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Diffstat (limited to '3765/CH1/EX1.5/Ex1_5.sce')
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diff --git a/3765/CH1/EX1.5/Ex1_5.sce b/3765/CH1/EX1.5/Ex1_5.sce new file mode 100644 index 000000000..e6906bcad --- /dev/null +++ b/3765/CH1/EX1.5/Ex1_5.sce @@ -0,0 +1,32 @@ +clc +// Example 1.5.py +// Consider the air in the pressure vessel in Example 1.2. Let us now heat +// the gas in the vessel. Enough heat is added to increase the temperature +// to 600 K. Calculate the change in entropy of the air inside the vessel. + +// Variable declaration from example 1.2 +V = 10 // volume of vessel (m^3) +p = 20.0 // pressure (atm) +T = 300.0 // initial temperature (K) +T2 = 600.0 // final temperature (Kelvin) +R = 287.0 // gas constant (J/Kg/K) +gamma1 = 1.4 // ratio of specific heats for air + + +// Calculations +p2_by_p = T2/T // p2/p, at constant volume p/T = constant + +cv = R / (gamma1-1) // specific heat capacity at constant volume (J/Kg K) +cp = cv + R // specific heat capacity at constant pressure (J/Kg K) + +p = p * 101000.0 // units conversion to N/m^2 +rho = p/R/T // from ideal gas equation of state (Kg/m^3) +m = V * rho // total mass = volume * density (Kg) + +// +del_s = cp*log(T2/T) - R*log(p2_by_p) // change in entropy per unit mass (J/ Kg K) +total_del_s = m*del_s // total change in entropy (J/K) + +// Result +printf("\n Total change in entropy is %.3e J/K", total_del_s) + |