ASTM D2508-93

Standard Test Method for Solid Rocket Propellant Specific Impulse Measurements

SCOPE
1.1 This test method covers the measurement of solid propellant specific impulse values.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

General Information

• Status: Historical
• Publication Date: 31-Dec-1992
• Technical Committee: F07 - Aerospace and Aircraft

Relations

• Replaced By: ASTM D2508-93(2002) - Standard Test Method for Solid Rocket Propellant Specific Impulse Measurements (Withdrawn 2003)
• Effective Date: 15-Mar-1993

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn. Contact ASTM
International (www.astm.org) for the latest information.
An American National Standard
Designation: D 2508 – 93
Standard Test Method for
Solid Rocket Propellant Specific Impulse Measurements
This standard is issued under the fixed designation D2508; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
¯
1. Scope 3.3.5 average pressure over action time— P 5
a
E
*
Pdt/t .
1.1 This test method covers the measurement of solid
B a
3.3.6 measured specific impulse— I = I/m , which is
propellant specific impulse values. sp p
corrected to standard conditions in accordance with Section 8.
1.2 The values stated in SI units are to be regarded as the
standard. The values given in parentheses are for information
4. Summary of Test Method
only.
4.1 This test method sets forth the following:
2. Referenced Documents
4.1.1 A set of uniform designations to be used for the
calculations.
2.1 ASTM Standards:
4.1.2 Precautions to be taken in experimental techniques.
D2506 Terminology Relating to Solid Rocket Propulsion
4.1.3 Acceptable ranges of experimental conditions to as-
2.2 Military Specification:
sure good results.
MIL-STD-292C
4.1.4 Uniform procedures for correcting measured values to
3. Terminology
a standard of set conditions.
4.1.5 Limited thrust coefficient values for use with this
3.1 Definitions—Refer to Terminology D2506 or Military
practice.
Specification MIL-STD-292C.
3.2 Definitions of Terms Specific to This Standard:
5. Significance and Use
3.2.1 mass of propellant, m— , to be used in the calculation
p
5.1 It is recognized that the size and design of ballistic test
ofspecificimpulse,shallbethemassofpropellantchargedinto
motors affect the determination of propellant specific impulse,
the motor.
and it is not intended that results from this test method be used
3.2.1.1 An igniter correction shall be made, determined
to predict performance in motors of size or design widely
either by experiment or calculation, when the theoretical value
different from that tested.
of this correction exceeds 0.1%.
3.2.1.2 The difference between before and after firing
6. Procedure
weights shall be recorded as expended weight.
6.1 Assumeapressure-timeorthrust-timetraceasshownin
3.2.1.3 Thepercentagedifferencebetweenexpendedweight
Fig. 1.
and propellant weight shall be recorded as either inerts
6.2 The following experimental criteria is recommended to
expended (if the expended weight is higher) or residue re-
ensure meaningful values of I :
tained. Values less than 0.2% may be ignored. sp
6.2.1 Use a geometry that gives a relatively neutral
3.3 Symbols:
G
pressure-time trace, be essentially sliverless, and provides a
3.3.1 total impulse— I 5 * Fdt.
A
nominal 50-lb grain. A suggested method for achieving these
3.3.2 burning time— t 5 timefrom“ B”to“E”.
b
conditions is to use a thin-webbed cylindrical geometry with
3.3.3 action time— t 5 timefrom “ B”to“F”.
a
ends uninhibited.
¯
3.3.4 average pressure over burning time— P 5
b
E 6.2.2 Use a geometry that also gives a value for throat-to-
* Pdt/t .
B b
port area ratio ofJ=A /A of less than 0.35.
t p
This test method is under the jurisdiction of ASTM Committee F-7 on
Aerospace Industry Methods and is the direct responsibility of Subcommittee
F07.02 on Propellant Technology. Procedures (except for specific impulse corrections in Section 6) used in this
Current edition approved March 15 1993. Published May 1993. Originally practice were released by the Chemical Propulsion Information Agency, Johns
published as D2508–66. Last previous edition D2508–71(1980)e1. Hopkins University, Applied Physics Laboratory, Johns Hopkins Rd., Laurel, MD
Annual Book of ASTM Standards, Vol 15.03. 20707 in August 1968, and are identical in substance to Publication No. 174,
AvailablefromStandardizationDocumentsOrderDesk,Bldg.4SectionD,700 “Recommended Procedures for the Measurement of Specific Impulse of Solid
Robbins Ave., Philadelphia, PA 19111-5094. Propellants.”
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn. Contact ASTM
International (www.astm.org) for the latest information.
D 2508 – 93
All point and average pressure values shall be expressed and used in psia.
A = zero time, t .
B = time at which the chamber pressure, P , reaches 5 % of nominal value of P .
c a
C and D = points of tangency with the “equilibrium” portion of the trace essentially as illustrated.
E = point on the pressure-time curve found by the intersection with the bisector of the angle between the two tangent lines at web burn-out.
F = time that the pressure reaches 5= % of nominal value of P on the decaying portion of the curve.
a
Gv= time at the end of thrust, t.
f
FIG. 1 Locations of Points on the Pressure/Thrust-Time Curve
¯
6.2.3 Use nozzles that give values of P between 5.52 and symbol be used only for those tests which conform to all
a
7.58 MN/m (900 and 1100 psia) to minimize the pressure
aspects of the correction procedure as follows:
correction.
I 5 I [C ~standard!/C ~test!]
sps sp F F
6.2.4 Use nozzles with an expansion ratio near optimum,
7.2 C (standard)isafunctiononlyofthespecificheatratio
but such that no separation due to over-expansion takes place F
(g), and can be taken from Table 1 or calculated as in the
during the equilibrium burning time (see Fig. 1, C to D).
AnnexA1. C (test)canbecalculatedasinAnnexA1,orcanbe
6.2.5 Use nozzles that have a conical nozzle with exit cone F
taken from the following relationship:
half-angle of 15 6 1°.
6.2.6 Use nozzles that have graphite inserts.
¯
C ~test!5 C ~vacuum!2e ~P / P !
F F amb a
6.2.7 Usenozzlesthathaveaconicalapproachhalfangleof
40 6 10°.
C (vacuum) = function of g and e obtained from Table 1,
6.2.8 Usenozzlesthathaveanozzleconvergenceratio(inlet
F
Fig. 2, or Fig. 3,
area/throat area) greater than three.
e = nozzle expansion ratio A /A,
6.2.
...