scholarly journals Response Surface Analysis of DIB Nozzle Geometry on Acoustic Power Level using Central Composite Design of Experiment

2021 ◽  
Vol 2129 (1) ◽  
pp. 012019
Author(s):  
Mohamad Nur Hidayat Mat ◽  
Md Faisal Md Basir ◽  
Nor Zelawati Asmuin
Keyword(s):  
Energy Exchange ◽  
Power Level ◽  
Maximum Level ◽  
Acoustic Power ◽  
Nozzle Geometry ◽  
Operating Pressure ◽  
Noise Emission ◽  
Dry Ice ◽  
Two Phases ◽  
Dry Ice Blasting

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.

Optimizing nozzle convergent angle using central composite design on the particle velocity and acoustic power level for single-hose dry ice blasting nozzle

2020 ◽  
Author(s):  
Mohamad Nur Hidayat Mat ◽  
Nor Zelawati Asmuin ◽  
Md Faisal Md Basir ◽  
Mohammad Reza Safaei ◽  
Mohd Shareduwan Mohd Kasihmuddin ◽  
...  
Keyword(s):  
Central Composite Design ◽  
Particle Velocity ◽  
Power Level ◽  
Acoustic Power ◽  
Dry Ice ◽  
Dry Ice Blasting ◽  
Central Composite

Analysis of the Sound Power Level Emitted by Portable Electric Generators (Outdoor Powered Equipment) Depending on Location and Measuring Surface

2013 ◽  
Vol 430 ◽  
pp. 266-275 ◽  
Author(s):  
Elena Postelnicu ◽  
Valentin Vladut ◽  
Cristian Sorica ◽  
Petru Cardei ◽  
Ion Grigore
Keyword(s):  
Noise Source ◽  
Power Level ◽  
Acoustic Power ◽  
Sound Power ◽  
Noise Emission ◽  
Sound Power Level ◽  
Measuring Surface ◽  
Measurement Surface ◽  
Electric Generators

Acoustic power is a measure which must be specified on the outdoor used equipments and its determination depends on several factors: the place where the equipment works (indoor or outdoor), the placement of the microphones for its determination (the distance less or greater from the noise source), the shape of the measurement surface (parallelepiped or hemispherical). This paper aims to analyze the values obtained in these situations and interpret the data to determine the influence that each factor has on the acoustic power compared with the values obtained (permissible) according to Directive regarding noise emission D 2000/14/EC.

Influence of divergent length on the gas-particle flow in dual hose dry ice blasting nozzle geometry

2020 ◽  
Vol 364 ◽  
pp. 152-158 ◽  
Author(s):  
Mohamad Nur Hidayat Mat ◽  
Nor Zelawati Asmuin ◽  
Md Faisal Md Basir ◽  
Marjan Goodarzi ◽  
Muhammad Faqhrurrazi Abd Rahman ◽  
...  
Keyword(s):  
Particle Flow ◽  
Nozzle Geometry ◽  
Dry Ice ◽  
Dry Ice Blasting

scholarly journals Velocity Flow Field Characteristic on Nozzle Cavity using Central Composite Design of Computational Method for Dry Ice Blasting System

2021 ◽  
Vol 2129 (1) ◽  
pp. 012020
Author(s):  
Mohamad Nur Hidayat Mat ◽  
Md Faisal Md Basir ◽  
Mohamad Farid Sies
Keyword(s):  
Flow Field ◽  
Computational Method ◽  
Nozzle Geometry ◽  
Navier Stokes ◽  
Flow Area ◽  
Ansys Fluent ◽  
Dry Ice ◽  
Velocity Magnitude ◽  
Velocity Flow ◽  
Dry Ice Blasting

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.

