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/EX18.13/Ex18_13.sce | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100755 2657/CH18/EX18.13/Ex18_13.sce

(limited to '2657/CH18/EX18.13')

diff --git a/2657/CH18/EX18.13/Ex18_13.sce b/2657/CH18/EX18.13/Ex18_13.sce
new file mode 100755
index 000000000..c742bf963
--- /dev/null
+++ b/2657/CH18/EX18.13/Ex18_13.sce
@@ -0,0 +1,35 @@
+//Calculations on four stroke engine
+clc,clear
+//Given:
+d=150,l=250 //Bore and stroke in mm
+Li=50 //Length of indicator diagram in mm
+Ai=450 //Area of indicator diagram in mm^2
+ISR=1.2 //Indicator spring rating in mm
+N=420 //Engine speed in rpm
+T=217 //Brake torque delivered in Nm
+m_f=2.95 //Fuel consumption in kg/hr
+CV=44000 //Calorific value in kJ/kg
+m_w=0.068 //Mass of cooling water used in kg/s
+deltaT_w=45 //Cooling water temperature rise in K
+cp=4.1868 //Specfic heat capacity of water in kJ/kgK
+//Solution:
+Hi_av=Ai/Li //Mean height of indicator diagram in mm
+imep=Hi_av/ISR //Mean effective pressure in bar
+ip=imep*100*%pi/4*d^2*l*N/(2*60)*10^-9 //Indicated power in kW (Error in book)
+bp=2*%pi*(N/60)*(T)*10^-3 //Brake power in kW
+eta_m=bp/ip //Mechanical efficiency (Error in book)
+eta_bt=bp*3600/(m_f*CV) //Brake thermal efficiency
+bsfc=m_f/bp //Brake specific fuel consumption in kg/kWh (Error in book)
+//Energy balance
+Power_f=m_f/3600*CV //Power in fuel in kW
+Power_w=m_w*cp*deltaT_w //Power to cooling water in kW
+Power_e=Power_f-bp-Power_w //Power to exhaust, radiation in kW
+//Results:
+printf("\n The mechanical efficiency, eta_m = %d percent",eta_m*100)
+printf("\n The brake thermal efficiency, eta_bt = %.1f percent",eta_bt*100)
+printf("\n The specific fuel consumption, bsfc = %.3f kg/kWh",bsfc)
+printf("\n\n   Energy balance\n\t Power in fuel = %.1f kW, %d percent",Power_f,Power_f/Power_f*100)
+printf("\n\t Brake power = %.2f kW, %.1f percent",bp,bp/Power_f*100)
+printf("\n\t Power to cooling water = %.1f kW, %.1f percent",Power_w,Power_w/Power_f*100)
+printf("\n\t Power to exhaust, radiation = %.1f kW, %.1f percent",Power_e,Power_e/Power_f*100)
+//Answers in the book are wrong
-- 
cgit