Study of constant-head pump at starting period with LES model

To get more accurate flow in the constant-head pump at starting period, a test model was created. The LES model was used to simulate the inner flow at the starting period. The external characters and their time derivatives were obtained. The blade loading on the middle streamline were analyzed. Normalized helicity was used to analyze vortexes in impeller and vortex core was extracted by the normalized helicity. The results show that vortex core regions grow and merge along the streamwise as rotational speed increases. The tendency of constant-head pump´s external characters such as flow rate, head and power is similar to rotational speed. These characters change violently for the beginning of startup because of the fast increase of rotational speed. The blade shape can influence the blade loading.