2results about How to "High drag reduction rate" patented technology

The present application relates to a kind of multi-stage combined jet intelligent collaborative control systems, including being set on the bottom plate of ship slit multi-stage combined jet drag reduction device, multi-stage jet device includes first stage slit jet device, second stage hole jet device and third stage hole jet device sequentially arranged from right to left;Including multi-stage combined jet optimization module and command module;Multi-stage combined jet optimization module is used to the jet flow required for the individualized adjustment of first stage slit jet device, second stage hole jet device and third stage hole jet device, jet area and jet angle parameter are predicted, and the best multi-stage combined jet form of current ship navigation state is obtained;Command module is used to control multi-stage combined jet device according to the predicted parameters respectively to jet area, jet flow is adjusted in the direction, and jet scheme is continuously iterated.The present application improves the gas utilization rate of ship bottom to a certain extent, and reduces the power consumption of jet system.

This invention discloses a method for preparing a superhydrophobic drag-reducing coating and its application in a manta ray-inspired submersible prototype, belonging to the technical field of underwater drag reduction and surface functional materials. The method includes: dispersing micron-sized SiO2 and nano-sized SiO2 in ethyl acetate to obtain a first dispersion; dispersing PDMS in ethyl acetate to obtain a second dispersion; mixing and stirring the first and second dispersions, then adding a curing agent and long-chain perfluoroalkyl silane PFDTES, followed by spraying and curing to obtain a PFDTES-PDMS@SiO2 coating. This invention achieves a water contact angle >150° and a roll-off angle <9° through the synergistic effect of PFDTES long-chain fluorination modification, PDMS flexible bonding, and the micro / nano dual-scale SiO2 hierarchical structure. In the manta ray-inspired submersible application, a drag reduction rate of 14.43% is achieved at a flow rate of 0.5 m / s, and the performance remains stable after 24 hours of dynamic water flow impact. This invention features a simple process, controllable cost, and is suitable for drag reduction functionalization of complex curved underwater equipment.