生物安全柜流动噪声的数值分析与降噪研究

发布时间：2018-04-15 14:50

本文选题：流动噪声 + 生物安全柜　；参考：《青岛理工大学》2014年硕士论文

【摘要】：生物安全柜是一种主要应用于微生物学、生物医学、动物实验等领域的科研、教学和临床试验的安全设备，也是实验室生物安全中的一级防护屏障。如今，生物安全柜的生产技术已发展成熟，性能要求也已达到较高的水平，然而在噪声方面的要求并没有相应的提高，仅仅停留在最初始的水平（低于67dB）。安全柜所产生的噪声是对操作人员最直观的影响，也决定着市场竞争力，，因而，在达到安全柜性能要求的基础之上，对其进行降低噪声是一个不可忽视的重要问题。本文对生物安全柜流动噪声进行研究，提出了降低噪声的措施。首先，对流动噪声与流场的关系及其产生机理进行了理论研究，利用气动声学理论分析了生物安全柜内部流场与噪声的关系，生物安全柜流动噪声源为偶极子声源，主要来源于流场中气流与气流及气流与固体表面之间的相互作用，建立了生物安全柜气流流场数学模型和噪声预测模型，然后在FLUENT软件基础上对生物安全柜的流场和噪声场进行了数值模拟计算，采用傅里叶快速变换求得流动声场的频谱图，对生物安全柜流动噪声的分布和影响因素进行了分析。论文分析了过滤膜的阻力特性对安全柜流动噪声的影响，针对不同阻力特性的过滤膜分别建立了流场噪声计算模型，对计算结果进行分析比较：在满足安全柜洁净性能要求的前提下，选择较小阻力的过滤膜可达到降低噪声的目的。此外，比较分析导流板的位置和形状得出：在导流板高度一定前提下，半圆弧度形状时产生噪声最小。对生物安全柜进行了流场和噪声测试，实验结果与模拟计算结果的变化趋势基本吻合，采取降低过滤膜阻力和优化导流板的措施对生物安全柜的降噪起到了很好的效果。本文提出的流动噪声理论分析方法对生物安全柜等相关设备的设计和降噪措施有一定的理论指导意义。
[Abstract]:Biosafety cabinets are mainly used in microbiology, biomedical, animal experiments and other fields of scientific research, teaching and clinical trials of safety equipment, but also in laboratory biosafety protection barrier.At present, the production technology of biosafety cabinet has been developed and the performance requirements have reached a higher level. However, the noise requirements have not been raised accordingly, and only stay at the initial level (below 67dBX).The noise generated by the safety cabinet is the most intuitive influence to the operator and also determines the market competitiveness. Therefore, it is an important problem to reduce the noise on the basis of meeting the performance requirements of the safety cabinet.In this paper, the flow noise of biosafety cabinets is studied, and the measures to reduce the noise are put forward.Firstly, the relationship between flow noise and flow field and its producing mechanism are studied theoretically. The relationship between flow field and noise in biosafety tank is analyzed by using aerodynamic acoustics theory. The flowing noise source of biosafety tank is dipole sound source.The mathematical model and noise prediction model of airflow field in biosafety tank are established mainly from the interaction between airflow and airflow and between airflow and solid surface in the flow field.Then the flow field and noise field of biosafety tank are numerically simulated on the basis of FLUENT software. The frequency spectrum of the flow sound field is obtained by Fourier fast transformation, and the distribution and influence factors of flow noise in biosafety tank are analyzed.The paper analyzes the influence of the resistance characteristics of the filter membrane on the flow noise of the safe tank, and establishes the flow field noise calculation model for the different resistance characteristics of the filter membrane.The calculation results are analyzed and compared: under the premise of satisfying the requirements of the clean performance of the safe cabinet, the noise can be reduced by choosing the filter membrane with lower resistance.In addition, by comparing and analyzing the position and shape of the guide plate, it is concluded that under the condition of certain height of the guide plate, the noise is minimized when the semi-circular radians are formed.The flow field and noise of the biosafety tank were tested. The experimental results were in good agreement with the simulated results. The measures of reducing the filter membrane resistance and optimizing the diversion plate had a good effect on the noise reduction of the biosafety tank.The theoretical analysis method of flow noise proposed in this paper has a certain theoretical significance for the design of biosafety cabinets and noise reduction measures.
【学位授予单位】：青岛理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：Q-337;TB53

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