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Diffstat (limited to '2510/CH11/EX11.12/Ex11_12.sce')
| -rwxr-xr-x | 2510/CH11/EX11.12/Ex11_12.sce | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/2510/CH11/EX11.12/Ex11_12.sce b/2510/CH11/EX11.12/Ex11_12.sce new file mode 100755 index 000000000..d808e5af5 --- /dev/null +++ b/2510/CH11/EX11.12/Ex11_12.sce @@ -0,0 +1,35 @@ +//Variable declaration: +D = 0.0833 //Diameter of tube (ft) +L = 2.0 //Length of tube (ft) +h = 2.8 //Heat transfer coefficient (Btu/h.ft^2.°F) +Ta1 = 1500.0+460.0 //Temperature of hot air in furnace (°R) +Ta2 = 1350.0+460.0 //Temperature of hot air in the furnace brick walls (°R) +Tt = 600.0+460.0 //Surface temperature of tube (°R) +E = 0.6 //Surface emissivity of tube +s = 0.1713*10**-8 //Stefan-Boltzmann constant +pi = %pi + +//Calculation: +//Case 1: +A = pi*D*L //Area of tube (ft^2) +Qc = round(h*A*(Ta1-Tt)*10**-1)/10**-1 //Convection heat transfer from air to tube (Btu/h) +Qr = round(E*s*A*(Ta2**4-Tt**4)*10**-2)/10**-2 //Radiation feat transfer from wall to tube (Btu/h) +Q = Qr+Qc //Total heat transfer (Btu/h) +//Case 2: +Qp = Qr/Q*100 //Radiation percent +//Case 3: +hr = Qr/(A*(Ta2-Tt)) //Radiation heat transfer coefficient (Btu/h.ft^2.°F) +//Case 4: +T = Ta2-Tt //Temperature difference (°F) + +//Result: +printf("1. The convective heat transferred to the metal tube is : %f Btu/h.",Qc) +printf(" The radiative heat transferred to the metal tube is : %f Btu/h.",Qr) +printf(" The total heat transferred to the metal tube is : %f Btu/h .",Q) +printf("2. The percent of total heat transferred by radiation is : %.1f %%.",Qp) +printf("3. The radiation heat transfer coefficient is : %.1f Btu/h.ft^2.°F.",hr) +if (T > 200) then + printf("4. The use of the approximation Equation (11.30), hr = 4EsTav^3, is not appropriate.") +elseif (T < 200) then + printf("4. The use of the approximation Equation (11.30), hr = 4EsTav^3, is appropriate.") +end |