3000 kg of water is heated per hour from 30 to 70 0C by pumping it through a certain heated section of a 25 mm diameter tube. If the surface of the heated section is maintained at 110 0C, estimate length of the heated section and the rate of heat transfer from the tube to water. The thermo-physical properties of water are: ρ = 971.6 kg/m3 ; μ = 0.355 x 10-3 kg/m-s; k = 0.667 W/m-deg; Cp = 4195 J/kg-deg. Use Nu = 0.023 (Re) 0.8 (pr) 0.4

Water at 55c flows across a flat plate whose surface temperature is held constant at 95c. if the temperature gradient at the plate's surface for a given value of x is 18 c/mm, find a) local heat transfer coefficient. b) heat flux

Ahot wire operates at a temperature of 200°c while the air temperature is 20°c. the hot wire element is a tungsten wire of 5 um diameter and 2 mm in length. plot using excel current, heat transfer and heat generated by the wire for air velocity varying from 1-10 m/s in steps of lm/s? matlab the sensor voltage output, resistance, or assume nu 0.989 re033pr13 take air properties at tr (200°c20°c)/2 = 110°c properties of tungsten: c 0.13 kj/kg.k 3 p 19250 kg/m k (thermal conductivity) = 174 w/m.k

Steam enters a converging nozzle at 3.0 mpa and 500°c with a at 1.8 mpa. for a nozzle exit area of 32 cm2, determine the exit velocity, mass flow rate, and exit mach number if the nozzle: negligible velocity, and it exits (a) is isentropic (b) has an efficiency of 94 percent