Hydrodynamic Model of Diver–DPV Coupled Multi-Body and Its Underwater Cruising Numerical Simulation

Hansheng Li,Jiawei Zhang,Haitao Zhu,Fenglei Han,Weipeng Zhang,Yuliang Wu

doi:10.3390/jmse9020140

Hansheng Li, Jiawei Zhang + Show 4 more

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https://doi.org/10.3390/jmse9020140

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Abstract

Diver propulsion vehicles (hereinafter referred to as DPV) are a kind of small vehicle with underwater high-speed used by divers, who are able to grasp or ride on, and operate the volume switch to change the speed. Different from unmanned underwater vehicles (UUVs), the interference caused by diver’s posture changing is a unique problem. In this paper, a Diver–DPV multi-body coupling hydrodynamic model considering rigid body dynamics and fluid disturbance is established by analyzing the existing DPV related equipment. The numerical simulation of multi-body articulated motion is realized by using Star-CCM+ overlapping grid and DFBI 6-DOF body motion method. Five cases of DPVs underwater cruising in a straight-line when restraining diver movement is simulated, and five cases with free diver movement are simulated too. Finally, the influence of the diver’s posture changing on the cruising speed resistance is analyzed, and the motion equation including the disturbance is solved. The final conclusion is that, the disturbance is favorable at high speed, which can reduce the cruising resistance, and unfavorable at low speed, which increases the cruising resistance. The friction resistance Ff always accounts for the main part in all speed cases.

Highlights

Diver propulsion vehicle is a kind of small vehicle with underwater high-speed used for divers [1], who are able to grasp or ride on, and operate the volume switch to change the speed
The results show that the total resistance of the diver–DPV coupled model in the water is Ff = Ff0 + Fdis, where Ff0 is the resistance value of restricting the direct navigation movement
By analyzing the existing DPV equipment, a set of diver–DPV multi-body coupling model considering rigid body dynamics and fluid disturbance is established in this paper

Summary

Introduction

Diver propulsion vehicle (hereinafter referred to as DPV) is a kind of small vehicle with underwater high-speed used for divers [1], who are able to grasp or ride on, and operate the volume switch to change the speed. The numerical simulation of DPV cruising in water is different from that of HOVs (human-occupied vehicles) and UUVs (unmanned underwater vehicles). In the traditional numerical simulation method, diver and DPV are regarded as a relatively fixed rigid body. While in the multi-body coupling model, the joints of diver body and DPV are regarded as a complex hinge connecting rod structure, which has active and driven motion, and the two have the influence of fluid disturbance and rigid hinge force. Using CFD (compulation fluid dynamics) method to simulate the underwater cruising of a multi-body coupling model, and predicting the performance and analyzing the posture of the diver are the keys to solving the design optimization problem of high-performance DPVs

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Discussion

Conclusion