megalomania
May 31st, 2003, 10:49 AM
Alchemist
Frequent Poster
Posts: 211
From: Woodland hills,Ca.,L.A.
Registered: NOV 2000
posted 04-13-2001 03:46 PM
--------------------------------------------------------------------------------
Hello all,
I found this on the web! Thought I'd post it just for a conversation topic!
AIAA 98-3385
COMBUSTION OF HYDRAZINIUM NITROFORMATE BASED
COMPOSITIONS
J. Louwers * , G.M.H.J.L. Gadiot ‡
Research Group Rocket Technology, TNO Prins Maurits Laboratory
P.O. Box 45, 2280 AA Rijswijk, the Netherlands
M. Versluis § , A.J. Landman ¶ , Th. H. van der Meer # , D. Roekaerts **
Thermal and Fluids Sciences, Department of Applied Physics, Delft University of Technology
P.O. Box 5046, 2600 GA Delft, the Netherlands
ABSTRACT
The combustion of hydrazinium nitroformate (HNF) and HNF with additives has been studied in window bombs. HNF burns with a high regression rate (40 mm/s at 10 MPa) and a high burn rate exponent. A slope break is observed around 2 MPa (from n=0.95 to n=0.85). The surface temperature
increases with increasing pressure: at 0.1 MPa Ts=530K, and at 1 MPa Ts=680K. Thermocouple measurements show a bend in the condensed phase temperature profile. This bend is attributed to cracks that form during combustion. Samples containing 20% aluminum have about 30% higher burn rate at 1 MPa than neat HNF. At low pressures, a small amount of residue was found after combustion of these samples. However, at 2 MPa the pellets combust without residue. Samples containing 5% graphite have a constant pressure exponent, n=0.81. Around 10 MPa the burn rate becomes equal to that of neat HNF. Also paraffin-based combinations burn with a low pressure exponent n=0.81 at low pressures. At higher pressures an increase in the pressure exponent was found, n=1.09.
* Ph.D. student, corresponding author, email: louwers@pml.tno.nl, phone: +31-15-2843367, fax: +31-15-2843958
‡ Propulsion engineer
§ Research fellow
¶ Student
# Associate professor
** Professor
Copyright © 1998 by TNO-Prins Maurits Laboratory and Delft University of Technology. Published by the
American Institute of Aeronautics and Astronautics, Inc. with permission.
INTRODUCTION
More energetic propellants may increase the
payload mass of space launchers, and increase the range of missiles. Therefore there is a continuous effort to increase the performance of solid propellants. High performance propellants have high flame temperatures and combustion products with low molecular weight. Partially replacing the AP in
composite propellants by RDX and HMX increases the performance. However the performance can be further increased by replacing AP with “new” more energetic oxidizers like ammonium dinitramide
(ADN), hydrazinium nitroformate (N2H4×C(NO2)3,
HNF) and hexanitrohexaazaisowurtzitane (HNIW, or CL-20, not a real oxidizer, but an energetic filler like RDX and HMX) [1]. These new oxidizers are also chlorine-free, which reduces the impact on the environment compared to AP-based compositions. Replacing the inert binders by energetic binders like
GAP, BAMO, PolyNimmo and PolyGlyn can further
increase the performance of these propellants.
HNF was part of a large research project for
new high-performance propellants in the United
States in the 60’s and 70’s. HNF appeared to be incompatible with the double bonds in unsaturated binders like HTPB [2]. The recent commercial production of saturated energetic binders like GAP, led to a renewed interest in HNF. Propellants based on hydrazinium nitroformate (HNF), an energetic binder like GAP or BAMO and aluminum have a substantially higher potential performance than any
other solid propellant [3]. Compared to AP-based propellants the performance gain is about 5…7%. In comparison with ADN-compositions, HNF-based American Institute of Aeronautics and Astronautics
------------------
fightclub
New Member
Posts: 39
From: none
Registered: APR 2001
posted 04-13-2001 07:40 PM
--------------------------------------------------------------------------------
Hydrazine nitroformate is old news, it is only its application in rocket propellants that it is a little new. It was easy to find:
Molecular formula: N2H5C(NO2)3
Molecular weight: 183.09 grams/mol
Density: 1.872g/ccm
Heat of formation: -72 kJ/mol
Melting point: 124°C
Friction sensitivity: 25-36 N
Impact sensitivity: 2-4 Nm
Passed UN test series III thermal stability test at 75°C
Toxicity (LD50): 128 mg/kg
Just looking on the web. It would be interesting to get the explosive properties it would probably be a brisant, high detonating explosive.
