Prediction Of Opening Type Axial-Impeller Using A Surface Panel Method

The mixing results of agitator depend directly on dynamic performance of the agitator paddle and the position in mixing tank. As the axial-flow stirrer are widely used in industry, people think much to their performance and agitating effect, but the research is not enough. Because of difficulties in measuring three-dimensional turbulent flow field in agitator, and theory of the paddle design is not inaccurate, predictions of the flow characteristics and mixing result of agitator are not accurate. To improve the basic theory of propeller and agitator, the surface panel method is applied to numerical computation in this thesis.This paper studied the performance of axial-impeller and axial-flow stirrer with panel method and agitator experiment, and compared with the calculations of CFX-TASCflow. Firstly, the author attempted to improve the surface panel method program which is used widely in prediction of propeller performance on grid generation, influence coefficients, wake model and so on, at the same time subroutine calculated induced velocity was added to main program. By using the amended program, the right characteristics and induced velocity results was computed. And then application of the panel method to predict the performance and induced velocity of axial-flow stirrer was studied. After that CFX-TASCflow was used to calculate the characteristics of axial impeller for comparison. Furthermore, the author designed and installed an experimental equipment of axial-flow stirrer, the impeller is Zm60 axial-pump impeller. The flat-bottomed agitating tank's is made of diaphanous organic glass. This experiment measured the stirrer's torques in different rev and recorded the inner flow field lively. At last, the calculated results used panel method was compared with results of experiment and the CFX-TASCflow, in performance, induced velocity and pressure distribution on blades.The comparison mentioned above indicates that numerical results of surface panel method for both axial-impeller and axial-flow stirrer is consistent with theCFX-TASCflow and experiment results. The improved program can get better performance prediction and induced velocity of impeller, and the pressure distribution also accorded with reality. Using this program can get satisfactory result, which is relatively close to the experiment. The value and its change trend of the induced velocity are coincident with those of theoretical research and experimental observation comparatively. So the panel method theory and program are suitable for axial-flow stirrer's performance prediction and induced velocity calculation.This paper is an opening project of university's laboratory of the JiangSu province, namely STUDY ON THE FLOW CHARACTERISTIC AND THE MIXED EFFECTS OF THE AXIAL FLOW IMPELLER, and supported by the research project plan of STUDY ON VERTICAL AXIAL PUMP AND INSTALLATION of the national great technical equipment.