids were employed to accurately predict the exterior flow and acoustic fields around a high-speed train simultaneously. Then, the predicted fluctuating pressure field on the wall panel surface of a train was decomposed into incompressible and compressible ones using the wavenumber-frequency transform, given that the incompressible pressure wave induced by the turbulent eddies within the boundary layer is transported approximately at the mean flow and the compressible pressure wave propagated at the vector sum of the sound speed and the mean flow velocity. Lastly, the power levels due to each pressure field were computed and compared between open-field and tunnel. It was found that there is no significant difference in the power levels of incompressible surface pressure fluctuations between the two cases. However, the decomposed compressible one in the tunnel case is higher by about 2~10 dB than in the open-field case. This result reveals that the increased interior sound of the high-speed train running in a tunnel is due to the compressible surface pressure field.

Modeling Design of Airborne Evaporation Cycle System

2014 ◽  
Vol 687-691 ◽  
pp. 455-458
Author(s):  
Yin Sai Guo ◽  
Yi Zhang ◽  
Ming Ke Cheng
Keyword(s):  
Numerical Analysis ◽  
Flow Field ◽  
Surface Pressure ◽  
Design Method ◽  
System Modeling ◽  
Aerodynamic Characteristics ◽  
External Flow ◽  
Appearance Modeling ◽  
Cycle System ◽  
Surface Pressure Distribution

A industrial design method based the numerical analysis is proposed to meet appearance modeling of airborne evaporation cycle system. The model is analyzed by using FLUENT. It better simulates the external flow field, gets the surface pressure distribution and velocity distribution of the flow field, and determines the aerodynamic characteristics of the system, which provides a new way for system modeling design.

An Investigation of Nucleating Flows of Steam in a Cascade of Turbine Blading-Theoretical Treatment

1995 ◽  
Vol 117 (1) ◽  
pp. 138-144 ◽  
Author(s):  
F. Bakhtar ◽  
M. R. Mahpeykar ◽  
K. K. Abbas
Keyword(s):  
Flow Field ◽  
Surface Pressure ◽  
Integral Method ◽  
Main Flow ◽  
Theoretical Treatment ◽  
Viscous Effects ◽  
Pressure Distributions ◽  
Time Marching ◽  
Overall Efficiency ◽  
Turbine Blading

This paper describes the theoretical part of an investigation into nucleating flows of steam in a cascade turbine nozzle blading. The main flow field is regarded as inviscid and treated by the time-marching technique. The viscous effects are assumed to be concentrated in boundary layers which are treated by the integral method. The agreement obtained with the observed surface pressure distributions and overall efficiency measurements is very good.

Design of High-Speed Magnetic Centrifugal Blower Impeller and Numerical Simulation of Internal Flow Field

2012 ◽  
Vol 150 ◽  
pp. 154-159
Author(s):  
Zhao Kui Wang ◽  
Shu Qin Liu ◽  
Hong Wei Li ◽  
Bin Bian
Keyword(s):  
Flow Field ◽  
High Speed ◽  
Magnetic Levitation ◽  
Flow Analysis ◽  
Calculated Data ◽  
Simple Algorithm ◽  
Internal Flow ◽  
Centrifugal Fan ◽  
Design Data ◽  
Low Efficiency

Currently, most domestic blower speed is still in 3000r/min level. The friction loss of mechanical bearings results in their low efficiency. To further improve the efficiency of the fan, a new high-speed maglev centrifugal fan was developed specially. The design of impeller styles, structure and size are rational. 3D graphics of the impeller and volute were drawn by using solidworks software. Application of CFD flow analysis software and the SIMPLE algorithm described viscous flow field within the three-dimensional centrifugal fan. By comparing simulation data with calculated data, optimize the turbine design. The simulative results are basically consistent with the design data, which provides a theoretical basis for the design of a new high-speed magnetic levitation fans, improving the level of centrifugal fan design.

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