cap Q dot equals the fraction with numerator cap delta cap T and denominator cap R sub t o t a l end-sub end-fraction Common Resistance Formulas Conduction (Plane Wall) Convection Cylindrical Conduction Critical Radius of Insulation
When checking a problem, verify if the given outer radius is less than, equal to, or greater than ( r_cr ). If ( r_2 < r_cr ), heat loss increases with more insulation. Most students incorrectly assume insulation always helps. cap Q dot equals the fraction with numerator
: Solutions treat heat flow like electric current, where temperature difference ( cap delta cap T ) is the voltage and heat transfer rate ( ) is the current. Conduction Resistance (Plane Wall) Convection Resistance Radiation Resistance Composite Walls cap Q dot equals the fraction with numerator