Abstract
In the development of dry ice blasting nozzle geometry, the critical process parameters depend on particle jet velocity. However, very few researchers have attempted sensitivity on the velocity flow area of specific nozzle geometric parameters. A numerical simulation approach was performed in this paper using Ansys Fluent to investigate different nozzle parameters on the velocity flow field. A two-dimensional model is solved iteratively using averaged Navier-Stokes under Eulerian flow description. It was found that the velocity value increases that reach 550 m/s with an increment of the nozzle area ratio of up to 20 without influencing convergent angle and the velocity magnitude drop linearly from 525 m/s to 505 m/s in with the rise of divergent length that swell up to 700 mm and with constant convergent angle and convergent length.
Abstract
The critical process parameters in manufacturing dry ice blasting nozzle geometry directly related to particle jet velocity. Many studies focused on its performance without considering the noise emission due to high operating pressure. This paper, a numerical simulation study was performed using Ansys Fluent to investigate the effect of nozzle geometry of single-hose dry ice blasting on the acoustic power level. The process of modelling the two-way mass momentum and energy exchange between two phases was successfully solved iteratively in the two-way mass momentum model and the energy exchange between the two phases. It was found that the value of noise emission reaches a maximum level when the shortest convergent angle of 20° with a minimal convergent length of 50 mm and a maximum length of 300 mm is introduced. Besides, the peak value of acoustic power level swell up to 146 dB occurs at a nozzle area ratio of 20 without influencing by convergent angle and extending the divergent length highly influencing noise reduction as less than 143.5 dB for a divergent length of 700 mm.
Velocity Flow Field Characteristic on Nozzle Cavity using Central Composite Design of Computational Method for Dry Ice Blasting System