QJ 809-1994 in English

Determination of thermal conductivity and specific heat capacity of composite solid propellants - Quasi-steady-state method

1 Subject content and application scope

This standard specifies the specimen, determination device, determination procedure, calculation and evaluation of determination results for determination of thermal conductivity and specific heat capacity of composite solid propellants by quasi-steady-state method.

This standard is applicable to the determination of thermal conductivity and specific heat capacity of composite solid propellants at room temperature. The determination of thermal conductivity and specific heat capacity of isotropic homogeneous materials with thermal conductivity of 0.1 ~ 5W/(m·K) may also be performed with reference.

2 Normative references

QJ 917 Determination of density of composite solid propellant, lining and thermal insulation materials

3 Principle

Quasi-steady state is a kind of dynamic steady state, which means that two sides of an infinite plate with a thickness of 2δ are heated by a constant heat flux, and after initial heat conduction, all parts of the plate are heated at the same rate, and the temperature difference between any two points in the thickness direction is constant. By determining the temperature difference between the two sides of the plate specimen in a quasi-steady state and the rate of temperature rise, the thermal conductivities and specific heat capacities of the specimen may be determined, respectively.

4 Specimen

4.1 Four specimens with the same shape and dimension are made from the materials under determination, the dimension shall be 100mm × 100mm × δ, and the thickness δ of the specimens is selected in the range of 10 ~ 15mm. The limit deviation of the thickness of the specimen shall be ±0.1mm.

4.2 The upper and lower sides of the specimens shall be parallel and flat, and the flatness and parallelism of the two planes shall not be greater than 0.1mm and 0.15mm, respectively.

1 Subject content and application scope
2 Normative references
3 Principle
4 Specimen
5 Determination device
6 Determination procedure
7 Calculation and evaluation of determination results
8 Test report
Additional explanation