Industrial use of dry ice blasting in surface cleaning

2021 ◽  
pp. 129630
Author(s):  
Vítězslav Máša ◽  
David Horňák ◽  
Dalimil Petrilák
Keyword(s):  
Surface Cleaning ◽  
Dry Ice ◽  
Industrial Use ◽  
Dry Ice Blasting

scholarly journals A simulation of traffic noise emissions at a roundabout based on a cellular automaton model

Acta Acustica ◽  
2021 ◽  
Vol 5 ◽  
pp. 42
Author(s):  
Canyi Du ◽  
Xinfa Qiu ◽  
Feng Li ◽  
Ming Cai
Keyword(s):  
Cellular Automaton ◽  
Road Traffic ◽  
Power Level ◽  
Traffic Noise ◽  
Traffic Volume ◽  
Sound Power ◽  
Noise Emission ◽  
Urban Road ◽  
Speed Distribution ◽  
Sound Power Level

The calculation and evaluation of traffic noise is an important task in urban road design. Roundabouts are a common form of urban road intersection. The complexity of traffic operations makes the calculation of traffic noise near a roundabout challenging. To explore traffic noise at roundabouts, a cellular automaton traffic flow model for a two-lane roundabout is established. Based on this model, a dynamic simulation method for traffic noise at roundabouts is proposed. The traffic operation and noise emissions at a roundabout are simulated. The vehicle speed distribution and traffic noise distribution at the roundabout are analysed, and the relationship between the traffic volume and sound power level of the cells is discussed. Finally, the proposed method is compared with existing traffic noise models, and the accuracy and efficiency of the proposed method are verified. The results of this paper show that the speed distribution and noise emission distribution at the roundabout are not uniform. When the traffic volume increases to saturation, the noise emission on the ring road will not keep increasing, and the sound power level of the cells on the inner ring is approximately 2 dBA higher than that of the outer ring. The methods and results in this paper may be valuable for road traffic design and noise control.

scholarly journals Quiet! Okay, But How?

1999 ◽  
Vol 121 (04) ◽  
pp. 70-71
Author(s):  
M.A. Zaher
Keyword(s):  
Occupational Safety ◽  
Power Level ◽  
Noise Pollution ◽  
The United States ◽  
Operating Pressure ◽  
Air Velocity ◽  
Sound Power Level ◽  
Conflicting Demands ◽  
Safety And Health ◽  
Pneumatic Tool

This article focuses on pneumatic tools that are among the most damaging sources of noise pollution. The National Institute for Occupational Safety and Health estimates that more than 30 million workers in the United States are exposed to hazardous noise, costing the economy about $1 billion every year. There is no magic solution to all noise control problems, and this remains true even when we are dealing just with pneumatic tools. Each case must be considered separately, and the solution to be used must satisfy the often conflicting demands of at least five criteria simultaneously. The sound power level produced by a pneumatic tool is a product of many interrelated parameters: operating pressure, pressure drop, expansion volume, exhaust air velocity, speed of device, exhaust air, airflow, length of exhaust path, and tool power. Good standards are available for evaluating the noise of many components, and suppliers provide data on their products that can be used for comparison.

scholarly journals Supersonic Windtunnel Noise Attenuation

2021 ◽  
Author(s):  
William Wai Lim Wong
Keyword(s):  
Wind Tunnel ◽  
Sound Pressure Level ◽  
Noise Level ◽  
Sound Pressure ◽  
Power Level ◽  
Mesh Size ◽  
Acoustic Power ◽  
Pressure Level ◽  
Supersonic Wind Tunnel ◽  
Acoustic Treatment

The aerodynamic generated noise in the supersonic wind tunnel during operation at Ryerson University has exceeded the threshold of hearing damage. An acoustic silencer was to be designed and added to the wind tunnel to reduce the noise level. The main sources of noise generated from the wind tunnel with the silencer were identified to be located at the convergent divergent nozzle and the turbulent region downstream of the shock wave at the diffuser with the maximum acoustic power level of the entire wind tunnel at 161.09 dB. The designed silencer provided an overall sound pressure level reduction of 21.41 db which was considered as acceptable. Refinement to the mesh size and changes to the geometry of the mixing chamber was suggested for a more accurate result in noise output as well as flow conditions would match up to the physical flow. Additional acoustic treatment should be applied to the wind tunnel to further reduce sound pressure level since the noise level still exceeded the threshold of hearing loss.

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