A long cylindrical electrical heating element of diameter D=10mm, thermal conductivity k=240 W/mC, density =2700 kg/m^3 and specific heat c_p=900J/kgC is installed in a duct for which air flows in a cross flow over the heater at a temperature and velocity of 27C and 10m/s, respectively. Assume the heater surface temperature in a uniform, and neglect radiation. The heating element dissipates energy at a rate of 1000 W/m. Evaluate air thermal properties at 450K. Using the Hilpret correlation, determine the steady state wire surface temperature (C).