Consider the air over a city to be a box 100 km wide, 100 km long and 1 km high. Clean air is blowing into the box along one of its sides with a speed of 4 m/s. A reactive air pollutant is emitted into the box at a rate of 10 kg/s and decays with a decay rate constant k = 0.20 h-1.

a)Find the steady-state concentration of the air pollutant if the air is assumed to be completely mixed.

b) If the wind speed suddenly drops to 1 m/s, and all other conditions remain the same, estimate the air pollutant concentration 2 hours later.

Asingle-geared blanking press has a stroke of 200 mm and a rated capacity of 320 kn. a cam driven ram is assumed to be capable of delivering the full press load at constant force during the last 15 percent of a constant-velocity stroke. the camshaft has an average speed of 90 rev/min and is geared to the flywheel shaft at a 6: 1 ratio. the total work done is to include an allowance of 16 percent for friction a) estimate the maximum energy fluctuation b) find the rim weight for an effective diameter of 1.2 m and a coefficient of speed fluctuation of 0.10

Give heat transfer applications for the following, (i) gas turbines (propulsion) ) gas turbines (power generation). (iii) steam turbines. (iv) combined heat and power (chp). (v) automotive engines

Compute the pressure drop of 30°c air flowing with a mean velocity of 8 m/s in a circular sheet-metal duct 300 mm in diameter and 15 m long. use a friction factor, f 0.02, and pair = 1.1644 kg/m a. 37.26 pa b. 25.27 pa n c. 29.34 pa d. 30.52 pa