不同结构主扇扩散器局部阻力研究

在大主扇通风系统中多采用低压大流量风机，在风机出风段多安装扩散器，主要作用是降低出口动压提高风机静压而达到回收出风口断面动能的效果。重点分析风流在流经不同结构扩散器时的流场以及出口的动能损失，叙述了紊流过程中产生阻力的原因，实验测定风流在扩散器后的静压和出口断面的速度。通过数值模拟和实验证明:流线型扩散器局部阻力较小，且具有较高的动能回收率和扩散器效率。结果表明此内容研究对研究扩散器的最优设计参数和通风节能具有一定的指导作用。

Research on local ventilation resistance in main fan diffuser with different structure

The fan with low pressure and large flow has usually been applied in the large fan ventilation system, and the diffuser has usually been installed in the outlet section of fan so as to recover the sectional kinetic energy at the outlet by reducing the kinetic pressure at the outlet and increasing the static pressure of fan. The flow field and loss of kinetic energy at the outlet when the airflow passing though the diffuser with different structure were analyzed with emphasis. The reasons for resistance producing in the process of turbulence flow were complained, and the static pressure after the diffuser and the velocity at the outlet section of airflow were measured by experiments. The results of numerical simulation and experiments showed that the streamlined diffuser has lower local resistance, higher recovery rate of kinetic energy and diffuser efficiency. It has certain guideline effect for studying the optimal design parameters of diffuser to achieve good ventilation performance and reduce power consumption.