Study on Bubble Collecting Section of Cavitation Tunnel for Ventilated Supercavitation Experiments

The gas ventilated by supercavitation splits into smaller bubbles and follows the water passage of the cavitation tunnel. The bubbles quickly return to the test section by rather high speed flow, and interrupt the observation of the supercavitation. To secure clear observation in the test section, the bubble collecting section(settling chamber) of large volume is prepared to collect bubbles in the water passage ahead of the test section. The bubble collecting section should provide enough buoyancy effect to the bubbles for proper bubble collecting. However, rather high-speed oncoming flow produces non-uniform velocity distribution and deteriorates buoyancy effect in the bubble collecting section. In the present study, the bubble collecting space and three porous plates are designed and analyzed through numerical methods, and the bubble collecting function is experimentally validated by 1/10-scaled model in terms of the formation of uniformly low velocity distribution in the bubble collecting section.

환기 초공동 실험을 위한 캐비테이션 터널 기포 포집부 연구