A Slow Descent Deep-sea Lander with Integrated Hydrodynamic Plate^*

Most passive deep-sea landers rely on free fall under their own gravity. However, a major challenge is the uncontrollable landing speed, which can cause damage to the onboard instruments and disrupt the in-situ environment of the landing site's boundary layer if the landing speed is too fast. This paper presents a new research scheme for precise deceleration landing of deep-sea lander. The device's stability and low-speed landing are guaranteed by controlling the hydraulic plate's expansion area through the attitude self-adjusting system. CFD hydrodynamic numerical analysis is used to study the resistance during the landing process. The hydraulic plate structure is simple, easy to operate, and requires low energy consumption, making it suitable for long-term continuous in-situ monitoring of the deep sea.