Problems on Dual– Cycle Analysis, Performance and Comparison

What is the main difference between the Otto cycle and the Diesel cycle?

• Fuel type

• Color of the engines

• Number of cylinders

• Ignition method

Calculate the thermal efficiency of an engine operating on the Otto cycle given the compression ratio.

• thermal efficiency = 1 - (1 / compression ratio)

• thermal efficiency = 1 - (1 / compression ratio^(γ-1))

• thermal efficiency = 1 - (compression ratio^(γ-1))

• thermal efficiency = 1 - (1 / γ)

Explain the concept of specific fuel consumption in relation to engine performance.

• Specific fuel consumption is the measure of fuel efficiency in terms of engine weight.

• Specific fuel consumption is the ratio of fuel used to the engine's maximum speed.

• Specific fuel consumption is the amount of fuel consumed per unit of distance traveled by the engine.

• Specific fuel consumption is the amount of fuel consumed per unit of power produced by the engine, usually expressed in units like kg/kWh or g/hp-hr.

Compare the performance of an engine operating on the Otto cycle versus the Diesel cycle.

• The Otto cycle is used in gasoline engines with spark ignition, while the Diesel cycle is used in diesel engines with compression ignition.

• The Otto cycle is used in diesel engines with compression ignition, while the Diesel cycle is used in gasoline engines with spark ignition.

• The Diesel cycle is used in gasoline engines with spark ignition, while the Otto cycle is used in diesel engines with compression ignition.

• The Otto cycle is more fuel-efficient than the Diesel cycle.

How does the thermal efficiency of an engine change with an increase in compression ratio in the Diesel cycle?

• The thermal efficiency of an engine increases with an increase in compression ratio in the Diesel cycle.

• The thermal efficiency of an engine decreases with an increase in compression ratio in the Diesel cycle.

• The thermal efficiency of an engine is not affected by the compression ratio in the Diesel cycle.

• The thermal efficiency of an engine remains constant with an increase in compression ratio in the Diesel cycle.