The pressure fluctuation in the flow passage of both impeller and casing is addressed on design condition. The initial conditions for the unsteady turbulent simulation are resulted from the steady calculations, and th...The pressure fluctuation in the flow passage of both impeller and casing is addressed on design condition. The initial conditions for the unsteady turbulent simulation are resulted from the steady calculations, and the three dimensional unsteady turbulent simulation concerning the rotor-stator interaction is executed by a Navier-Stoke solver embedded with k -ε turbulence model and with appropriate moving interface boundary conditions. Detecting points are distributed in the flow passage in different radial and circumferential positions to capture the static pressure fluctuation character for one cycle of the impeller. The time-domain spectrums show that the static pressure curves are periodic and have five peaks and five valleys. With the radius increasing, the pressure fluctuation peak-to-peak values in the impeller are increasing, and reach the maximum value on the interface. In the casing flow passage, those values are about 7% of local static pressure except some ones near the tongue. The values become decreasingly in the diffuser pipe. The frequency spectrums transformed by fast Fourier transform （FFT） show that the dominant frequency is approximate with the blade passing frequency, and the pressure fluctuations in impeller passage have high frequency content while those in casing ones have no such information.展开更多
The paper refers to the analysis of interactions between the impeller and the vaned diffuser based on the air model of a radial flow pump.The study deals with a numerical simulation of the flow for a full 360°ent...The paper refers to the analysis of interactions between the impeller and the vaned diffuser based on the air model of a radial flow pump.The study deals with a numerical simulation of the flow for a full 360°entire impeller and diffuser.The task is carried out closely under the design operating conditions and for one particular position of the impeller blade with respect to the diffuser frame.Among all the results,the focus is mainly on the flow pattern at the exit part inside the impeller facing the diffuser vanes.The results are compared to the available PIV measurements.展开更多
基金supported by National Outstanding Young Scientists Funds of China (Grand No.50825902)
文摘The pressure fluctuation in the flow passage of both impeller and casing is addressed on design condition. The initial conditions for the unsteady turbulent simulation are resulted from the steady calculations, and the three dimensional unsteady turbulent simulation concerning the rotor-stator interaction is executed by a Navier-Stoke solver embedded with k -ε turbulence model and with appropriate moving interface boundary conditions. Detecting points are distributed in the flow passage in different radial and circumferential positions to capture the static pressure fluctuation character for one cycle of the impeller. The time-domain spectrums show that the static pressure curves are periodic and have five peaks and five valleys. With the radius increasing, the pressure fluctuation peak-to-peak values in the impeller are increasing, and reach the maximum value on the interface. In the casing flow passage, those values are about 7% of local static pressure except some ones near the tongue. The values become decreasingly in the diffuser pipe. The frequency spectrums transformed by fast Fourier transform （FFT） show that the dominant frequency is approximate with the blade passing frequency, and the pressure fluctuations in impeller passage have high frequency content while those in casing ones have no such information.
文摘The paper refers to the analysis of interactions between the impeller and the vaned diffuser based on the air model of a radial flow pump.The study deals with a numerical simulation of the flow for a full 360°entire impeller and diffuser.The task is carried out closely under the design operating conditions and for one particular position of the impeller blade with respect to the diffuser frame.Among all the results,the focus is mainly on the flow pattern at the exit part inside the impeller facing the diffuser vanes.The results are compared to the available PIV measurements.
