fa Railway track and structures Railway track and structures پژوهشي Research Speed is the created air flow as well as slipstream effects as the trains move. These effects can have some level of impact on fuel and energy efficiency  of  the  train,  but  their  other  important  outcome  is  the emergence of turbulent flows at higher speeds which can cause aerodynamic  drag  forces  followed  by  noise  and  vibration.  Thus, slipstream effects have significant importance in the design of trackside installations and necessitate unique safety measures. A high-speed train passing   under   a   structure   or   object   makes   sudden   impacts   on aerodynamic forces acting on that object.  So this issue needs to be considered in the design of structures and installations to be built around high-speed rails. In this study, a numerical simulation with moving mesh and k-epsilon turbulence model was carried out in FLUENT software in order to investigate the aerodynamic and the slipstream effects for a high-speed train in motion on overhead and trackside installations with the   objective   of   preventing   aerodynamics-induced   damage.   This simulation was conducted in two scenarios of absence and presence of aerodynamic brake on topside of the train. In the end, ABAQUS finite element software was used to determine the maximum stress exerted on objects (installations) positioned at different distances from the rail, and the results were compared with the maximum allowable stresses to determine a minimum permissible distance between installations and high-speed train. Train aerodynamics, Drag force, Moving mesh, Slipstream, High speed train 49 62 http://ijrare.iust.ac.ir/browse.php?a_code=A-10-82-3&slc_lang=fa&sid=1 Vahid Sarafrazi 180031947532846001443 180031947532846001443 No School of railway Eng., Iran University of Science and Technology Tehran, Iran School of railway Eng., Iran University of Science and Technology Tehran, Iran Mohammad Reza Talaee mrtalaee@iust.ac.ir 180031947532846001444 180031947532846001444 Yes School of railway Eng., Iran University of Science and Technology Tehran, Iran School of railway Eng., Iran University of Science and Technology Tehran, Iran