From 7f60ea012dd2524dae921a2a35adbf7ef21f2bb6 Mon Sep 17 00:00:00 2001 From: prashantsinalkar Date: Tue, 10 Oct 2017 12:27:19 +0530 Subject: initial commit / add all books --- 689/CH15/EX15.4/4.sce | 49 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) create mode 100644 689/CH15/EX15.4/4.sce (limited to '689/CH15/EX15.4/4.sce') diff --git a/689/CH15/EX15.4/4.sce b/689/CH15/EX15.4/4.sce new file mode 100644 index 000000000..5361d7386 --- /dev/null +++ b/689/CH15/EX15.4/4.sce @@ -0,0 +1,49 @@ +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"); -- cgit