Stress analysis and stress fatigue life prediction of RCP impeller based on fluid-thermal-solid coupling

•The paper focus on predicting the fatigue life of the impeller of the RCP rotor.•The unidirectional flow-thermal-solid coupling method is used to analyze the dynamic stress of the RCP impeller under multiple loads.•The fatigue form of the impeller is mainly stress fatigue, and the maximum equivalent stress value is 100.83 MPa, which appears at the junction of the suction surface (SS) of the blade and the front shroud.•Through nCode fatigue calculation, it is found that the shortest life of the impeller is at node 397, which can be cycled 2.833 × 1011 times, and the maximum damage is 3.53 × 10-12.