We consider the compressible isentropic Euler equations on
with a
pressure law
,
where
.
This includes all physically relevant cases, e.g., the monoatomic gas.
We investigate under what conditions on its regularity a weak solution
conserves the energy. Previous results have crucially assumed that
in the range of the density; however, for realistic pressure laws this means
that we must exclude the vacuum case. Here we improve these results by
giving a number of sufficient conditions for the conservation of energy, even
for solutions that may exhibit vacuum: firstly, by assuming the velocity to
be a divergence-measure field; secondly, imposing extra integrability on
near a vacuum;
thirdly, assuming
to be quasinearly subharmonic near a vacuum; and finally, by assuming that
and
are Hölder
continuous. We then extend these results to show global energy conservation for the
domain where
is bounded
with a
boundary. We show that we can extend these results to the compressible
Navier–Stokes equations, even with degenerate viscosity.
PDF Access Denied
We have not been able to recognize your IP address
18.207.160.97
as that of a subscriber to this journal.
Online access to the content of recent issues is by
subscription, or purchase of single articles.
Please contact your institution's librarian suggesting a subscription, for example by using our
journal-recommendation form.
Or, visit our
subscription page
for instructions on purchasing a subscription.