a boiler delivers 5400kg of steam per hour at a pressure of 750KN/m^2 and with a dryness fraction of 0.98.The feedwater of the boiler is at a temoerature of 41.5 °c . The coal used for firing the boiler haas a calorific value of 31000KJ/kg and is used at the rate of 670Kg/hr. Determine the thermal efficiency of the boiler and the equivalent evaporation F and A 100 °c .​

Afan that can provide air speeds up to 60 m/s is to be used in a low-speed wind tunnel with atmospheric air at 35 c. if one wishes to use the wind tunnel to study flat-plate boundary layer behavior up to reynolds numbes of re 10, what is the minimum plate length that should be used? at what distance from the leading edge would transition occur if the critical reynolds nurnber were rer,e = 5 × 105?