From b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b Mon Sep 17 00:00:00 2001 From: priyanka Date: Wed, 24 Jun 2015 15:03:17 +0530 Subject: initial commit / add all books --- 2657/CH18/EX18.1/Ex18_1.sce | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) create mode 100755 2657/CH18/EX18.1/Ex18_1.sce (limited to '2657/CH18/EX18.1') diff --git a/2657/CH18/EX18.1/Ex18_1.sce b/2657/CH18/EX18.1/Ex18_1.sce new file mode 100755 index 000000000..f8f724e9f --- /dev/null +++ b/2657/CH18/EX18.1/Ex18_1.sce @@ -0,0 +1,34 @@ +//Calculations on petrol engine +clc,clear +//Given: +n=4 //Number of cylinders +d_o=7.5 //Diameter of orifice in cm +Cd=0.6 //Coefficient of discharge for orifice +d=11,l=13 //Bore and stroke in cm +N=2250 //Engine speed in rpm +bp=36 //Brake power in kW +m_f=10.5 //Fuel consumption in kg/hr +CV=42000 //Calorific value in kJ/kg +deltaP_o=4.1 //Pressure drop across orifice in cm of water +P=1.013 //Atmospheric pressure in bar +T=15+273 //Atmospheric temperature in K +g=9.81 //Accelaration due to gravity in m/s^2 +//Solution: +//(a) +eta_bt=bp*3600/(m_f*CV) //Brake thermal efficiency +//(b) +A=%pi/4*d^2*10^-4 //Area of cylinder in m^2 +bmep=bp*1000/(n*l/100*A*N/(2*60)) //Brake mean effective pressure in Pascal +//(c) +rho_w=1000 //Mass density of water in kg/m^3 +deltaP_o=rho_w*g*deltaP_o/100 //Pressure drop across orifice in N/m^2 +R=0.287 //Specific gas constant in kJ/kgK +rho_a=P*10^5/(R*10^3*T) //Mass density of air in kg/m^3 +A_o=%pi/4*d_o^2*10^-4 //Area of orifice in m^2 +m_a=Cd*A_o*sqrt(2*deltaP_o*rho_a) //Air inhaled in kg/s +V_s=(%pi/4)*d^2*l*n*N/(2*60)*10^-6 //Swept volume in m^3/s +eta_vol=m_a/V_s //Volumetric efficiency +//Results: +printf("\n (a)Brake thermal efficiency, eta_bt = %.3f",eta_bt) +printf("\n (b)Brake mean effective pressure, bmep = %.3f bar",bmep*10^-5) +printf("\n (c)Volumetric efficiency, eta_vol = %.3f\n\n",eta_vol) -- cgit