Chemistry Reference
In-Depth Information
s
p
0,5
Fig. 4.3
Determination of
T
0
: analysis of data shown in Fig. 4.2 for the bottom section (
1
), the
middle section (
2
), and the top section (
3
), Δ
T
0
= 9
.
71
◦
C
Δ
The block calorimeter was standardized by the method of pulsed switching-on of
the internal heater (the measured constants are shown in Table 4.1). The temperature
dependence of (
MC
)
cal
is in good agreement with literature data on the temperature
dependence of the specific heat capacity (
C
=
C
(
T
)) for duralumin and copper. The
increase in the Bio number with increasing temperature is explained by the growth
of the irradiation contribution to the overall heat transfer through the Dewar vessel
walls.
Σ
Table 4.1
Block-calorimeter constants determined by the method of pulsed heating followed by
relaxation
Material of the block
Temperature,
◦
C
(Σ
MC
)
cal
,J(
◦
C)
−
1
Bi
10
−
4
Duralumin
130
621
3.2
×
10
−
3
485
750
1
.
1
×
10
−
4
Copper
400
1854
8.3
×
1
.
5
×
10
−
3
685
2125
values for a number of model polymer systems, com-
mercial hybrid propellants and some organic compounds are given.
In Tables 4.2 and 4.3,
Q
∑
4.2 Correlation Between the Burning Rates of Polymer Hybrid
Propellants and the Total Heats of Linear Pyrolysis
One of the most interesting aspects of polymer burning is the relationship between
its burning rate and its decomposition characteristics. The burning rates for some
materials have been measured (under the standardized conditions of the combustion
chamber of a model hybrid rocket engine) to check the conclusion about the dom-
inant role of the total heat of linear pyrolysis in the determination of the burning
