Isothermal flow
Encyclopedia
Isothermal flow is a model of compressible fluid flow
whereby the flow remains at the same temperature while flowing in a conduit. In the model, heat transferred through the walls of the conduit is offset by frictional heating back into the flow. Although the flow temperature
remains constant, a change in stagation temperature occurs because of a change in velocity. The interesting part of this flow is that the flow is choked at
and not at Mach number
equal to one as in the case of many other model such as Fanno flow
.
For an important practical case of a gas
flow throw a long tube the model has an applicability in situations which occurs in a relatively long distance and where heat transfer is relatively rapid so that the temperature can be treated, for engineering purposes, as a constant. This model has also applicability as upper boundary to Fanno flow
.
Compressible flow
Compressible flow is the area of fluid mechanics that deals with fluids in which the fluid density varies significantly in response to a change in pressure. Compressibility effects are typically considered significant if the Mach number of the flow exceeds 0.3, or if the fluid undergoes very large...
whereby the flow remains at the same temperature while flowing in a conduit. In the model, heat transferred through the walls of the conduit is offset by frictional heating back into the flow. Although the flow temperature
Temperature
Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...
remains constant, a change in stagation temperature occurs because of a change in velocity. The interesting part of this flow is that the flow is choked at
and not at Mach numberMach number
Mach number is the speed of an object moving through air, or any other fluid substance, divided by the speed of sound as it is in that substance for its particular physical conditions, including those of temperature and pressure...
equal to one as in the case of many other model such as Fanno flow
Fanno flow
Fanno flow refers to adiabatic flow through a constant area duct where the effect of friction is considered. Compressibility effects often come into consideration, although the Fanno flow model certainly also applies to incompressible flow. For this model, the duct area remains constant, the flow...
.
For an important practical case of a gas
Gas
Gas is one of the three classical states of matter . Near absolute zero, a substance exists as a solid. As heat is added to this substance it melts into a liquid at its melting point , boils into a gas at its boiling point, and if heated high enough would enter a plasma state in which the electrons...
flow throw a long tube the model has an applicability in situations which occurs in a relatively long distance and where heat transfer is relatively rapid so that the temperature can be treated, for engineering purposes, as a constant. This model has also applicability as upper boundary to Fanno flow
Fanno flow
Fanno flow refers to adiabatic flow through a constant area duct where the effect of friction is considered. Compressibility effects often come into consideration, although the Fanno flow model certainly also applies to incompressible flow. For this model, the duct area remains constant, the flow...
.