Isothermal flow

العربية

Edit links

From Wikipedia, the free encyclopedia

Model of fluid flow

Thermodynamics

The classical Carnot heat engine

Branches

Equilibrium / Non-equilibrium

Laws

Systems

State
Equation of state Ideal gas Real gas State of matter Phase (matter) Equilibrium Control volume Instruments
Processes
Isobaric Isochoric Isothermal Adiabatic Isentropic Isenthalpic Quasistatic Polytropic Free expansion Reversibility Irreversibility Endoreversibility
Cycles
Heat engines Heat pumps Thermal efficiency

System properties

Note: Conjugate variables in italics

Process functions
Property diagrams Intensive and extensive properties
Work Heat
Functions of state
Temperature / Entropy (introduction) Pressure / Volume Chemical potential / Particle number Vapor quality Reduced properties

Material properties

Property databases

Specific heat capacity

c=

{\displaystyle c=}

T

{\displaystyle T}

\partial S

{\displaystyle \partial S}

N

{\displaystyle N}

\partial T

{\displaystyle \partial T}

Compressibility

\beta =-

{\displaystyle \beta =-}

1

{\displaystyle 1}

\partial V

{\displaystyle \partial V}

V

{\displaystyle V}

\partial p

{\displaystyle \partial p}

Thermal expansion

\alpha =

{\displaystyle \alpha =}

1

{\displaystyle 1}

\partial V

{\displaystyle \partial V}

V

{\displaystyle V}

\partial T

{\displaystyle \partial T}

Equations

Potentials

Internal energy
$U(S,V)$ {\displaystyle U(S,V)}
Enthalpy
$H(S,p)=U+pV$ {\displaystyle H(S,p)=U+pV}
Helmholtz free energy
$A(T,V)=U-TS$ {\displaystyle A(T,V)=U-TS}
Gibbs free energy
$G(T,p)=H-TS$ {\displaystyle G(T,p)=H-TS}

History
Culture

History
General Entropy Gas laws "Perpetual motion" machines
Philosophy
Entropy and time Entropy and life Brownian ratchet Maxwell's demon Heat death paradox Loschmidt's paradox Synergetics
Theories
Caloric theory Vis viva ("living force") Mechanical equivalent of heat Motive power
Key publications
An Inquiry Concerning the Source ... Friction On the Equilibrium of Heterogeneous Substances Reflections on the Motive Power of Fire
Timelines
Thermodynamics Heat engines
Art Education
Maxwell's thermodynamic surface Entropy as energy dispersal

Scientists

Other

Category

icon

This article needs attention from an expert in Physics. The specific problem is: See Talk page, section "???". WikiProject Physics may be able to help recruit an expert. (August 2012)

This article includes a list of general references, but it lacks sufficient corresponding inline citations . Please help to improve this article by introducing more precise citations. (April 2021) (Learn how and when to remove this message)

Isothermal flow is a model of compressible fluid flow whereby the flow remains at the same temperature while flowing in a conduit.^[1] 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 stagnation temperature occurs because of a change in velocity. The interesting part of this flow is that the flow is choked at $1/{\sqrt {k}}$ {\displaystyle 1/{\sqrt {k}}} and not at Mach number equal to one as in the case of many other model such as Fanno flow. This fact applies to real gases as well as ideal gases.

For the important practical case of a gas flow through a long tube, the model has applicability in situations where distance is relatively long and heat transfer is relatively rapid so temperature can be treated, for engineering purposes, as a constant. This model also has applicability as upper boundary to Fanno flow.