Housing
Light but strong materials, fully meeting thermal conductivity requirments,
are used for the housing structure itself.
New designs are also under developement, featuring the minimum amount
of material needed to cunduct the dissipated heat to the baseplate.
Thermal exchanges / cooling system
TWT´s offer an inherent advantage: dissipated power / radiated
energy can be generated at high temperatures, of 200°C for example
(this makes the heat sink funktion easier).
This means that, according to the Stefan-Boltzmann law, the surface
area required for radiation cooling can be reduced; a three-fold reduction,
for excample, if the radiating temperature is increased form 85°C
to 200°C.
Most of the sissipated power is generated in the collector. The collector
can hen operate at a higher temperature e.g. 200 C, than the TWT body,
and can therefore radiate heat directly towards deep space. Baced
on this fact, two design opproaches can be applied to reducethe weight
of the satellite`s thermal control system:
  direct
radiating collector
more
efficient heat path via the platform`s heat pipes.
|
TWT with cone radiator
 TWT
with fin radiator |
