Investigation on the aerodynamic characteristics of a hybrid braking system for trains

Abstract

The demand for high speed rail networks is rapidly increasing in newlinedeveloping countries like india. one of the major constraints in the design and newlineimplementation of the high speed train (hst) network is the braking newlineefficiency with minimum frictional losses and maintenance costs. recently, newlinethe concept of aerodynamic braking system (abs) from the airplane newlineapplications has inspired the hst railway coach designers and it has been newlineincorporated for a few bullet trains as a testing phase. the amount of newlinedeceleration and reduction in braking distance achieved through the abs is newlinecomparatively 10% to 15% higher than the conventional systems. however, newlinethe bullet trains are limited to several countries to connect major cities and in newlinemany developing nations the trains run through the speed range of 120 km/hr newlineto 180 km/hr only. the length of the train and rolling resistance also much newlinehigher than the bullet trains and the average braking distance simly exceeds newline500 m during standard operating conditions. hence, the braking performance newlineenhancement is extremely important to ensure the passenger safety newlinespecifically for the trains moving at the speed of more than 120 km/hr. newlinein the present work, an indian train configuration known as wap7 newline(wide gauge ac electric passenger, class 7) has been considered with the newlinelocomotive and one passenger car for the feasibility study of abs in the newlineexisting model. the demand for hst network has rapidly increased in newlinedeveloping countries like india and the need for superior emergency braking newlineis emphasized by national high speed rail corporation limited (nhsrcl) newlinein recent times. in indian railways, most of the trains operated with the newlineadhesive braking system that develops high friction between the wheels and newlinebrake shoes. hence, a high amount of heat is produced that causes thermal newlinedeformation as well. to overcome the problem, a non-adhesive braking newlinesystem such as abs is preferred for the hst. in abs, a high amount of air newlineresistance is created instantaneously by opening a spoiler over the train to newlineamplify t