title: [Numerical simulation of the internal noise in the pressure generator of a continuous positive airway pressure ventilator].
abstract: It is important to overcome the problem of noise for the research and development of ventilator technologies. Previous research of this subject showed that the pressure generator, produced by German EMB-PAPST Company and specially used for continuous positive airway pressure (CPAP) ventilator, created noise easily, due to local backflow in the volute, uneven velocity distribution in the impeller and local negative pressure in the inlet of the impeller. Based on the previous research, a combination of the computational fluid dynamics (CFD) software FLUENT and steady-state solution of noise source of Reynolds-Averaged Navier-Stokes (RANS) was used in this study. We combined equation of Lilley and Synthetic Turbulence to get the information about speed fluctuation of the pressure generator, which is used to finish noise prediction. After detailed analysis, it showed that noise source of different degrees spreaded around the inlet of the impeller and the volute, interface of blade edge and corner of the volute tongue, which influenced its overall performance to certain extent. Therefore, its structural design needs to be improved.
authors.affiliation: School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China. y_z_cheng@yahoo.com.cn
authors.forename: Yunzhang
authors.initials: Y
authors.lastname: Cheng
authors.forename: Fangfang
authors.initials: F
authors.lastname: Huang
authors.forename: Lihua
authors.initials: L
authors.lastname: Zhu
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D045422:Continuous Positive Airway Pressure / Q000009:adverse effects / Q000295:instrumentation*; D004867:Equipment Design / Q000379:methods; D008962:Models, Theoretical; D009622:Noise / Q000517:prevention & control*