Thermodynamics Quiz - Otto and Diesel Cycles

A region of matter separated from its surroundings by a real or imaginary boundary.

The substance within the system that undergoes changes, like air, water, or steam.

The real or imaginary line surrounding a system, allowing energy transfer in and out.

The area outside the system, directly interacting with the system.

The transfer of energy due to a temperature difference.

The process of expanding the working fluid in a gas power cycle without any heat transfer, resulting in a decrease in temperature and an increase in volume.

The ratio of the volume at the end of the isentropic expansion (v4) to the volume at the beginning of the isentropic expansion (v3).

The ratio of the volume at the end of the constant volume heat addition (v2) to the volume at the beginning of the constant volume heat addition (v1).

The process of rejecting heat from the working fluid at constant volume, resulting in a decrease in temperature.

The amount of heat rejected during the constant volume heat rejection process.

The ratio of the work output to the heat input in a thermodynamic cycle. It represents the efficiency of the cycle.

A gas power cycle that combines constant volume and constant pressure heat addition. It's often used in diesel engines.

The ratio of the volume at the end of the compression process (v2) to the volume at the beginning of the compression process (v1).

The ratio of the volume of the cylinder at the beginning of the compression stroke to the volume at the end of the compression stroke. It represents how much the air is compressed in the engine.

The ratio of the volume at the end of the heat addition process to the volume at the beginning of the heat addition process. It determines how much the volume is increased during the combustion process.

The heat added to the system during the constant pressure process. This is the heat released by the combustion of fuel.

The difference between the work done by the system and the work done on the system. It represents the net energy output of the engine.

A measure of the efficiency of the engine. It's calculated as the ratio of the net work output to the heat input.

Represents the amount of heat energy transferred to the system. It is usually the heat generated from burning fuel.

The amount of work done by the engine during the cycle. This is the work that can be used to power the vehicle.

A cycle where heat addition occurs at constant pressure, followed by an isentropic expansion, a constant-volume heat rejection process, and an isentropic compression.

The change in entropy for a reversible process is calculated by integrating the differential change in entropy (dS) over the process path, divided by the temperature (T).

The change in entropy for a constant volume process is calculated using the specific heat capacity at constant volume (Cv), the mass (m), and the temperature change (T2 - T1).

The entropy change for a constant volume process can be expressed in terms of the initial and final pressures (P1 and P2), the specific heat capacity at constant volume (Cv), and the mass (m).

The entropy change for a constant volume process (with pressure changes) is shown on a T-S (temperature-entropy) diagram.

The entropy change for a constant volume process can be either an increase or decrease in entropy, depending on whether the pressure increases or decreases.

The relationship between volume and entropy is illustrated with two different constant volume processes, one where pressure increases (a) and one where pressure decreases (b).

The entropy change for a constant volume process is illustrated on a T-S diagram, allowing us to visualize the relationship between temperature and entropy under different pressure changes.

A thermodynamic cycle that represents the maximum possible efficiency for any heat engine operating between two given temperatures.

The ratio of the work output from a heat engine to the heat input to the engine.

The process of expanding a working fluid in a turbine, converting its thermal energy into mechanical energy. The process is assumed to be adiabatic and reversible.

The process of transferring heat from the working fluid to a lower temperature reservoir, typically a condenser. The temperature remains constant during this process.

The process of compressing a working fluid in a pump, increasing its pressure. The process is assumed to be adiabatic and reversible.

The addition of heat to the working fluid, typically in a boiler. The temperature remains constant during this process.

The Carnot cycle is not practical because it is difficult to achieve isothermal heat transfer and isentropic processes in real-world systems.

The Carnot cycle requires compressing wet steam in a feed pump, which would require a large and powerful pump due to the high density of the fluid.

The ratio of net work output to the turbine work input in a steam power cycle.

The amount of work produced per unit of heat input in a Rankine cycle, describing the cycle's efficiency in converting heat to work.

The mass of steam needed to produce one kilowatt-hour of work in a steam power cycle.

The state after the feed pump where the pressure of the water increases significantly, while the temperature change is relatively small.

The state after the condenser, where the steam has been condensed into water, but the pressure remains relatively low.

The state after the boiler, where the steam is at its highest temperature and pressure in a Rankine cycle.

The state after the turbine, where the steam has expanded and done work, resulting in lower temperature and pressure.

The process of taking steam from the turbine and pumping it back to the boiler, using a pump to increase pressure.

The assumption that the work done by the feed pump is negligible compared to the work done by the turbine, simplifying the thermal efficiency calculation.

The process of converting high-pressure steam into water by reducing its temperature and pressure, typically using a condenser.