Frequent Poster
Posts: 211
From: Woodland hills,Ca.,L.A.
Registered: NOV 2000
posted 04-13-2001 03:46 PM
--------------------------------------------------------------------------------
Hello all,
I found this on the web! Thought I'd post it just for a conversation topic!
AIAA 98-3385
COMBUSTION OF HYDRAZINIUM NITROFORMATE BASED
COMPOSITIONS
J. Louwers * , G.M.H.J.L. Gadiot ‡
Research Group Rocket Technology, TNO Prins Maurits Laboratory
P.O. Box 45, 2280 AA Rijswijk, the Netherlands
M. Versluis § , A.J. Landman ¶ , Th. H. van der Meer # , D. Roekaerts **
Thermal and Fluids Sciences, Department of Applied Physics, Delft University of Technology
P.O. Box 5046, 2600 GA Delft, the Netherlands
ABSTRACT
The combustion of hydrazinium nitroformate (HNF) and HNF with additives has been studied in window bombs. HNF burns with a high regression rate (40 mm/s at 10 MPa) and a high burn rate exponent. A slope break is observed around 2 MPa (from n=0.95 to n=0.85). The surface temperature
increases with increasing pressure: at 0.1 MPa Ts=530K, and at 1 MPa Ts=680K. Thermocouple measurements show a bend in the condensed phase temperature profile. This bend is attributed to cracks that form during combustion. Samples containing 20% aluminum have about 30% higher burn rate at 1 MPa than neat HNF. At low pressures, a small amount of residue was found after combustion of these samples. However, at 2 MPa the pellets combust without residue. Samples containing 5% graphite have a constant pressure exponent, n=0.81. Around 10 MPa the burn rate becomes equal to that of neat HNF. Also paraffin-based combinations burn with a low pressure exponent n=0.81 at low pressures. At higher pressures an increase in the pressure exponent was found, n=1.09.
* Ph.D. student, corresponding author, email: louwers@pml.tno.nl, phone: +31-15-2843367, fax: +31-15-2843958
‡ Propulsion engineer
§ Research fellow
¶ Student
# Associate professor
** Professor
Copyright © 1998 by TNO-Prins Maurits Laboratory and Delft University of Technology. Published by the
American Institute of Aeronautics and Astronautics, Inc. with permission.
INTRODUCTION
More energetic propellants may increase the
payload mass of space launchers, and increase the range of missiles. Therefore there is a continuous effort to increase the performance of solid propellants. High performance propellants have high flame temperatures and combustion products with low molecular weight. Partially replacing the AP in
composite propellants by RDX and HMX increases the performance. However the performance can be further increased by replacing AP with “new” more energetic oxidizers like ammonium dinitramide
(ADN), hydrazinium nitroformate (N2H4×C(NO2)3,
HNF) and hexanitrohexaazaisowurtzitane (HNIW, or CL-20, not a real oxidizer, but an energetic filler like RDX and HMX) [1]. These new oxidizers are also chlorine-free, which reduces the impact on the environment compared to AP-based compositions. Replacing the inert binders by energetic binders like
GAP, BAMO, PolyNimmo and PolyGlyn can further
increase the performance of these propellants.
HNF was part of a large research project for
new high-performance propellants in the United
States in the 60’s and 70’s. HNF appeared to be incompatible with the double bonds in unsaturated binders like HTPB [2]. The recent commercial production of saturated energetic binders like GAP, led to a renewed interest in HNF. Propellants based on hydrazinium nitroformate (HNF), an energetic binder like GAP or BAMO and aluminum have a substantially higher potential performance than any
other solid propellant [3]. Compared to AP-based propellants the performance gain is about 5…7%. In comparison with ADN-compositions, HNF-based American Institute of Aeronautics and Astronautics
------------------
fightclub
New Member
Posts: 39
From: none
Registered: APR 2001
posted 04-13-2001 07:40 PM
--------------------------------------------------------------------------------
Hydrazine nitroformate is old news, it is only its application in rocket propellants that it is a little new. It was easy to find:
Molecular formula: N2H5C(NO2)3
Molecular weight: 183.09 grams/mol
Density: 1.872g/ccm
Heat of formation: -72 kJ/mol
Melting point: 124°C
Friction sensitivity: 25-36 N
Impact sensitivity: 2-4 Nm
Passed UN test series III thermal stability test at 75°C
Toxicity (LD50): 128 mg/kg
Just looking on the web. It would be interesting to get the explosive properties it would probably be a brisant, high detonating explosive.