One-dimensional inverse problem design method for guide-vane-free staggered contra-rotating turbine

The invention provides a one-dimensional inverse problem design method for a guide-vane-free staggered contra-rotating turbine. The one-dimensional inverse problem design method comprises the steps that (1) a method for calculating the inlet and outlet circumferential speed of a kth-stage moving vane based on the design radius in a turbine inlet vane, the high-pressure and low-pressure shaft rotating speed, the turbine total rim power, the power distribution coefficients of the first-stage turbine to the kth-stage turbine and the stage loading coefficients of the first-stage turbine to the kth-stage turbine is established; 2) establishing a method for calculating the axial speed of the inlet and the outlet of the kth-stage moving blade based on the absolute speed of a turbine inlet, the airflow angle of the turbine inlet, the circumferential speeds of the inlet and the outlet of the first-stage to the kth-stage moving blade and the flow coefficients of the first-stage to the kth-stage moving blade; and 3) est