Numerical Investigation on Load Transfer Effects in Bogies of Urban Rail Vehicles

2006 ◽  
Author(s):  
Roberto Corradi ◽  
Alan Facchinetti ◽  
Giovanni Sempio
Keyword(s):  
Numerical Simulation ◽  
Numerical Investigation ◽  
Dynamic Behaviour ◽  
Load Transfer ◽  
Transfer Effects ◽  
Coupling Effects ◽  
Lateral Dynamics ◽  
Rail Vehicles ◽  
Urban Rail ◽  
Coupling Phenomena

Urban rail vehicles can present many types of architecture, definitely different from those of traditional rail vehicles. When dealing with long articulated tramcars, complex coupling effects between the vertical and lateral dynamics may arise. Making reference to a modern tramcar, the coupling phenomena are investigated in detail by means of numerical simulation, considering the dynamic behaviour during the negotiation of curves with or without superelevation.

NUMERICAL INVESTIGATION OF FILM DISTRIBUTION IN HORIZONTAL-TUBE FALLING FILM EVAPORATOR

2011 ◽  
Vol 19 (03) ◽  
pp. 177-183 ◽  
Author(s):  
JIN-BO CHEN ◽  
QING-GANG QIU
Keyword(s):  
Numerical Simulation ◽  
Fluid Flow ◽  
Film Thickness ◽  
Liquid Film ◽  
Numerical Investigation ◽  
Horizontal Tube ◽  
Flow Density ◽  
Falling Film ◽  
Film Distribution ◽  
Simulation Results

The technique of horizontal-tube falling film has been used in the cooling and heating industries such as refrigeration systems, heating systems and ocean thermal energy conversion systems. The comprehensive performance of evaporator is directly affected by the film distribution characteristics outside tubes. In this paper, numerical investigation was performed to predict the film characteristics outside the tubes in horizontal-tube falling film evaporator. The effects of liquid flow rate, tube diameter and the circular degree of tube on the film thickness were presented. The numerical simulation results were compared with that of the empirical equations for calculating the falling film thickness, and agreements between them were reasonable. Numerical simulation results show that, at the fixed fluid flow density, the liquid film is thicker on the upper and lower tube and the thinnest liquid film appears at angle of about 120°. The results also indicate that, when the fluid flow density decreases to a certain value, the local dryout spot on the surface of the tube would occur. In addition, the film thickness decreases with the increases of the tube diameter at the fixed fluid flow density.

scholarly journals The dynamic behaviour of Archimede’s Bridges: Numerical simulation and design implications

2010 ◽  
Vol 4 ◽  
pp. 91-98 ◽  
Author(s):  
Federico Perotti ◽  
Gianluca Barbella ◽  
Mariagrazia Di Pilato
Keyword(s):  
Numerical Simulation ◽  
Dynamic Behaviour

A Numerical Investigation on the Volute/Diffuser Interaction due to the Axial Distortion at Impeller Exit

2000 ◽  
Author(s):  
Fahua Gu ◽  
Abraham Engeda ◽  
Mike Cave ◽  
Jean-Luc Di Liberti
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Numerical Investigation ◽  
Steady Flow ◽  
Centrifugal Compressor ◽  
Vortex Structure ◽  
Flow Model ◽  
Single Stage ◽  
Mass Flows

Abstract A numerical simulation is performed on a single stage centrifugal compressor using the commercially available CFD software, CFX-TASCflow. The steady flow is obtained by circumferentially averaging the exit fluxes of the impeller. Three runs are made at design condition and off-design conditions. The predicted performance is in agreement with experimental data. The flow details inside the stationary components are investigated, resulting in a flow model describing the volute/diffuser interaction at design and off-design conditions. The recirculation and twin vortex structure are found to explain the volute loss increase at lower and higher mass flows, respectively.

A Study on the Characteristics of Bogie Frame Materials

2013 ◽  
Vol 420 ◽  
pp. 144-148 ◽  
Author(s):  
Sung Cheol Yoon ◽  
Yeon Su Kim ◽  
Joon Hyung Ryu ◽  
Sung Hyuk Park ◽  
Geun Soo Park
Keyword(s):  
Structural Analysis ◽  
Performance Test ◽  
Structural Safety ◽  
Combined Stress ◽  
Bogie Frame ◽  
Test Standards ◽  
Rail Vehicles ◽  
Urban Rail ◽  
Load Tests ◽  
And Performance

This paper describes the structural analysis, load tests and combined stress of the bogie frame. It seeks to identify the structural safety of the bogie frame when the bogie is assembled on the train and a train service is implemented. The bogie consists of the bogie frame, suspension, wheels, brakes and transmission, etc. The bogie frame can be considered as the most important part of the bogie. The analysis and tests were evaluated using JIS E 4207 standards and performance test standards for urban rail vehicles.

Numerical Simulation of Thermal and Fluid-Dynamic Behaviour of Reciprocating Compressor

2000 ◽  
Author(s):  
Zhilong He ◽  
Xueyuan Peng ◽  
Pengcheng Shu
Keyword(s):  
Numerical Simulation ◽  
Fluid Flow ◽  
Heat Balance ◽  
Dynamic Behaviour ◽  
Fluid Dynamic ◽  
Reciprocating Compressor ◽  
One Dimensional ◽  
Compressor Design ◽  
Suction Line ◽  
Hermetic Compressor

Abstract This paper presents a numerical method for simulating the thermal and fluid-dynamic behavior of hermetic compressors in the whole compressor domain. The model of fluid flow is developed by integrating transient one-dimensional conservation equations of continuity, momentum and energy through all of the elements from suction line to discharge line. The model describing thermal behavior is based on heat balance in the components such as muffler, connecting tubes and orifices. The calculation of the thermodynamic and transport properties for different refrigerants at various conditions has been considered, and some numerical results for a hermetic compressor are presented. The present study has demonstrated that the numerical simulation is a fest and reliable tool for compressor design.

