Help with Thermodynamics: Engine Coolant Flow Rate & Air Volume

[hogeboon1]

1)
Engine coolant (glycol-water mixture) enters the radiator of a car at a temperature of 100C and exits it at 50C. If
the coolant must remove 30 kW of heat, what must be its mass
flow rate through the radiator? If the heat is carried off
by ambient air at about one atmosphere that has a temperature of 15 degrees before
flowing through the radiator and 35
degrees after it, what is the volume
flow of the air? [You can take the properties of the engine coolant to be the same as
liquid water at the same temperature]

Not sure how to do this problem, professor just lectures with no real structure. Could use some help on how to do this. Thanks

 

[Valkarie]

! Mass Flow Rate of Coolant: The heat removed by the coolant, Q, can be calculated using the equation Q = mCp(T2-T1). Since we know the heat removed (30 kW), the mass flow rate, m, can be calculated as: m = Q/(Cp(T2-T1)) = 30kW/(4.18 kJ/kgK * (50 - 100)) = 3.34 kg/s. Volume Flow Rate of Air: The volume flow rate of the air can be calculated using the equation Q = mCp(T2-T1). Since we know the heat removed (30 kW) and the mass flow rate of the air (1 kg/s), the volume flow rate, V, can be calculated as: V = Q/(Cp(T2-T1)) = 30kW/(1.005 kJ/kgK * (35 - 15)) = 27.03 m3/s.