Case 1:Constant Surface Heat Flux ·Example application Electrical heater element around a pipe Recognize that: qg≠f(x) From the energy balance equation 7(田=Tn+gPx ·ifq”is constant Entrance region Fully developed region T.() If g"is a known function of x instead,must T.(x) integrate the above to obtain Tm.x g=constant Heat Transfer #10 Su Yongkang School of Mechanical EngineeringHeat Transfer Su Yongkang School of Mechanical Engineering # 10 Case 1: Constant Surface Heat Flux • Example application – Electrical heater element around a pipe • Recognize that: • From the energy balance equation • if q ” is constant If q ” is a known function of x instead, must integrate the above to obtain Tm,x q f (x)  s   ( ) Tm,i x m c q P T x p s m    