9.
a. Explain how auto exhaust, NOx and ozone (O3) are
related.
b. Explain the natural process for formation and
destruction of ozone in the stratosphere
c.Explain the human-caused destruction of ozone in the
stratosphere.
Explain some of the advantages and disadvantages of the single-
and dual- rate methods.
Explain advantages and disadvantages og the direct, the step-down
and the reciprocal methods.
According to the valve adjustment diagram in gasoline
engines, explain the following by stating on the figure. Intake
valve opening, before 15° (top dead spot), Intake valve closing
after 47° (bottom death spot), Exhaust valve opening before 41°
(bottom death spot), Exhaust valve closing after 10° (top dead
spot), Ignition advance before 15° (top dead spot)
According to the valve adjustment diagram in gasoline
engines, explain the following by stating on the figure. Intake
valve opening, before 15o (top dead spot), Intake valve closing
after 47o (bottom death spot), Exhaust valve opening before 41o
(bottom death spot), Exhaust valve closing after 10o (top dead
spot), Ignition advance before 15o (top dead spot)
Exhaust gases from a manufacturing plant are being discharged
through a 10-m-tall exhaust stack with outer diameter of 1.2 m. The
exhaust gases are discharged at a rate of 1.2 kg/s, while
temperature drop between inlet and exit of the exhaust stack is
30°C, and the constant pressure specific heat of the exhaust gasses
is 1600 J/kg·K. On a particular day, wind at 27°C is blowing across
the exhaust stack with a velocity of 10 m/s, while the outer
surface...
Exhaust gases having properties similar to dry air enter a
thin-walled square duct exhaust stack at 500 ºC. The stack is made
of galvanized iron and is 20 m tall and 0.25 m side. If the gas
flow rate is 0.5 kg/s and the stack surface has the outside ambient
temperature of 10 ºC estimate:
a) the outlet temperature of the exhaust gas
b) the heat transfer coefficient
c) the rate of heat transfer
d) the pressure drop