scispace - formally typeset
Search or ask a question
Topic

Burn rate (chemistry)

About: Burn rate (chemistry) is a research topic. Over the lifetime, 847 publications have been published within this topic receiving 8908 citations. The topic is also known as: Burning rate.


Papers
More filters
Proceedings ArticleDOI
01 Jan 1999
TL;DR: In this paper, the combustion of hydrazinium nitroformate (HNF) sandwiches and HNF propellants has been studied in window bombs, and the results show that GAP actively participates in the combustion, whereas HTPB does not contribute to the combustion.
Abstract: The combustion of hydrazinium nitroformate (HNF) sandwiches and HNF propellants has been studied in window bombs. Sandwich experiments were carried out up to 1 MPa. The binder in HNFIGAP sandwiches regresses along with the HNF. At the interface of GAP and HNF the regression rate is higher than that of neat HNF. Results of kinetic modeling of the HNF/GAP sandwich structure confii that the final flame temperature is reached closer to the burning surface above the binder slab. The binder in HNIVHTPB sandwiches does not keep up with the oxidizer. The extension above the burning surface is dependent on the pressure. At increasing pressures, the protrusion decreases. HNF/GAP propellants with both coarse and fine (474ym and 1OOpm based on sphere volume) were made with a solid loading of 55%. Both propellants have a burn rate exponent n=O.68+0.02. The difference in burn rate is very small: the propellant with fine HNF burns 4% faster at 5 MPa. The burn rate exponent of a HNF/HTPB propellant containing 73% HTPB is n=1.01+0.05. The HTPB propellant has a lower regression rate thanathe GAP propellant. The sandwich and propellant results show that GAP actively participates in the combustion, whereas HTPB does not contribute to the combustion. NO*, OH* and CN* emission images show that only the GAP sandwich has a clear diffusion flame, close enough to the surface to affect burning rate. Emission images of propellants containing coarse HNF show that only part of the surface is burning simultaneously. The propellant containing fine HNF has a more homogeneous emission from the surface.

2 citations

Patent
20 Dec 2005
TL;DR: In this article, a method and system for controlling oxygen levels in exhaust gases emitted from an i.c. engine adjusts the amount of cooled EGR and non-cooled EGR to allow the temperature of the exhaust gases to be controlled in order to achieve a desired temperature for regeneration of a particulate filter.
Abstract: A method and system for controlling oxygen levels in exhaust gases emitted from an i.c. engine adjusts the amount of cooled EGR and non-cooled EGR to allow the temperature of the exhaust gases to be controlled in order to achieve a desired temperature for regeneration of a particulate filter. The exhaust gas recirculation may be directed and controlled through an EGR cooler, an air cooler, as well as a cooler bypass to achieve the desired exhaust gas temperature. Also disclosed is a method which includes controlling the oxygen levels as a function of the soot burn rate of the filter, and a method which includes monitoring these rates during regeneration to prevent an uncontrolled soot burn rate condition.

2 citations

Patent
22 Sep 2000
TL;DR: In this paper, a phase-stabilized ammonium nitrate and fibrous cellulose propellant is used for an inflator used in a vehicle for inflating an air bag, with a relatively low burn rate exponent of no greater than about 0.7.
Abstract: A propellant composition that results in a desirable gas output when combusted is provided. The propellant can be part of an inflator used in a vehicle for inflating an air bag. The propellant has a relatively low burn rate exponent of no greater than about 0.7. The propellant is substantially dense, with the propellant having a density that is at least 85 % of theoretical density. The process of forming the propellant includes mixing the propellant composition in a mixing vessel (30), extruding the propellant composition into a propellant having a first density in an extrusion machine (40), drying the extruded propellant in a dryer (50), and flattening the dryed propellant to a controlled thickness using a roller mill (60) to provide a propellant having a second greater density correponding to the final density. The propellant preferably includes phase-stabilized ammonium nitrate and fibrous cellulose.

2 citations

Proceedings ArticleDOI
06 Jul 1997
TL;DR: In this paper, solid oxidizer HNF, hydrazinium nitroformate, crystals were pressed into pellets and burned as a monopropellant in the laser recoil device at pressures from 1 to 6 atm.
Abstract: Solid oxidizer HNF, hydrazinium nitroformate, crystals were pressed into pellets and burned as a monopropellant in the laser recoil device at pressures from 1 to 6 atm. The laser flux was set at 2 different mean power levels with sinusoidal oscillations of 21 ± 11.5 W/cm2 or 52 ± 5.9 W/cm2. Oscillations were logarithmically swept over the range from 4 to 80 Hz. A Russian inductive force transducer was used in these tests. The force transducer has a resonant frequency at 140 Hz, but performs well at frequencies below 100 Hz. HNF pellets were inhibited with a glass ring on the sample pedestal. HNF burns nicely with a steep burn rate slope of 0.892 down to 5 psia. Burn rate vs. laser flux was measured up to 60 W/cm2 at 1,2, 3,4, and 6 atm pressure. The slope of the bum rate vs laser flux was nearly the same at each pressure. At one atmosphere the rate vs. flux slope of HNF is slightly lower than HMX and about the same rate as HMX. Ignition times decreased from 760 ms to 78 ms as the laser flux increased from 21 to 67 W/cm2. Ignition times also decreased as pressure increased. HNF thrust oscillations decreased from 65 to 20 mg/cm2 over the frequency range of 4 to 80 Hz. The thrust oscillations also decreased 50% in amplitude as the pressure increased to 4 atm. The thrust oscillations are about the same order of magnitude as for HMX, less than N5 and greater than RDX. A phase crossover frequency was not determined as it was below the 4 Hz frequency range of these tests. The phase lag decreased very slightly with pressure, but was nearly the same at low frequencies.

2 citations

01 Jun 1973
TL;DR: In this article, the rotating valve method of measuring the combustion response of solid propellants to small amplitude pressure oscillations was evaluated, and a theoretical analysis was conducted to relate combustion response function to measurable ballistic properties of the combustion chamber.
Abstract: : The rotating valve method of measuring the combustion response of solid propellants to small amplitude pressure oscillations were evaluated. The method is based on producing pressure oscillations in a small rocket motor by varying the area of a secondary exhaust nozzle in a periodic manner. This is accomplished by using a rotating value as the secondary orifice. The valve apparatus operates concurrently with a primary nozzle which controls the steady-state pressure. The frequency of the oscillations is determined by the rotational speed of the valve. A theoretical analysis was conducted to relate the combustion response function to measurable ballistic properties of the combustion chamber. (Modified author abstract)

2 citations


Network Information
Related Topics (5)
Combustion
172.3K papers, 1.9M citations
86% related
Internal combustion engine
130.5K papers, 1M citations
72% related
Heat transfer
181.7K papers, 2.9M citations
71% related
Reynolds number
68.4K papers, 1.6M citations
71% related
Laminar flow
56K papers, 1.2M citations
70% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202310
202220
202116
202015
201918
201811