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Diffstat (limited to '1328/CH2/EX2.3')
| -rw-r--r-- | 1328/CH2/EX2.3/2_3.sce | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/1328/CH2/EX2.3/2_3.sce b/1328/CH2/EX2.3/2_3.sce new file mode 100644 index 000000000..c05db8979 --- /dev/null +++ b/1328/CH2/EX2.3/2_3.sce @@ -0,0 +1,16 @@ +printf("\t example 2.3 \n");
+printf("\t approximate values are mentioned in the book \n");
+Lair=0.25/12; // thickness of air film,ft
+Kair=0.0265; // thermal conductivity of air at 572F,Btu/(hr)*(ft^2)(F/ft)
+A=1; // surface area,ft^2
+Rair=Lair/(Kair*(A)); // resistance offered by air film, (hr)(F)/Btu
+printf("\t resistance offered by air film %.2f (hr)(F)/Btu \n",Rair);
+R=4.45; // resistance from previous example 2.2,(hr)(F)/Btu
+Rt=(R)+Rair; // total resistance,(hr)(F)/Btu
+printf("\t total resistance %.2f (hr)(F)/Btu \n",Rt);
+Ta=1600; // temperature of inner wall,F
+Tb=125; // temperature of outer wall,F
+Q=(1600-125)/Rt; // heat loss, Btu/hr
+printf("\t heat loss %.2f Btu/hr \n",Q);
+printf("\t It is seen that in a wall 18 in. thick a stagnant air gap only .25 in. thick reduces the heat loss by 15 percent \n");
+//end
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