Investigation on the effect of abrasive waterjet parameter on machining stainless steel

Abrasive waterjet machining (AWJM) can perform various machining operations on almost any material including hard to machine materials. However, performance of a process depends on the chosen set of parameters. AWJM has major parameters such as traverse rate, water pressure, standoff distance and abrasive flowrate that will affect its performance. The present study investigates the effects of AWJM parameters (i.e. traverse rate, water pressure and standoff distance) on the width, depth and roughness of a channel produced at the surface of stainless steel. The results showed that by reducing the standoff distance and water pressure, the width of the channel was also reduced. For channel depth, increasing traverse rate produced a shallower channel depth. In contrast, increasing the water pressure produced a deeper channel depth. The surface roughness of the channel showed significant improvement by reducing the water pressure at a lower traverse speed and standoff distance. A proper selection of parameters is required in order to produce a suitable channel during AWJM surface texturing process

Sound Insertion Loss of Kenaf and Arenga Pinnata

Abstract Heat Ventilation Air Conditioning System (HVAC) is designed to control the environment inside of residential, commercial or industrial buildings by controlling temperature of a room through heating and cooling. However, due to its mechanism, noise is produced in the system and reaches the people inside the building, thus causing distraction, discomfort and uneasiness. There are HVAC silencers in the market; however, the sound absorbing material used is of mineral wool types. In this study, the ducting silencer with the sound absorptive material that made of Arenga Pinnata, Kenaf and composition of these both materials were tested to identify its performance. The experiment was carried out in a testing apparatus that follows the ASTM E477-99 standard. Insertion loss was analysed at the end of the study. From the overall result and comparison, the insertion loss of Kenaf is averagely better than Arenga Pinnata, that is 97.5% higher than Arenga Pinnata. When composition of Arenga Pinnata and Kenaf is used, Kenaf plays important role in sound insertion loss, where when Kenaf composition increase, it increases the sound insertion loss capability.</jats:p