Study of the head-capacity curves of an axial pump under high back-pressure conditions

Objective: to study the hydraulic characteristics of an axial pump under conditions where the external back pressure at the outlet exceeds the maximum pressure generated by the pump, and to determine the corresponding headcapacity curves (HCC) in this operating mode. Materials and methods. A hydraulic test bench was designed and assembled for the experiments, capable of generating outlet back pressure up to 200 mmHg. Measurements were performed using axial blood pump Stream Cardio (Russia). A series of tests was conducted at rotational speeds ranging from 7,500 to 10,000 rpm. Initial excess pressures of 85, 100, and 120 mmHg were applied. Results. The experimental data obtained on the hydraulic test bench made it possible to determine the complete HCC of the axial pump, including the reverse-flow region corresponding to negative flow rates. At a flow rate of 0 L/min, the pressure drop across the pump was 85 mmHg. At a pressure drop of 100 mmHg, the flow rate reached –2.5 L/min,