Research On Low Noise Structure And Numnerical Simulation Of Inner Flow For Roots Blower

Roots blowers are applied widely in the department of gas transportation of various industries due to its merits, such as simple, stable and without internal compression. However, it is an outstanding issue that the blowers generate noise and vibration, not only for increasing wear and reducing the service life of equipment, but also for environment pollution and affecting health of human body, thus, the scope of application of blowers is limited and the market competitiveness is reduced. Consequently, based on the project of the Natural Science Foundation of Shandong Province "Research on Roots Blower Noise Source Identification and Prediction Models (Y2006F38)", the low noise structure performance and the parameters of inner flow are studied for the theory foundation of the structural optimization design on blowers. The main contents and contributions in the dissertation are as follows:The structure and thermodynamic properties of Roots blower are analyzed, the quantitative relationship between theoretic flow, internal leakage flow, external leakage flow, actual flow, volumetric efficiency with airflow pulsation is established and the relationship between each parameter is studied.The low noise structural parameters and gas load of Roots blower are researched, the noise source is analyzed, the main measures of noise control are studied, and the low-noise design principle of blower is present.The contour line of Roots blower involute three-lobe impeller is created by AutoCAD; and in order to be a reasonable design, the solid model of Roots blower main components is established and assembled virtually by SolidWorks. Finally, the blower internal working condition is simulated by SolidWorks, for the purpose of making out the internal structure and operation principle.Two-dimensional model and mathematical model of inner flow numerical simulation for blower are established, the dynamic grids are come true by Profile, the advantages of three-lobe countercurrent cooling Roots blower of reducing airflow pulsation and aerodynamic noise are indicated after numerical simulation on different type and different condition by FLUENT, on this basis, the low-noise optimal design strategy is proposed.