It assumes that CUTE encounter hard thermal environment
in the space.Therefore demands arise as follows.
· Grasp the range of operating temperature in the space
· Aarrange environment for CUTE to operate surely
· Improve the arrangement of each board
That is why we have got to thermal analysis
For future satellite development, it is important
to know real thermal environment of the satellite on the orbit.
Especially students have little information about the environment of the satellite
on the orbit.
So we put thermistors on CUTE to determine the heat environment for future.
This thermistors will let us know the heat environment of CUTE on the orbit.
We adopt PT5-51F as thermistor.
And refer to here
to get where the thermal measurement points are in CUTE.
We conducted calibration for the thermistors which are used in CUTE.
The range of temperature is -25〜30℃.As an example, we show the calibration curve
of one attached to battery.
We have done thermal analysis by a package software of finite element method.
To grasp the flow of heat,we simplified the model of BBM. And we did thermal analysis
The condition of that is as follows.
We adopt the model for thermal analysis as follows.
Also we define the name of each part of the model.
We conduct thermal analysis with the heat input is 13W in a wall1. This condition
is a part of heat vacuum examination.
Foremore we defined that space temperature is 3K. And we used the values of these
materials for CUTE as showed bellow.
|Heat conduction [W/m2]
|Specific heat [J/kg/K]
In addition we define other conditions as follows
· Emmisivity is equal reflectivity because of restriction
of package software which we use
· All emmisivity of each material toward outside of
CUTE is 0.9 for black paint,
the emmisivity of each material toward inside of CUTE
And the emmisivity of resin is 0.06.
· Regard the generation of heat of each element as
the generation of itself
· All surface that is regarded to have small area doesn't
· All initial temperature is 273K.
· The end time of analysis is 80000 second.
Then we'll show a part of the result of the heat vacuum examination.
And we'll show the result of thermal analysis.
Comparing the result of heat vacuum experiment
and thermal analysis, the result of analysis donot correspond to the one of
vacuum experiment completely. We could say that one of the reason is to hang
our CUTE by strings and wiring for thermistor
which are not taken into account in thermal analysis. We will store the skill
of thermal analysis with monitering temperature of CUTE on the orbit in future.
Considering the circumstances
we can estimate the max temperature is about 80 Celsius degree, and the mininum
temperature is -40 Celsius degree.
Actually this range of temperature will make for CUTE difficult to survive.
Especially power system will be severe.
Because allowance of range of operating temparature is extremely narrow. But
some error must be included to some extent because of assumption we difined.Error
evaluation will be neccesary.
Anyway severe thermal condition will be expected from this analysis.