Numerical Study of the Unsteady Aerodynamic Performance of Two Maglev Trains Passing Each Other in Open Air Using Different Turbulence Models

Xianli Li,Dan Zhou,Siniša Krajnovic

doi:10.3390/app112411894

Xianli Li, Dan Zhou + Show 1 more

Open Access

https://doi.org/10.3390/app112411894

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Abstract

The strong change in the flow fields around two maglev trains (MTs) passing each other in open air may affect their manoeuvrability and passengers’ comfort. In this study, we evaluated the aerodynamic performance of two MTs passing each other via shear stress transport (SST) k–ω model and improved delayed detached eddy simulations based on the Spalart–Allmaras model (SA−IDDES) and the SST k–ω model (SST−IDDES). The accuracy of the numerical simulation method was verified using experimental data acquired from a moving model test. The results showed that the difference in the amplitude of the transient pressure obtained with the different turbulence models was less than 5%. The wake vortex structures on the intersection side were found to interact, and their intensity consequently decreased. The SST−IDDES model produced smaller-scale vortices than the SA−IDDES model, particularly in the near-wake region. There were large differences in the drag and lift forces obtained using the different turbulence models. Among them, the lift force of the tail car was more sensitive to the turbulence model, and its maximum value obtained with the SST−IDDES model was 11% larger than that obtained with the SA−IDDES model.

Highlights

It is common for trains travelling along a double-track railway line in open air to pass each other
It was found that parameters including the train speed, line spacing, nose shape, and marshalling length affect the aerodynamic performance of the passing trains
The height h obtained with the stress transport (SST)−IDDES model is 10% greater than that obtained with the SA−IDDES model, and the shortest and longest distances w of the two vortex cores are obtained with the SST−IDDES and SA−IDDES, respectively, with a difference of 10.3%

Summary

Introduction

It is common for trains travelling along a double-track railway line in open air to pass each other. A lateral aerodynamic force is generated during this process, causing the trains to shake. The aerodynamic performance of the two trains passing each other in crosswinds was investigated in detail [10,11]. The aforementioned studies mainly focused on the aerodynamic performance of two HSTs passing each other in open air. The surrounding flow of two trains passing each other in open air is different from that of a single train moving in. Wake flows when a single train runs in open air have been investigated [17,18,19]. The srimemualaitneddebryotfhtehSisSTpakp–ωer, iSsAo−rgIDanDiEseSd, aansdfSoSllTo−wIsD: DSeEcStimonet2hoidnstraonddutcoesretvheealmtheethfloodwology, mogsiapefenneneotcchrdsmlhiiuimtsmaeidvntpeireiianntyssypgtmh;maetSlssrhoeeviaedcsnartegsooliiloieurd,tgnoincavamod3tinimtoepiytswtnrp;ere,Sduyostetermatacanrsttantoiifsoiosdonnnitlesehlalon3epl,wtcadnpopssoursm:remmieSsnpseeaegsucniruntiettic,arsaoaetncntli,hhuorv2eenmoesiatnnlueholturledrctimosrciotadaaymelunlropscadienceritanogasuln,ftpainhral,eeelduysmsommus,ueiwlseetsb,tsrhalhiieknacoganectderlldfunoaslcledeoaokrtwinguan.aytsgpTil,,oy,hieannmsexnic,psredla,euesnmriadhnidemiagcnrmileoegnunndeddtethsyeairhennrlagatimoexnic-, vfaolridcea;tiaonnd, tSraenctsiioennt4ppreresssuenret,svtehleocciotyncplurosfiiolenss,.wake flows, and aerodynamic force; and Section 4 presents the conclusions

Methodology

Mesh Generation

Wake Flows

Findings

Conclusions