期刊名称：International Journal of Innovative Research in Science, Engineering and Technology
印刷版ISSN：2347-6710
电子版ISSN：2319-8753
出版年度：2014
卷号：3
期号：8
页码：15439
DOI：10.15680/IJIRSET.2014.0308051
出版社：S&S Publications
摘要：Velocity of projectiles plays an important role in determining the response and behaviour of a targetunder impact. In this project metallic canister with a soft projectile, which is one of the critical dynamic components, isused to launch bird/ice pellet, to study its influence on the behaviour of aircraft and aero-engine parts. This is done byusing conventional compressed air launcher which launches the projectile velocities up to 200 m/s. The canisters whichhouse the test projectile collapse against canister arrester located at the delivery end of the launcher. The collapsecharacteristics of the canisters are dependent on the geometry of the tip of the arresters, material of the canisters, theshape of the canisters and the heat treatment process adapted for canisters. The impact load of the canister on thearrester can be up to several tonnes axially. This force is a function of the collapsibility of the canister at impact and inturn it is determined by the operating pressure of the launcher. It is therefore necessary to develop a velocity measuringsystem, which determines the dynamic axial loads on the launcher as well as the target plate, which in turn helps instudying the collapsibility parameter of the canister itself.In order to measure the high velocity of the projectile three measuring devices, namely, optical laser sensor,based on programmable logic device, copper wire and graphite rod based devices are developed and used. To provideadequate redundancy for the complex, highly dynamic and costly impact tests, two of these three velocity measuringdevices are used simultaneously: (1) copper wire based sensing system and (2) graphite rod based sensing system. Themeasuring device input parameter is fabricated on a gun barrel with acrylic fixture at two positions at a distance of 1 mbefore the arrester where the canister strikes and collapses. At initial and final position, optical transmitter and receivergive the delay time when the canister passes through it by obstructing the sensing signal path. The copper wire circuitbased device gives open circuit delay between the two points when canister breaks it. The time taken to travel 1mdistance by the canister in the gun barrel is obtained from the device and the velocity of the canister or projectile isexperimentally evaluated.
