The jet flow deflection of aero-engine lubrication system was researched.The deflection mechanism was analyzed firstly.Then a three-dimensional numeric model of the nozzle was established based on the method and application of computational fluid dynamics(CFD).Then the spray direction with different inlet velocities and nozzle slenderness ratios was computed.Finally

the influential factor of the deflection and its rule were obtained through the comparison of the results.The study found that the radial velocity causeed the deflection of the spray direction.The greater ratios of radial velocity to normal velocity as well as length to diameter

the higher level the deflection.The results also show that the suitable match of inlet velocity and ratio of length to diameter result in no deflection.