Program of resistance prediction planing and pre-planing ships Project : Designer : Filename : MyPowerBoat.fbm Design length : 8.000 m Design beam : 2.500 m Design draft : 0.380 m Midship location : 4.000 m Water density : 1.025 t/m^3 Appendage coefficient : 1.0000 Date : 11-11-2014 Time : 22:15:35 ---------------------------------------------------------------------------------- Input variables Hull Effective waterline length : 7.430 m Beam on waterline : 1.918 m Draft hull : 0.380 m Wetted surface area : 12.17 m^2 Prismatic coefficient : 0.7018 Displacement : 1.94 t Deadrise amidships : 0.000 degr X of CoG : 3.187 m Midship area above waterline : 0.00 m^2 Roughness coefficient *10^3 : 0.400 Maximal speed : 20.00 knots Midship area : 0.360 m^2 Transom area : 0.150 m^2 Half entrance angle of DWL : 21.060 degr ---------------------------------------------------------------------------- FrV is outside valid domain 1,0 ... 2,0 Final calculations of resistance and power by Mercier and Savitsky's method +-------+-------+-------+---------+---------+---------+---------+ | Vs | FrB | FrV | R_f | R_r | R_t | Pe | | [kn] | - | - | [kN] | [kN] | [kN] | [kW] | +-------+-------+-------+---------+---------+---------+---------+ | 7.20 | 0.85 | 1.06 | 0.203 | 0.755 | 0.958 | 3.55 | | 7.62 | 0.90 | 1.13 | 0.225 | 0.903 | 1.128 | 4.42 | | 8.04 | 0.95 | 1.19 | 0.249 | 1.025 | 1.274 | 5.27 | | 8.47 | 1.00 | 1.25 | 0.274 | 1.115 | 1.388 | 6.05 | | 8.89 | 1.05 | 1.31 | 0.299 | 1.181 | 1.480 | 6.77 | | 9.31 | 1.10 | 1.38 | 0.326 | 1.238 | 1.564 | 7.49 | | 9.74 | 1.15 | 1.44 | 0.354 | 1.303 | 1.657 | 8.30 | | 10.16 | 1.21 | 1.50 | 0.383 | 1.368 | 1.751 | 9.15 | | 10.58 | 1.26 | 1.56 | 0.413 | 1.403 | 1.816 | 9.88 | | 11.01 | 1.31 | 1.63 | 0.444 | 1.426 | 1.869 | 10.58 | | 11.43 | 1.36 | 1.69 | 0.475 | 1.445 | 1.921 | 11.29 | | 11.85 | 1.41 | 1.75 | 0.508 | 1.460 | 1.968 | 12.00 | | 12.28 | 1.46 | 1.81 | 0.542 | 1.470 | 2.013 | 12.71 | | 12.70 | 1.51 | 1.88 | 0.577 | 1.495 | 2.073 | 13.54 | | 13.12 | 1.56 | 1.94 | 0.614 | 1.628 | 2.242 | 15.13 | | 13.55 | 1.61 | 2.00 | 0.651 | 1.904 | 2.555 | 17.80 | +-------+-------+-------+---------+---------+---------+---------+ Calculated FrV= 2.953 +----------------------------------------------+ | Parameter | Calculated | Optimal | +-----------------+--------------+-------------+ | L/B | 3.874 | 5.379 | | Cg=D/(Rho*g*B^3)| 0.269 | 0.517 | | Beta | 0.000° | 15.446° | | Xg=LCG/L | 0.429 | 0.411 | +----------------------------------------------+ C.W.F.Hamilton & Co. type of waterjet calculation, according to [1,2]: Vs = 13.55 kn = 6.968 m/s = 25.09 km/hour Nwj = 1 Ct = 2.900 Cp = 5.964 EtaW = 0.486 Power (P) = 36.61 kW = 49.74 BHP Impeller Type: 9 11 12 13 14 15 RPS (n) = 26.5 25.5 24.4 23.5 23.1 22.7 RPM (n) = 1587 1532 1463 1410 1386 1359 Nwj = 2 Ct = 1.450 Cp = 2.687 EtaW = 0.540 Power (P) = 16.49 kW = 22.41 BHP Impeller Type: 9 11 12 13 14 15 RPS (n) = 20.3 19.6 18.7 18.0 17.7 17.4 RPM (n) = 1217 1174 1122 1081 1063 1042 Power*Nwj = 32.98 kW = 44.82 BHP Nwj = 3 Ct = 0.967 Cp = 1.754 EtaW = 0.551 Power (P) = 10.77 kW = 14.63 BHP Impeller Type: 9 11 12 13 14 15 RPS (n) = 17.6 17.0 16.2 15.6 15.4 15.1 RPM (n) = 1056 1019 973 938 922 904 Power*Nwj = 32.30 kW = 43.89 BHP Nwj = 4 Ct = 0.725 Cp = 1.322 EtaW = 0.548 Power (P) = 8.11 kW = 11.02 BHP Impeller Type: 9 11 12 13 14 15 RPS (n) = 16.0 15.4 14.8 14.2 14.0 13.7 RPM (n) = 961 927 886 853 839 823 Power*Nwj = 32.46 kW = 44.10 BHP REFERENCES: 1. Donald M. MacPherson.- A Universal Parametric Model for Waterjet Performance, HydroComp, Inc., Presented at FAST-99, Aug 1999. 2. HydroComp, Inc., "Waterjet Data Files for NavCad", HCI Report No. 119, December 1997. Copyright (c) 2008-2012, Timoshenko V.F.