ASTM D2508-93(2002)

Standard Test Method for Solid Rocket Propellant Specific Impulse Measurements (Withdrawn 2003)

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• Status: Withdrawn
• Publication Date: 14-Mar-1993
• Withdrawal Date: 21-Oct-2003
• ICS: 49.140 - Space systems and operations
• Technical Committee: F07 - Aerospace and Aircraft
• Drafting Committee: F07.90 - Executive

Relations

• Replaces: ASTM D2508-93 - Standard Test Method for Solid Rocket Propellant Specific Impulse Measurements
• Effective Date: 15-Mar-1993

Standards Content (Sample)

NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D 2508 – 93 (Reapproved 2002)
Standard Test Method for
Solid Rocket Propellant Specific Impulse Measurements
This standard is issued under the fixed designation D 2508; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
¯
1. Scope
3.3.4 average pressure over burning time— P 5
b
E
*
Pdt/t .
1.1 This test method covers the measurement of solid B b
¯
3.3.5 average pressure over action time— P 5
propellant specific impulse values.
a
E
* Pdt/t .
1.2 The values stated in SI units are to be regarded as the
B a
3.3.6 measured specific impulse—I = I/m , which is cor-
standard. The values given in parentheses are for information
sp p
rected to standard conditions in accordance with Section 8.
only.
4. Summary of Test Method
2. Referenced Documents
2.1 ASTM Standards: 4.1 This test method sets forth the following:
4.1.1 A set of uniform designations to be used for the
D 2506 Terminology Relating to Solid Rocket Propulsion
2.2 Military Specification: calculations.
4.1.2 Precautions to be taken in experimental techniques.
MIL-STD-292C
4.1.3 Acceptable ranges of experimental conditions to as-
3. Terminology
sure good results.
3.1 Definitions—Refer to Terminology D 2506 or Military 4.1.4 Uniform procedures for correcting measured values to
Specification MIL-STD-292C. a standard of set conditions.
3.2 Definitions of Terms Specific to This Standard: 4.1.5 Limited thrust coefficient values for use with this test
3.2.1 mass of propellant, m —to be used in the calculation method.
p
of specific impulse, shall be the mass of propellant charged into
5. Significance and Use
the motor.
5.1 It is recognized that the size and design of ballistic test
3.2.1.1 An igniter correction shall be made, determined
motors affect the determination of propellant specific impulse,
either by experiment or calculation, when the theoretical value
and it is not intended that results from this test method be used
of this correction exceeds 0.1 %.
to predict performance in motors of size or design widely
3.2.1.2 The difference between before and after firing
different from that tested.
weights shall be recorded as expended weight.
3.2.1.3 The percentage difference between expended weight
6. Procedure
and propellant weight shall be recorded as either inerts
6.1 Assume a pressure-time or thrust-time trace as shown in
expended (if the expended weight is higher) or residue re-
Fig. 1.
tained. Values less than 0.2 % may be ignored.
6.2 The following experimental criteria is recommended to
3.3 Symbols:
G
ensure meaningful values of I :
3.3.1 total impulse— I 5 * F dt. sp
A
6.2.1 Use a geometry that gives a relatively neutral
3.3.2 burning time— t 5 time from “ B”to“E”.
b
pressure-time trace, be essentially sliverless, and provides a
3.3.3 action time— t 5 time from “ B”to“F”.
a
nominal 50-lb grain. A suggested method for achieving these
conditions is to use a thin-webbed cylindrical geometry with
ends uninhibited.
This test method is under the jurisdiction of ASTM Committee F07 on
Aerospace and Aircraft and is the direct responsibility of Subcommittee F07.09 on
Executive.
Current edition approved March 15 1993. Published May 1993. Originally Procedures (except for specific impulse corrections in Section 6) used in this
e1
published as D 2508 – 66. Last previous edition D 2508 – 71 (1980) . test method were released by the Chemical Propulsion Information Agency, Johns
Discontinued; See 1997 Annual Book of ASTM Standards, Vol 15.03. Hopkins University, Applied Physics Laboratory, Johns Hopkins Rd., Laurel, MD
Previously available from Standardization Documents Order Desk, Bldg. 4 20707 in August 1968, and are identical in substance to Publication No. 174,
Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098. This document was “Recommended Procedures for the Measurement of Specific Impulse of Solid
cancelled in 1974. Propellants.”
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D 2508 – 93 (2002)
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
6.2.2 Use a geometry that also gives a value for throat-to- this symbol be used only for those tests which conform to all
port area ratio of J=A /A of less than 0.35. aspects of the correction procedure as follows:
t p
¯
6.2.3 Use nozzles that give values of P between 5.52 and
a
I 5 I @C ~standard!/C ~test!#
sps sp F F
7.58 MN/m (900 and 1100 psia) to minimize the pressure
7.2 C (standard) is a function only of the specific heat ratio
F
correction.
(g), and can be taken from Table 1 or calculated as in the
6.2.4 Use nozzles with an expansion ratio near optimum,
Annex A1. C (test) can be calculated as in Annex A1, or can
F
but such that no separation due to over-expansion takes place
be taken from the following relationship:
during the equilibrium burning time (see Fig. 1, C to D).
¯
6.2.5 Use nozzles that have a conical nozzle with exit cone C ~test!5 C ~vacuum!2e ~P / P !
F F amb a
half-angle of 15 6 1°.
6.2.6 Use nozzles that have graphite inserts.
C (vacuum) = function of g and e obtained from Table 1,
F
6.2.7 Use nozzles that have a conical approach half angle of
Fig. 2, or Fig. 3,
40 6 10°.
e = nozzle expansion ratio A /A ,
e t
6.2.8 Use nozzles that have a nozzle convergence ratio (inlet
P = barometric pressure measured at time of
amb
area/throat area) greater than three.
firing, and
6.2.9 Use nozzles that have a ratio of wall radius of
curvature at the throat-to-throat diameter greater than two.
¯
P is defined in 3.3.5.
a
6.2.10 Use nozzles that are insulated.
6.2.11 Use weighing equipment and techniques that ass
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