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Diffstat (limited to '3685/CH20/EX20.11/Ex20_11.sce')
-rw-r--r-- | 3685/CH20/EX20.11/Ex20_11.sce | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/3685/CH20/EX20.11/Ex20_11.sce b/3685/CH20/EX20.11/Ex20_11.sce new file mode 100644 index 000000000..5d7e3552e --- /dev/null +++ b/3685/CH20/EX20.11/Ex20_11.sce @@ -0,0 +1,38 @@ +clc
+// Given that
+Bp = 40 // Brake power when all cylinder operating in kW
+N = 2000 // Speed in rpm
+Bp1 = 32.2 // Brake power with cylinder no. 1 cut out in kW
+Bp2 = 32 // Brake power with cylinder no. 2 cut out in kW
+Bp3 = 32.5 // Brake power with cylinder no. 3 cut out in kW
+Bp4 = 32.4 // Brake power with cylinder no. 4 cut out in kW
+Bp5 = 32.1 // Brake power with cylinder no. 5 cut out in kW
+Bp6 = 32.3 // Brake power with cylinder no. 6 cut out in kW
+d = 100 // Diameter of cylinder in mm
+L = 125 // Stroke of cylinder in mm
+Vc = 0.000123 // Clearance volume in m^3
+m_f = 9 // Fuel consumption in kg/h
+cv = 40 // Heating value in MJ/kg
+printf("\n Example 20.11\n")
+Ip1 = Bp-Bp1
+Ip2 = Bp-Bp2
+Ip3 = Bp-Bp3
+Ip4 = Bp-Bp4
+Ip5 = Bp-Bp5
+Ip6 = Bp-Bp6
+Ip = Ip1+Ip2+Ip3+Ip4+Ip5+Ip6
+n_m = Bp/Ip
+bmep = Bp*2*60/(L*(10^-3)*((d*(10^-3))^2)*(%pi/4)*N)
+Vs = (%pi/4)*((d*(10^-3))^2)*(L*(10^-3))
+r_k = (Vs+Vc)/Vc
+n_ase = 1- (1/(r_k^(1.4-1)))
+n_th = Ip*3600/(m_f*cv*1000)
+R_e = n_th/n_ase
+printf("\n Mechanical efficiency = %d percent,\n Brake mean effective pressure = %f bar\n Air standard ratio = %f percent,\n Brake thermal efficiency is %f percent,\n Relative efficiency = %f percent",n_m*100,bmep*(10^-2),n_ase*100,n_th*100,R_e*100)
+//The value of answer for air standard efficiency is different because of round off error
+// Answer given in the book for bmep is 3.055 bar which is wrong.
+// Answer given in the book for brake thermal efficiency is 40 percent which is wrong.
+// Answer given in the book for relative efficiency is 68.6 percent which is wrong.
+
+
+
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