Study on the flow characteristics of tandem supercavitating vehicles near the free surface

DOI:	10.11809/bqzbgcxb2023.08.028
Keywords:	free surface; supercavitation; tandem vehicles; numerical simulation
Abstract:	The multiphase flow characteristics of tandem supercavitating vehicles near the free surface are very complex. They not only involve the coupling effect of the free surface and the cavitation, but also the mutual interference of two or more supercavitating flow fields. This paper uses the VOF method to simulate the multiphase flow of tandem vehicles under different immersion depths. It also obtains the supercavitation evolution characteristics and flow field distribution characteristics of the tandem vehicles, and analyzes the effects of the free surface on supercavity shape and wave characteristic height. The results show that the supercavitation of the tandem bi vehicles appears the phenomena of fusion and separation of the two supercavities and collapse of the tail bubbles during the development process. The interaction of the supercavitation flow field causes the second vehicle to enter the interior supercavity of the first vehicle, which reduces the drag of the second vehicle. The tandem arrangement of the vehicles enables the second vehicle to achieve the drag reduction effect. When the immersion depth is shallow, the effect of the free surface is obvious, the supercavity shape of the vehicle has poor upper and lower symmetry, the characteristic height of the wave rising from the free surface is large, and the pressure distribution in the high pressure area at the front end is asymmetric along the center line of the vehicles.
Issue:	Vol. 44 No. 8 (2023)
Published:	2023-08-28
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