Accession Number : ADA319545

Title :   DDG-51 Flt-IIA Airwake Study. Part 2. Hangar Interior Flow.

Corporate Author : NAVAL RESEARCH LAB WASHINGTON DC CENTER FOR REACTIVE FLOW AND DYNAMICAL SYSTE MS

Personal Author(s) : Landsberg, Alexandra M. ; Sandberg, WilliamC. ; Young, Theodore R., Jr. ; Boris, Jay P.

PDF Url : ADA319545

Report Date : 15 NOV 1996

Pagination or Media Count : 20

Abstract : The FAST3D flow solver was used to determine the unsteady airwake and exhaust gas concentrations around the DDG-51 Flt-IIA superstructure and helicopter hangar areas. Previous simulations and analysis of the unsteady airwake show that the region over the helicopter landing deck has rapid, significant velocity fluctuations. A significant recirculated zone over the helicopter landing deck was seen which suggested the possibility of flow of stack gas into the helo hangars. Therefore, the flow field inside the hangars was investigated and compared against baseline results without the hangar doors open. The present results include analysis of 8 points inside the hangar areas and one point near the helicopter hover location. Analysis of the velocity fluctuations near the hover location showed that the fluctuations were in a range that would impact helicopter dynamics. Near and inside the hangars, the magnitude of the velocity was not significant; however, the gas concentrations in this region varied significantly due to the asymmetry of the superstructure. This report demonstrates that FAST3D can determine the asymmetric unsteady flow field based on a realistic representation of the ship superstructure, thus making it a useful tool for evaluating superstructure design options.

Descriptors :   *UNSTEADY FLOW, *GUIDED MISSILE SHIPS, *DESTROYERS, VELOCITY, POSITION(LOCATION), IMPACT, DYNAMICS, VARIATIONS, FLOW FIELDS, ASYMMETRY, BASE LINES, HELICOPTERS, AIRCRAFT LANDINGS, DOORS, HOVERING, HANGARS, GAS FLOW, FLUE GASES, SUPERSTRUCTURES.

Subject Categories : Marine Engineering
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE