# awk script 
#
# the begin command is executed BEFORE anything else is done
BEGIN {FS=" ";
"date" | getline date;
print date
}
#
{N=N+1}
{if(N==1) {printf "Input file [ %12s ]\n",FILENAME ;
print "#----------------------Input---------------------#"}}
{if($1=="Rinner") {rinner=$2;print$0}}
{if($1=="Length") {lgth=$2;print$0}}
{if($1=="Flow") {flow=$2;print$0}}
{if($1=="Cp") {cp=$2;print$0}}
{if($1=="Internal") {Tint=$2;Hint=$3;print$0}}
{if($1=="Layer1") {thick1=$2;kond1=$3;print$0}}
{if($1=="Layer2") {thick2=$2;kond2=$3;print$0}}
{if($1=="Layer3") {thick3=$2;kond3=$3;print$0}}
{if($1=="Layer4") {thick4=$2;kond4=$3;print$0}}
{if($1=="Ambient") {Tamb=$2;Hamb=$3;print$0}}
#
END {
# input dimension are mm's 
{r1=rinner}
{r2=r1+thick1}
{r3=r2+thick2}
{r4=r3+thick3}
{r5=r4+thick4}
# 
{term1=1/Hint}
{term2=(r1/1000./kond1)*log(r2/r1)}
{term3=(r1/1000./kond2)*log(r3/r2)}
{term4=(r1/1000./kond3)*log(r4/r3)}
{term5=(r1/1000./kond4)*log(r5/r4)}
{term6=r1/r5/Hamb}
#
{U=1/(term1+term2+term3+term4+term5+term6)}
#
# next assumes that Tamb does not change
# also Tint is now the entrance temperature of the internal fluid
{QoverL=U*6.283*(rinner/1000.)*(Tint-Tamb)}
{area=6.283*(rinner/1000.)*(lgth/1000.)}
{Texit=Tamb-(Tamb-Tint)*(2.71828^(-U*area/flow/cp/1000.))}
# next are the layer temperatures, starting on inner side
# assumes thicknesses are in mm's
#
# At the inlet station:
{T1=Tint-QoverL*(1/6.283/(r1/1000.)/Hint)}
{T2=T1-QoverL*log(r2/r1)/(6.283*kond1)}
{T3=T2-QoverL*log(r3/r2)/(6.283*kond2)}
{T4=T3-QoverL*log(r4/r3)/(6.283*kond3)}
{T5=T4-QoverL*log(r5/r4)/(6.283*kond4)}
{T5check=Tamb+QoverL*(1/6.283/(r5/1000.)/Hamb)}
#
# At the exit station:
{QoverLexit=U*6.283*(rinner/1000.)*(Texit-Tamb)}
{T1exit=Texit-QoverLexit*(1/6.283/(r1/1000.)/Hint)}
{T2exit=T1exit-QoverLexit*log(r2/r1)/(6.283*kond1)}
{T3exit=T2exit-QoverLexit*log(r3/r2)/(6.283*kond2)}
{T4exit=T3exit-QoverLexit*log(r4/r3)/(6.283*kond3)}
{T5exit=T4exit-QoverLexit*log(r5/r4)/(6.283*kond4)}
{T5checkexit=Tamb+QoverLexit*(1/6.283/(r5/1000.)/Hamb)}
#
{print "#----------------------Output--------------------#"}
{printf("%-12s %12.1f\n","Overall HTC", U)}
{printf("%-12s %12.1f\n","Q/L at inlet",QoverL)}
{printf("%-12s %12.1f\n","T(fluid exit)",Texit)}
{printf("%-12s %12.1f\n","Q/L at exit",QoverLexit)}
{print " "}
{print "                   Inlet          Exit "}
{printf("%-12s %12.1f %12.1f\n","T1",T1,T1exit)}
{printf("%-12s %12.1f %12.1f\n","T2",T2,T2exit)}
{printf("%-12s %12.1f %12.1f\n","T3",T3,T3exit)}
{printf("%-12s %12.1f %12.1f\n","T4",T4,T4exit)}
{printf("%-12s %12.1f %12.1f\n","T5",T5,T5exit)}
{printf("%-12s %12.1f %12.1f\n","T5check",T5check,T5checkexit)}
#
{print " "}
{print "#.......................End of File..............#"}
}