The Design And Analysis Of Fluid Dynamic Characteristics For Submersible Unmanned Aerial Vehicle

The submersible unmanned aerial vehicle is a new type of aircraft that can both sail in the water and fly in the air.It can realize the rapid deployment and high-speed flight in the air as well as the concealment of underwater navigation which makes it capable of multi-tasking and efficient striking.Compared with the common unmanned aerial vehicles,there are more technical difficulties in structural layout,power energy and medium transition mode for the design of submersible unmanned aerial vehicle.However,the developments of aeronautical design,manufacturing and assembly technology have pushed forward the design process for submersible unmanned aerial vehicle,and more and more research institutions are beginning to conduct research on key technologies.A new type of submersible unmanned aerial vehicle combing the bionic fins and duct fan is designed under the support of the natural science foundation of Jiangsu Province in this paper.This submersible unmanned aerial vehicle realizes underwater movement using the bionic fins and flight in the air using the duct fan system which makes it mobility of flight in the air and the concealment of underwater navigation.With the principle of designing aircraft,the overall design was completed,and then the aerodynamics for the flight in the air and hydrodynamics for the underwater movement were analyzed in this paper afterwards,the prototype of the submersible unmanned vehicle was built and related experiments were conducted afterwards which verified the rationality of the design.First of all,the overall design of the submersible unmanned aerial vehicle was carried out.Through the analysis of the design characteristics of the bionic stingray robot,as well as the design method of the submersible unmanned aerial vehicle,the overall design scheme was decided by combining the bionic annular pectoral fin and the ducted fan system.The overall design of the aircraft,including the selection and performance accounting of the overall parameters of the ducted propeller system as well as the underwater pectoral fin propulsion system,was carried out based on the determination of the overall technical requirements.Secondly,the aerodynamic characteristics of the flight in the air and the hydrodynamic characteristics of the underwater navigation were analyzed.The maneuverability of the submersible unmanned vehicle is greatly influenced by its fluid dynamic characteristics,so it is very important to study its fluid dynamic characteristics.The aerodynamic analysis uses the momentum source method to numerically study the flight performance of the isolated propeller,the ducted propeller and the integrated ducted propeller system;the hydrodynamic analysis is mainly for the dynamic characteristics of the bionic annular pectoral fin propulsion.the overall propulsive force was calculated by using the UDF program and the motion under the pectoral fin propulsion of the submersible unmanned aerial vehicle was simulated through the dynamic mesh technology.The flow field information such as the pressure distribution on the fin surface and the vorticity generated by the fluctuating fins were analyzed afterwards.The performance of the two thrusters was analyzed and the rationality of the design was verified by analyzing the dynamic characteristics of the aircraft moving in two medias.Finally,the prototype of the submersible unmanned aerial vehicle was developed and a series of experiments were conducted afterwards.According to the overall parameters and the selected structural parameters of the main components,the detailed design,including the design of the ducted fan system and the bionic pectoral fin wave system,was conducted for the submersible unmanned aerial vehicle.The experiments for underwater motion under the bionic pectoral fin propulsion were carried out on the prototype machine,and the swimming performances such as the pectoral fin propulsion and the moving speed under the propulsive force were analyzed.Meanwhile,the thrust test of propeller and the tethering tests for hovering in the air were carried out for the duct-fan system,which verifies the performance of the ducted propeller system.In addition,experiments for working on the water-surface provides practical basis for the follow-up researches.