Study on stall characteristics of the water jet propulsion pump device based on entropy generation theory and third-generation vortex identification method

The generation of stall conditions will directly affect the hydraulic and energy characteristics of the water jet propulsion pump. Utilizing the entropy generation theory, this study conducts a comparative analysis of the entropy generation loss distribution across each water jet propulsion pump device component under varying flow conditions. The investigation delineates the entropy generation loss variation with changes in the flow rate, revealing that the impeller and the inlet duct emerge as the primary contributors to entropy generation loss in the system. Through a comparative analysis of the flow patterns and entropy generation loss rate distribution under design conditions and two stall conditions for the inlet duct and impeller section, this study elucidates the entropy generation loss distribution characteristics in these sections. The investigation aims to provide insights into the factors contributing to the occurrence of high entropy generation areas. Additionally, the Liutex Omega vortex identification method is employed in this study to elucidate the correlation between vortex structure and the entropy generation loss rate distribution under diverse operating conditions. This approach further substantiates the underlying reasons for the observed entropy generation loss rate distribution.