Enclosure_3,_Thermal_Model.pdf

ENCLOSURE 3

SIMPLIFIED MODEL OF THE THERMAL

ENVIRONMENT AROUND THE COLD

SENSING MODULE

RFP NNG17621139R

CONTRACT NUMBER TBD

This model represents the thermal environment surrounding the WFI instrument:

• Most temperature controlled surfaces related to the telescope are represented as fixed boundary conditions.

• The Spacecraft top deck is also a boundary temperature.

• The Coronagraph instrument is also held as a set of boundary temperatures.

• The Solar Array/Sunshield, Outer Barrel Assembly, and Instrument Carrier temperatures vary as a function of sun angle.

• The Facility Cryo Radiator is also included. Two methods exist for providing cooling to the focal planes:

o Method A: connect the focal planes directly to the radiator via a vendor selected transport method.

o Method B: utilize the load curves provided in the Requirements Document. If this approach is selected, boundary conditions of either heat or temperature at the radiator interface are necessary to reflect the proper radiator temperatures for backloading

• This model will provide for field of view blockages and proper shading of an Instrument design with reasonable surrounding temperatures for calculating the effect of infrared backloading.

This model can be provided upon request. The model is in Thermal Desktop version 5.8 format.