The turbocharger of an internal combustion engine consists of a turbine and a compressor. Hot exhaust gases flow through the turbine to produce work and the work output from the turbine is used as die work input to the compressor. The pressure of ambient air is increased as it flows through the compressor before it enters the engine cylinders. Thus, the purpose of a turbocharger is to increase the pressure of air so that more air gets into the cylinder. Consequently, more fuel can be burned and more power can be produced by the engine.
In a turbocharger, exhaust gases enter the turbine at 400°C and 120 kPa at a rate of 0.02 kg/s and leave at 350T. Air
enters the compressor at 50°C and 100 kPa and leaves at 130 kPa at a rate of 0.018 kg/s. The compressor increases the air pressure with a side effect: It also increases the air temperature, which increases the possibility of a gasoline engine to experience an engine knock. To avoid this, an aftercooler is placed after the compressor to cool the warm air by cold ambient air before it enters the engine cylinders. It is estimated that the aftercooler must decrease the air temperature below 80°C if knock is to be avoided. The cold ambient air enters the after-cooler at 30°C and leaves at 40°C. Disregarding any frictional losses in the turbine and the compressor and treating the exhaust gases as air, determine (a) the temperature of the air at the compressor outlet and (b) the minimum volume flow rate of ambient air required to avoid knock.
RESPIRATORY PHYSIOLOGY Example exam question: You’re driving your horse to a race, and there is a hole in the trailer near the exhaust pipe. By the time you get to the horse race, you open the door and what happens (There will be a wreck and the horse will bleed out, this will involve the cardiovascular system) o The horse falls out dead. The major function of the respiratory system is the exchange of gases. o Two major gases we exchange are carbon dioxide and oxygen. o We are dependent upon the concentration of the gases in the air we breathe (the atmosphere.) If the concentration changes, that disrupts the respiratory system. Going up really high, there’s not much oxygen. We ar