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The Brayton cycle, also known as the Joule cycle, is a thermodynamic cycle that describes the operation of certain heat engines that have air or some other gas as their working fluid. It is characterized by isentropic compression and expansion, and isobaric heat addition and rejection, though practical engines have adiabatic rather than ...
A PV diagram plots the change in pressure P with respect to volume V for some process or processes. Typically in thermodynamics, the set of processes forms a cycle, so that upon completion of the cycle there has been no net change in state of the system; i.e. the device returns to the starting pressure and volume.
Thermodynamic cycles may be used to model real devices and systems, typically by making a series of assumptions to reduce the problem to a more manageable form. [2] For example, as shown in the figure, devices such a gas turbine or jet engine can be modeled as a Brayton cycle. The actual device is made up of a series of stages, each of which is ...
The basic scheme of the IBC and temperature-enthalpy diagram are presented in figures 1 and 2. [4] For external heat sources or high temperature storage systems, the closed process design of the inverted Brayton Cycle is also possible. The overall efficiency can thus be significantly increased. [5]
The PV diagram is a particularly useful visualization of a quasi-static process, because the area under the curve of a process is the amount of work done by the system during that process. Thus work is considered to be a process variable , as its exact value depends on the particular path taken between the start and end points of the process.
Net indicated mean effective pressure (IMEP) is calculated using the indicated power; i.e., the pressure volume integral in the work per cycle equation. Sometimes the term FMEP (friction mean effective pressure) is used as an indicator of the mean effective pressure lost to friction (or friction torque) and is just the difference between IMEP ...
Isotherms of an ideal gas for different temperatures. The curved lines are rectangular hyperbolae of the form y = a/x. They represent the relationship between pressure (on the vertical axis) and volume (on the horizontal axis) for an ideal gas at different temperatures: lines that are farther away from the origin (that is, lines that are nearer to the top right-hand corner of the diagram ...
Some specific values of n correspond to particular cases: = for an isobaric process, = + for an isochoric process. In addition, when the ideal gas law applies: = for an isothermal process,