Numerical and experimental analysis of initial water impact of an air-dropped REMUS AUV
Roe, Stephen Michael
MetadataShow full item record
The initial water impact of a free-falling object is primarily related to the fluid forces on the wetted surface of the object. The shape-dependent added-mass coefficients express the fluid forces integrated over the body, and thus physically represent the additional inertia of water accelerated with fie body. The field of hydrodynamic impact has been primarily concerned with estimating the added-mass coefficients of various types of bodies for different water impact types, such as seaplane landings, torpedo drops, and ship slamming. In this study, a numerical model has been constructed to estimate the hydrodynamic impact loads of a REMUS dropped in free-fall from a helicopter in a low hover. Developed by von Alt and associates at Woods Hole Oceanographic Institution, the REMUS (Remote Environmental Monitoring Units) is a small, man-portable, torpedo shaped Autonomous Underwater Vehicle (AUV) that is normally operated from small boats for a variety of scientific, industrial, and military applications. Finite-element method software and computer aided drafting tools were used to create a simplified model of REMUS without fins, propeller, or transducers. This axisyrnmetric REMUS model was cut by a flat free surface at various pitch angles and submergence values, and a panel mesh of the wetted surface of the vehicle was created using an automatic mesh generator. Surface boundary conditions are enforced for the free surface by reflecting the body panels using the method of images. Each panel mesh was evaluated for its added-mass characteristics using a source collocation panel method developed by Dr. Yonghwan Kim, formerly of the Vortical Flow Research Laboratory (VFRL) at the Massachusetts Institute of Technology Experimental impact tests were conducted with a specially-instrumented test vehicle to verify the initial impact accelerations.
Submitted in partial fulfillment of the requirements of the degree of Master of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution February 2005
Showing items related by title, author, creator and subject.
Verification of a six-degree of freedom simulation model for the REMUS autonomous underwater vehicle Prestero, Timothy (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2001-09)Improving the performance of modular, low-cost autonomous underwater vehicles (AUVs) in such applications as long-range oceanographic survey, autonomous docking, and shallow-water mine countermeasures requires improving ...
Single Transponder Range Only Navigation Geometry (STRONG) applied to REMUS autonomous under water vehicles Hartsfield, J. Carl (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2005-08)A detailed study was conducted to prove the concept of an iterative approach to single transponder navigation for REMUS Autonomous Underwater Vehicles (AUVs). Although the concept of navigation with one acoustic beacon ...
Shroyer, Emily L.; Plueddemann, Albert J. (American Geophysical Union, 2012-03-20)Across-shelf transects over the eastern flank of Barrow Canyon were obtained in August 2005 with an autonomous underwater vehicle (AUV). Here, the shelf topography creates a “choke” point in which a substantial portion of ...