<p>This study investigates the effects of mass flow and swirl of the secondary air on the aerodynamic performance of a linear turbine cascade with tip clearance subject to the secondary air injection from the upstream casing. Experimental tests and numerical simulations are conducted to examine the deviation and loss; and to analyze relevant flow dynamics. With an increasing mass flow ratio (MFR) of the secondary air to the main flow, the loss associated with passage vortex (PV) associated loss is increased due to the increased shear between the spanwise flow and streamwise flow near the suction side of the blade in the upper half span. Simultaneously, tip loading is reduced, decreasing the tip clearance vortex (TCV) loss. With increasing swirl ratio (SR) of the secondary air to the main flow, the slot exit vortices (which form due to the difference in the tangential velocities of the main flow and the secondary air) merge with the PV and increase the PV loss. Finally, MFR has a stronger effect on deviation and total loss than SR.</p>