Numerical investigation of the monotonic drained lateral behaviour of large diameter rigid piles in medium dense uniform sand

Géotechnique ◽  
2021 ◽  
pp. 1-39
Author(s):  
Huan Wang ◽  
M. Fraser Bransby ◽  
Barry M. Lehane ◽  
Lizhong Wang ◽  
Yi Hong
Keyword(s):  
Numerical Investigation ◽  
Load Transfer ◽  
Large Diameter ◽  
Offshore Wind ◽  
Soil Pressure ◽  
Lateral Capacity ◽  
Pile Diameter ◽  
Centrifuge Tests ◽  
Lateral Response ◽  
Loading Eccentricity

This paper presents a numerical investigation of the monotonic lateral response of large diameter monopiles in drained sand with configurations typical of those employed to support offshore wind turbines. Results from new centrifuge tests using instrumented monopiles in uniform dry sand deposits are first presented and used to illustrate the suitability of an advanced hypoplastic constitutive model to represent the sand in finite element analyses of the experiments. These analyses are then extended to examine the influence of pile diameter and loading eccentricity on the lateral response of rigid monopiles. The results show no dependency of suitably normalized lateral load transfer curves on the pile diameter and loading eccentricity. It is also shown that, in a given uniform sand, the profile with depth of net soil pressure at ultimate lateral capacity is independent of the pile diameter because of the insensitivity of the depth to the rotation centre for a rigid pile. A normalization method is subsequently proposed which unifies the load-deflection responses of different diameter rigid piles at a given load eccentricity.

Numerical Simulation of Pressure Loss and Heat Transfer Characteristics for Additively Manufactured Channels

2020 ◽  
Author(s):  
Bryan Arko ◽  
Chad Iverson ◽  
Nicholas Staudigel
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Surface Roughness ◽  
Nusselt Number ◽  
Pressure Loss ◽  
Reynolds Numbers ◽  
Measured Data ◽  
Transfer Effects ◽  
Micro Channels ◽  
Heat Transfer Effects

Abstract This body of work provides an initial study of modeling both surface roughness and heat transfer concurrently in a numerical simulation of micro-channels representative of those that might be found in a turbine cooling application. Increased use of additive manufacturing (AM) or 3D printing techniques for turbomachinery components enable the manufacture of complex features to achieve higher operational performance. Accurate modeling of flow losses and heat transfer effects are critical to designing parts which achieve optimal efficiency paired with durability. Surface finish is rougher with AM compared to more traditional manufacturing techniques; therefore enhancing the pressure loss and heat transfer effects. Proper implementation of surface roughness within the computational model and correct modeling of the near wall boundary mesh must be maintained to produce accurate results. This study focuses on the comparison of near wall mesh treatment coupled with surface roughness to determine a practice for obtaining accurate pressure loss and heat transfer within a cooling passage, as compared to measurements. Steady-state computational fluid dynamics (CFD) models consisting of a wind tunnel inlet nozzle and outlet diffuser, along with internal cooling passages represented using micro-channels, has been run for a range of Reynolds numbers and simulated roughness levels. Analysis of a baseline configuration with aerodynamically smooth walls is first compared to the measured data to verify the assumption of aerodynamically smooth walls. Surface roughness is then added to the channel walls, from published test coupon measurements, and compared to published experimental data for a range of Reynolds numbers. The metal surrounding the passages is also included as a conjugate heat transfer model providing heat addition to the fluid. Pressure loss and heat transfer is compared to the measured data as a friction factor and Nusselt number for the range of Reynolds numbers. Since surface roughness units and measurements vary, an effect of surface roughness values on pressure loss and heat transfer will also be investigated to determine the importance of using and converting to the correct units for the numerical model. This serves as a starting point for a guideline that will help when both heat transfer and surface roughness are included in a CFD model. Further study is recommended to understand the diminishing levels of increase in friction factor and Nusselt number observed as surface roughness was continually increased in the numerical simulation.

Numerical Simulation on the Flow Control by Mounting Indented Gurney Flaps for a Wind Turbine

2012 ◽  
Vol 512-515 ◽  
pp. 623-627 ◽  
Author(s):  
Wan Li Zhao ◽  
Xiao Lei Zheng
Keyword(s):  
Numerical Simulation ◽  
Wind Turbine ◽  
Numerical Investigation ◽  
Wind Turbines ◽  
Aerodynamic Performance ◽  
Optimal Position ◽  
Gurney Flaps ◽  
Turbine Performance ◽  
Gurney Flap ◽  
Practical Engineering

Numerical investigation of large thick and low Reynolds airfoil of wind turbines by mounting indented Gurney flaps was carried out. The influenced rules of the position of Gurney flaps on the aerodynamic performance of airfoil under same height of flaps were achieved, and the optimal position of Gurney flap was presented. At last, the mechanism of wind turbine performance controlled by Gurney flap was discussed. The results can provide the theoretical guidance and technical support to wind turbines control in practical engineering.

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