Quiet@Remove["Global`*"];
$HistoryLength=2;
SetDirectory[NotebookDirectory[]];

mm=0.001;
Vsteckou=6*(10^(-3));
Dchar=30mm;
Pr=3.785;
λ=(10^(-3))Fit[{{40,628.6},{50,640.6}},{1,T},T]/.T->Tdef;
prurez=Pi*((Dchar^2)/4);
rychlost=(Vsteckou/prurez);
Print["v= ",rychlost,"m.(s^(-1))"];
Tdef=((330+310)/2)-273;
ν=5.83*(10^(-7));
Rey=((rychlost*Dchar)/ν);
Print["Re= ",Rey," -"]

Nu1=0.023*(Pr^0.4)*(Rey^0.8);
Print["Nu1= ",Nu1," -"]

Nu2=0.0296*(Pr^0.333)*(Rey^0.8);
Print["Nu2= ",Nu2," -"]

Nu3=0.015*(Pr^0.42)*(Rey^0.83);
Print["Nu3= ",Nu3," -"]

α=((Nu1*λ)/Dchar);
Print["α= ",α," W.(m^(-2)).(K^(-1))"]

Fit[{{40,628.6},{50,640.6},{60,650}},{1,T,(T^2)},T]

PrKyncl=0.707;
TdefKyncl=27.5+273.15;
λKyncl=26.47*(10^(-3));
νK=15.75*(10^(-6));
β=(1/TdefKyncl);
DcharKyncl=1.72;
ΔT=15;
Gr=((β*ΔT*(DcharKyncl^3)*9.81)/((νK)^2));
Nu1K=0.135*(((PrKyncl*Gr))^0.33);

αK=((Nu1K*λKyncl)/DcharKyncl)

(*nucena kolem Kyncla*)
ReyNuc=((10*0.3)/(νK));
NuNuc=0.226*(ReyNuc^0.6)*(PrKyncl^0.4);

αKNuc=((NuNuc*λKyncl)/0.3)

Solve[αKNuc*15==αK*(35-x),x]