For twin nozzle short take off and vertical landing (STOVL) aircraft lift loss

Reynolds-averaged turbulence k-ε model was employed to simulate the aerodynamic flow field of STOVL aircraft and its lift loss. The effects of suck down and additional lift of STOVL aircraft on lift loss were studied

and curves of suck down during steady and dynamic processes were acquired. Results showed that suck down mainly depended on low pressure area generated by entrained flow

and additional lift had little effects on lift loss. When dimensionless height was lower than 3.5

suck down was larger than 10% of the aircraft lift. Dynamic and steady processes were compared

and suck down in the dynamic process was greater than that in the steady status

especially at dimensionless height 2

nearly 20.6% difference. The movement and development delay of main vortex was the cause of this difference of suck down during steady and dynamic processes.