clc; funcprot(0); //Example 15.4 Thrust Horse Power for a fixed pitch propeller // Initialisation of variables V = 125*1.467; // Velocity in ft/sec n = 2200/60; // Rotaion per second D = 6; // Diameter in ft rho = 0.002378; // Calculations //For Beta = 23 degree VnD0 = V/(n*D); Ct0 = 0.075; Cp0 = 0.076; T0 = Ct0*rho*n^2*D^4; V = [VnD0 0.8 0.7 0.6 0.5 0.4 ]; Ct = [Ct0 0.082 0.100 0.120 0.132 0.144 ]; Cp = [Cp0 0.080 0.093 0.103 0.108 0.112 ]; CtByCp = diag(Ct)/diag(Cp); T = T0*(Cp0/Ct0)*CtByCp; Eff = diag(V)*diag(CtByCp); Eff0 = Eff(1); RPM = Eff/Eff0*2200; Cp0 = linspace(Cp0,Cp0, 6); Cp0ByCp = diag(diag(Cp0)/diag(Cp)) Eff/Eff0; Eff/Eff0*(n*60); bhp = [125 123 117 112 110 109]; // From manufactures chart thp = diag(bhp)*diag(Eff); sigma = 0.7384; // From table 4.1; Bhp10KBySL = 0.673; // Ratios of BHP from fig 14.3 RPMfactor = Bhp10KBySL/sigma; BHPfactor = RPMfactor*Bhp10KBySL; Result = zeros(6,9); Result(:,1) = V'; Result(:,2) = RPM; Result(:,3) = bhp'; Result(:,4) = diag(diag(Result(:,1))*diag(Result(:,2))*(D/88)); Result(:,5) = Eff; Result(:,6) = RPM*RPMfactor; Result(:,7) = bhp'*BHPfactor; Result(:,8) = Result(:,4)*RPMfactor; Result(:,9) = diag(diag(Result(:,7))*diag(Result(:,5))); //Results disp(Result,"!! V/nD rpm_SL bhp_SL V_SL Eff_SL rpm_10K bhp_10K V_10K thp_10K !!") ; disp("There is a calculation mistake in calculating n/no hence the dependent answer varies");