a motor cycle cylinder consists of 10 fins ; each 15 cm outside diameter and inside diameter 7.5 cms. calculate rate of heat dissipation from cylinder fins when(i) motorcycle is stationary(ii) motorcycle is running at 60 km/hr.atmospheric air is at 20 degree celsius and avg fin temip is 480 celsius. the relevant thermo-physical properties at avg tem of 250 celsius aredensity = 0.674 kg/m^3 SPECIFIC HEAT = 1038 J/Kg Kthermal conductivity k = 0.427 prandtl no. Pr = 0.677kinematic viscosity v = 40.61 X 10^(-6) meter square/sB coefficient of cubical expanson = 1.912 X 10^(-3) per degree kelvinApprox value of heat transfer coefficient may be evaluated by idealing the fins as single horizontal flate plate of same area . use significant length l = 0.9 dNu = 0.54 ( Gr Pr)^ (0.25) for laminar flowNu = 0.036 (Re)^(0.8) X (Pr)^(0.33) for turbulent flowwhere Nu nussel no. Gr grashof no. Pr prandtl no. Re REYNOLDS NO.plz solve the problem urgently. i have exam tomorrow

Jitender Pal , 11 Years ago

Grade 9