A Study on Drag Reduction of Cylindrical Underwater Body Using Sintered Mesh

Jung, Chulmin; Paik, Bugeun; Kim, Kyungyoul; Jung, Youngrae

doi:2018.21.2.195

J. KIMS Technol > Volume 21(2); 2018 > Article

Research Paper

Journal of the Korea Institute of Military Science and Technology 2018;21(2):195-203.
DOI: https://doi.org/10.9766/KIMST.2018.21.2.195

A Study on Drag Reduction of Cylindrical Underwater Body Using Sintered Mesh

Chulmin Jung, Bugeun Paik, Kyungyoul Kim, Youngrae Jung

¹The 6th Research and Development Institute, Agency for Defense Development
²Korea Research Institute of Ships & Ocean Engineering, KIOST

소결 메쉬를 이용한 원통형 수중운동체 항력 감소 연구

정철민, 백부근, 김경열, 정영래

¹국방과학연구소 제6기술연구본부
²한국해양과학기술원 부설 선박해양플랜트연구소

Abstract

Among the techniques of reducing the drag to increase the speed of underwater moving bodies, we studied on the drag reduction method by gas injection. Researches on gas injection method have been paid much attention to reduce the drag of vessels or pipe inner walls. In this study, we used a sintered metal mesh that can uniformly distribute fine bubbles by gas injection method, and applied it to a cylindrical underwater moving body. Using the KRISO medium-sized cavitation tunnel, we measured both the bubble size on the surface of the sintered mesh and the bubble distribution in the boundary layer. Then, drag reduction tests were performed on the cylinder type underwater moving models with cylindrical or round type tail shape. Experiments were carried out based on the presence or absence of tail jet injection. In the experiments, we changed the gas injection amount using the sintered mesh gas injector, and changed flow rate accordingly. As a result of the test, we observed increased bubbles around the body and confirmed the drag reduction as air injection flow rate increased.

Key Words: Gas Layer Reduction, Bubble Drag Reduction, Sintered Mesh