Experimental study on the water entry of a vehicle with a single canard wing at an initial angle of attack

The use of flow control techniques is important to enhance vehicle motion stability during water entry. This paper introduces a method that applies a canard wing to the water entry problem, and the vertical water-entry process of a vehicle with a single canard wing at an initial angle of attack was experimentally studied. The cavity evolution and vehicle kinematics during water entry at various impact velocities and initial angles of attack were investigated. The results indicate that the fore-end cavity and the attached cavity on the wing are features of a vehicle with a canard wing during water entry. Unlike a wingless vehicle, the canard-wing configuration provides a restoring moment that corrects the deflection of the trajectory and attitude. As the impact velocity increased, the vehicle trajectory gradually corrected to a vertical straight-line trajectory before deflecting in the direction opposite to the side without a wing. As the initial angle of attack increased, the vehicle trajectory gradually shifted towards the side with the wing; however, the attitude remained stable without continuous deflection. The canard wing prevents a continuous change in attitude deflection caused by the initial angle of attack.