Search results
Results From The WOW.Com Content Network
The adiabatic (no heat exchanged) expansion of a gas may be carried out in a number of ways. The change in temperature experienced by the gas during expansion depends not only on the initial and final pressure, but also on the manner in which the expansion is carried out.
The adiabatic compression of a gas causes a rise in temperature of the gas. Adiabatic expansion against pressure, or a spring, causes a drop in temperature. In contrast, free expansion is an isothermal process for an ideal gas.
The exponent, , with which the expansion of the gas can be calculated by the application of heat is called the isentropic – or adiabatic coefficient. Its value is determined by the Rüchardt experiment. An adiabatic and reversible running state change is isentropic (entropy S remains the same as temperature T changes). The technique is ...
The Joule expansion (a subset of free expansion) is an irreversible process in thermodynamics in which a volume of gas is kept in one side of a thermally isolated container (via a small partition), with the other side of the container being evacuated. The partition between the two parts of the container is then opened, and the gas fills the ...
Equation of state; Ideal gas; Real gas; ... a corresponding isentropic device is called isentropic or adiabatic efficiency. ... be an isentropic expansion or ...
We assume the expansion occurs without exchange of heat (adiabatic expansion). Doing this work, air inside the cylinder will cool to below the target temperature. To return to the target temperature (still with a free piston), the air must be heated, but is no longer under constant volume, since the piston is free to move as the gas is reheated.
Under other conditions, free-energy change is not equal to work; for instance, for a reversible adiabatic expansion of an ideal gas, =. Importantly, for a heat engine, including the Carnot cycle , the free-energy change after a full cycle is zero, Δ cyc A = 0 {\displaystyle \Delta _{\text{cyc}}A=0} , while the engine produces nonzero work.
Here, work is entirely consumed by expansion against the surroundings. Of the total heat applied (709.3 kJ), the work performed (202.7 kJ) is about 28.6% of the supplied heat. Isobaric expansion of a gas pressurized to 2 atmospheres by a 10,333.2 kg mass. Like before, the gas doubles in volume and temperature while remaining at the same pressure.