Home

controlevolume

Controlevolume, typically referred to as a control volume in English, is a defined region of space chosen for the application of conservation laws in fluid mechanics, heat and mass transfer, and related fields. The volume can be fixed in space (an Eulerian control volume), move with the fluid (a Lagrangian control volume), or take a hybrid form in computational methods such as the arbitrary Lagrangian-Eulerian (ALE) approach. The concept provides a practical frame for accounting for the accumulation of properties inside the volume and the fluxes across its boundary.

The key ideas are accumulation, flux through the control surface, and sources or sinks within the volume.

Applications of the control-volume approach are widespread. In engineering, it underpins the finite volume method in

The
rate
of
change
of
any
extensive
property
within
the
control
volume
is
related
to
the
net
flux
of
that
property
across
the
boundary
and
any
internal
generation
or
consumption.
This
relationship
is
formalized
by
the
Reynolds
transport
theorem,
which
links
the
time
rate
of
change
of
a
property
in
a
material
system
to
its
rate
of
change
within
a
control
volume
and
the
fluxes
across
the
boundary.
Common
properties
studied
include
mass,
momentum,
and
energy,
leading
to
the
continuity,
momentum,
and
energy
equations
used
in
analysis
and
simulation.
computational
fluid
dynamics
(CFD),
enabling
the
discretization
of
conservation
laws
for
complex
flows.
It
is
also
used
in
heat
and
mass
transfer
analysis,
environmental
engineering,
and
aerospace,
where
practical
boundaries
are
chosen
to
simplify
problem
geometry
and
enforce
physical
fluxes
across
surfaces.