Research On Drag Reduction Technology Of Aerated Vehicle With Strut

A new type of highly maneuverable surface vehicle or surface aircraft is now a hot topic in the research of high speed surface vehicles.Therefore,the application of supercavitation technology in high speed surface vehicles has been widely concerned.General supercavitation surface vehicle connects two torpedo-shaped underwater vehicles through the pillar structure,so that the surface of the submerged vehicle is covered by the whole cavity,so that the underwater vehicle does not directly contact with the water,reducing the resistance during navigation,so as to improve sailing speed.However,due to the existence of the prop,the supercavitation vehicle will cause great interference to the form of the supercavitation,and the surface of the submerged body cannot be completely covered by the supercavitation onlyIn this paper,a new drag reduction method combining ventilation cavitation and air layer is proposed for high-speed surface vehicle with pillar.Considering the complexity of the flow field around the pillar,the numerical simulation method is used to study it.The main research contents are as follows:Based on RANS equation,SST turbulence model and VOF multiphase flow model were used to study the influence of pillar on aerated cavitation flow.The numerical simulation of the experimental model with belly support in the water tunnel experiment was carried out,and the changes of cavity morphology under different ventilation rates were obtained,and the gas entrainment behind the branch was verified by the known experimental results.The influence of pillar shape on the cavitation flow field and the variation of the drag coefficient of the vehicle are analyzed.The ventilation supercavitation is combined with the drag reduction technology of the gas layer.By setting ventilation holes near the leading edge and trailing edge of the pillar to assist ventilation,the covering rate of the gas layer is increased and the drag reduction effect is improved.First of all,the influence of different shapes of struts on the surface of the submerged body bubble shape was compared,the best struts were selected to maintain the same ventilation rate,and the influence of different positions of the submerged body near the leading edge of the struts on the drag reduction effect and its influence principle were studied.The optimal position of ventilation holes at the leading edge of the pillar was selected.By setting ventilation holes at the front,middle and back of the trailing edge of the pillar respectively and maintaining the same ventilation rate,the influence of ventilation holes at different positions near the trailing edge of the pillar on drag reduction effect and its influence principle were studied.Using the best vent layout obtained from the above study,the drag reduction effect of this scheme is studied by changing the navigation depth.Using the optimal vent layout obtained from the above study,the influence of independent or coupled ventilation rate of leading edge vent and trailing edge vent on drag reduction effect was studied,and the ventilation rate required to achieve the optimal drag reduction rate was measured.At the same time,the influence of ventilation rate of leading edge vent hole and trailing edge vent hole on drag reduction effect after changing sailing speed was studied,and the change law of optimal drag reduction rate with sailing speed was obtainedIn this paper,a new drag reduction method combining ventilation superchamber and air layer is proposed through a large number of numerical simulation,and its optimal design shape is obtained,and the influencing factors of drag reduction effect are investigated,which can provide a meaningful reference for the design and implementation of related surface high speed vehicles...