An experimental study was performed to investigate the deflection of film trajectory on a flat blade model under the rotating operating conditions.The moving trajectory of film was mainly governed by the inertial force and radial pressure gradient in the blade passage.A new dimensionless parameter Φ

which is related to the ratio of the above two forces to determine the radial deflective angle of the film trajectory

was demonstrated in the present study.The steady-state thermochromic liquid crystal(TLC) technique was employed for flow visualization

and all the signals from the rotating reference frame were collected and transmitted to the stationary receiver via a wireless launcher

which was fixed in the rotation laboratory bench.The experimental results demonstrate that the spanwise deflection of film trajectory decrease with the increase of Φ values.