Office of Naval Research, 800 North Quincy Street, Arlington, VA 22217-5660

A -- EVALUATION AND TESTING OF NUMERICAL METHODS APPLICABLE TO THE SIMULATION OF UNDERWATER EXPLOSIONS AND THEIR EFFECTS ON NAVAL STRUCTURES. SOL N00014- POC Dr. Judah Goldwasser, ONR (703)696-2164. BAA 97-012. The Office of Naval Research is interested in evaluating and testing numerical methods applicable to the simulation of underwater explosions and their effects on naval structures. The requirements for the numerical schemes of interest are: I.) time accurate solutions to the Euler Equations in 1, 2 and 3 dimensions, ii. ) fully conservation and higher order accurate, iii.) applicable to fixed, rectangular grids, iv.) capable of treating an arbitrary number of multiple materials, such as gas and water, separated by a sharp interface, v.) applicable to bodies of arbitrary geometrical shapes with unsteady boundaries. Fulfilling requirements I. -- iv. are mandatory. Fulfilling requirement v. is highly desirable. The numerical method selected under this BAA will be implemented by technologists at the Naval Surface Warfare Center, with possible collaboration from the scheme developer, into an existing, fluid-structure code. This code will employ an Eulerian module to compute the fluid flow and a Lagrangian module to model the structure. The Eulerian and Lagrangian modules execute in tandem, passing information back and forth as the solution proceeds. A set of 19 test cases, outlined in a test document, has been constructed to evaluate the candidate numerical schemes. These cases span the range from 1-D model problems to 3-D explosion bubble simulations. This document describes each test case, defines the meshes on which it will be solved, prescribes the initial and boundary conditions, and specifies the deliverables. Typically, the results to be supplied included x-y and contour plots, prepared according to a specified format. The test document may be obtained directly from Dr. Judah Goldwasser, the cognizant ONR Program Officer (e-mail: goldwaju@onr.navy.mil). Participants in this study will apply the numerical scheme of their choice to this set of test cases and prepare the information, charts, and graphs stipulated by the test document. It is highly desirable to compute as many of the 19 test cases as possible. It is not mandatory to work all the test cases. Additionally, participants must provide the source code used to compute the test cases, user documentation, as well as all input files. Potential follow-on research on a next generation computational fluids scheme may develop under the ONR 6.1 Applied Analysis program in FY98. Proposals may be submitted in any format the offeror chooses, however, the following information must be included: 1) the basis for the algorithm(s), 2) description of the algorithm(s) & capabilities, 3) technical description of the numerical techniques to be employed, and 4) examples of previous problems the scheme/code has been used to address, including benchmark problems which demonstrate capability. Proposals under this announcement must be submitted by 15 MAR 1997. The following criteria, listed in descending order of importance will be used to evaluate proposals: (1) technical merits of the proposal and approach to fulfilling the requirements outlined in the test document, including choice of test cases to be computed, (2) potential contribution of the effort to achieving implementation of a fully functional, high fidelity weapons/weapons effects code capable of analyzing the performance of undersea weapons to a level of accuracy sufficient to support ONR and operational Navy missions, (3) the offeror's capabilities, related experience, facilities, techniques, or unique combinations of these that are integral factors for achieving the proposed objectives, (4) the qualifications, capabilities, and experience of proposed principal investigator, and key personnel who are critical in achieving the proposed objectives, and (5) realism of the proposed cost and availability of funds. This announcement constitutes a Broad Agency Announcement as contemplated by FAR 6.102 (d)(2). Readers should note that this is an announcement to declare ONR's intent to competitively fund research and that no request for proposals (RFP), solicitation or other announcement of this opportunitywill be made. Proposers should state in their proposal that it is submitted in response to this BAA. The standard industrial classification code is 8731 with the small business standard of 500 employees. At the end of this program, a downselection may be made based on proposals to integrate the findings of this project into the ONR Undersea Weaponry Program. Factors in the downselection include affordability, feasibility and availability of funds. (0044)

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