diff options
Diffstat (limited to '965/CH4/EX4.8')
-rw-r--r-- | 965/CH4/EX4.8/8.sci | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/965/CH4/EX4.8/8.sci b/965/CH4/EX4.8/8.sci new file mode 100644 index 000000000..569b25de9 --- /dev/null +++ b/965/CH4/EX4.8/8.sci @@ -0,0 +1,29 @@ +clc;
+clear all;
+disp("sphere exposed to airflow ")
+R=15/2000;//m radius of steel sphere
+ti=550;// degree C
+t=90;// degree C
+ta=20;// degree C
+k=42;// W/m.C
+h=120;// W/m^2.C
+a=0.045;//m^2/h
+Lc=R/3;//m
+rho=7850;// kg/m^3
+c=475;// J/kg.C
+As=4*3.1416*R^2;
+V=4*3.1416*(R^3)/3;
+Bi=h*Lc/k;
+disp(Bi,"Bi =")
+//Fo=a*tau/Lc^2;
+//(t-ta)/(ti-ta)=exp(Bi*Fo))
+X=-log((t-ta)/(ti-ta))
+Fo=X/Bi;
+disp(Fo,"Fo =")
+tau=Fo*Lc*Lc/(a/3600);
+disp("s",tau,"time required tau =")
+Fo=7200*0.0333;
+Qi=-h*As*(ti-ta)*(exp(-1*Bi*Fo));
+disp("W",Qi,"Instantaneous heat transfer rate 2 minutes after the start of cooling Qi =")
+Q = rho*V*c*(ti-ta)*((exp(-Bi*Fo))-1);
+disp("W",Q,"Total heat energy transfer from sphere during firsh 2 minutes Q =")
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