CUVX Design Report - the AOE home page - Virginia Tech

CUVX Design – VT Team 2 Page 854.12 SeakeepingA seakeeping analysis in the full load condition was performed using the Ship Motion Program (SMP). Thehull was modeled using offsets from Fastship. Ship responses were calculated for a Bretschneider wave spectrum inSea States 3, 4, 5, 6, and 7 (significant wave heights of 0.88, 1.88, 3.25, 5, and 7.5 meters). Ship motions wereanalyzed at 8 locations. These locations are described in Table 50 below. The Post-Processing module of SMP wasused to create Speed-Polar plots showing the operating envelopes of the ship for Required Operational Capabilities(ROCs) using Navy criteria for operational limits. The plots show the regions in which the criteria are met as blank.The bold lines are the limit contour lines. The regions in which the ship did not pass the criteria are shown withcontour lines plotted in them. The numbers shown on each contour line are the value of the plotted criteria for theparticular Speed-polar plot. Significant amplitude criteria are listed in Table 51.DescriptionTable 50. Sea Keeping Analysis LocationsLongitudinal Vertical LocationLocation (mFP) (m basline)Bridge Center 16.5 20.1 0Outboard Corner of VLS Starboard 169.31 29.31 -10.61Outboard Corner of VLS Port 138.31 29.31 10.61Keel @ Sta. 3 33 0 0Bow/UCAV Launch 17.02 27.3 0UCAV Recovery 181 29.31 1Generic LAMP Aft Landing/Launch 168 29.31 -2Generic LAMP Forward Landing/Launch 123 29.31 -1Transverse Location(m CL port pos)MissionRoll(deg)Table 51. Limiting Sea Keeping Criteria for CUVXHI3 (Significant Amplitude)Pitch Yaw Vertical Lateral(deg) (deg)Acc (g) Acc (g)VertVel(m/s)LongAcc(g)WetnessperHour @BowSlamsperHour@Sta. 3SeaStateGoalThresholdSea StateSea StateAchievedAAW(VLS)17.5 3 1.5 0.6 0.7 0.3 7 6 6(limited)ASW(LAMPS)5 3 2.5 5 4 4(limited)ASuW(LAMPS)5 3 2.5 5 4 4(limited)ISR(UAV)5 3 2.5 5 4 4(limited)SEAD(UCAV)5 3 2.5 5 4 4(limited)UNREP 4 1.5 5 4 5 - 6(limited)Personnel 8 3 0.4 0.2 8 7 7(limited)Hull 30 20 8 7 7(limited)CUVX marginally satisfies seakeeping requirements. It provides only limited operations in the threshold seastates except for UNREP where it is fully operable.VLS (the primary AAW system) criteria are 17.5 degrees roll, 3 degrees pitch, and 1.5 degrees yaw.Longitudinal acceleration must be less than 0.3g, transverse acceleration less than 0.7g, and vertical acceleration lessthan 0.6g. The AAW operating envelope for Sea State 6 is shown in Figure 79. In CUVX, AAW operations are