ESA Document - Emits - ESA

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HMM
Assessment Study
Report: CDF-20(A)
February 2004
page 224 of 422
point and the feet at the outer radius. In this way, the required ‘g’ environment is experienced at
the feet with a decreasing ’g’-gradient towards the head. Table 3-50 and Figure 3-68 show the
required rotation speed for a given ‘g’-load at the feet and also the resulting rotational
momentum
Min. Spin up Max. Spin-up Momentum
g-load RPM time (sec) torque [Nm] [Nm.s]
0.38 13.03715 7.5 179.9270925 1349.45319
1 21.14905 20 109.4551074 2189.10215
2 29.90927 40 77.39644869 3095.85795
3 36.63123 60 63.19393573 3791.63614
4 42.2981 80 54.72755371 4378.2043
Momentum [Nm.s]
5000
4000
3000
2000
1000
0
Table 3-50: Required rotation speed for a given g-load
Rotation Momentum
0 1 2 3 4 5
g-load
Figure 3-68: Rotation momentum
The rotational momentum can be compensated by a counter rotating mass of about 305 kg at a
radius of 1.8 m. This results in an estimated additional mass of 500 kg including the static
assembly and structure.
3.3.8.3.4.1 Budgets
The mechanism budgets are shown in Table 3-51 to Table 3-53, which represent the model
outputs: