  We calculate electronic charge and heat transport in tubular nanowires
generated by a temperature gradient or a chemical potential bias. These
nanowires correspond to semiconductor core-shell nanowires with insulating
(undoped) core and conductive (doped) shell, such that the conduction takes
place only in the shell. The cross section of such nanowires is typically
polygonal. We study the influence of the cross section shape and shell
thickness on the electric and heat conduction of the shell. We use the
Landauer-B\"uttiker approach to calculate the electric and heat currents as a
non-linear function of temperature and chemical potential bias beyond the
linear regime.
