shows the diesel engine cycle. It is very similar to the Otto cycle (presented in the textbook), but with two important differences. First, the fuel is not added until the air is fully compressed at point 2. This is because at the end of adiabatic compression the fuel begins to burn spontaneously (there are no spark plugs in a diesel engine). Second, combustion occurs more slowly and with the fuel being injected continuously. This characterizes the ignition stage as a constant pressure process. The cycle shown in Fig.1 has an expansion Vmax - Vmın of 1000 cm^3 and compression ratio r = Vmax/Vmın = 21. These are typical values for a diesel-powered truck. The engine operates with air intake (γ = 1, 4) at 25°C and 1 atm. The amount of fuel injected into the cylinder has a heat of combustion of 1000 J. a. Find the value of p, V, and T, for each of the vertices of the cycle. Finally, arrange your result in a table format. b. What is the total work done by the cylinder in one complete cycle? c. What 'e the efficiency of the thermal machine? d. What is the power output in kW and horsepower (use 1 hp = 746 W) of an diesel engine running at 2400 rpm?
Fig.1 shows the diesel engine cycle. It is very similar to the Otto cycle (presented in the
textbook), but with two important differences. First, the fuel is not added until the air is fully compressed at point 2.
This is because at the end of adiabatic compression
the fuel begins to burn spontaneously (there are no spark plugs in a diesel engine).
Second, combustion occurs more slowly and with the fuel being injected continuously.
This characterizes the ignition stage as a constant pressure process. The cycle shown in
Fig.1 has an expansion Vmax - Vmın of 1000 cm^3
and compression ratio r = Vmax/Vmın = 21.
These are typical values for a diesel-powered truck. The engine operates with air intake
(γ = 1, 4) at 25°C and 1 atm. The amount of fuel injected into the cylinder has a heat of
combustion of 1000 J.
a. Find the value of p, V, and T, for each of the vertices of the cycle. Finally, arrange your
result in a table format.
b. What is the total work done by the cylinder in one complete cycle?
c. What 'e the efficiency of the thermal machine?
d. What is the power output in kW and horsepower (use 1 hp = 746 W) of an
diesel engine running at 2400 rpm?
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