Laser-Controlled Combustion of Solid Propellant

2014 ◽  
Vol 884-885 ◽  
pp. 87-90 ◽  
Author(s):  
Zhao Qin ◽  
Jiang Wu ◽  
Rui Qi Shen ◽  
Ying Hua Ye ◽  
Li Zhi Wu
Keyword(s):  
Burning Rate ◽  
Laser Irradiation ◽  
Power Density ◽  
Experimental Work ◽  
Laser Power ◽  
Solid Propellant ◽  
Pressure Effect ◽  
Laser Power Density ◽  
Back Pressure ◽  
Solid Propellants

This paper describes experimental work on laser-controlled combustion of solid propellants. Combustion of AP/HTPB, including ignition, combustion, extinction and re-ignition could be controlled by CO2 laser irradiation at the back pressure of 0.1, 0.3 and 0.5 MPa in nitrogen. Burning rate of propellant increased linearly with the increasing of laser power density. Vieilles law was used here to check pressure effect to burning rate, pressure exponent under different power density (except 0.5 MW/m2) are very close to 0.17.

Failure Behavior Tests of Preloaded T300/AG80 Composites Irradiated by Laser Beam

2012 ◽  
Vol 562-564 ◽  
pp. 171-174
Author(s):  
Li Ting Liu ◽  
Lian Chun Long ◽  
Zhong Ying Chen
Keyword(s):  
Laser Irradiation ◽  
Power Density ◽  
Laser Power ◽  
Composite Plate ◽  
High Speed ◽  
Failure Time ◽  
Experimental Testing ◽  
Laser Power Density ◽  
Failure Behavior ◽  
The Relationship

This paper predicts the effect of main parameters to the failure behavior of T300/AG80 composite plate under preload and laser irradiation by experimental testing and data fitting. The load holding device was used to give certain preload to composite plate specimens, and an Nd: YAG laser was used to give laser radiation simultaneously for testing the failure time of the specimens. By varying the magnitudes of preload and the laser power densities, the effect of preload and laser power density on the failure time is obtained. The reaction process was recorded with a high-speed camera. The experimental data were fitted to obtain the expression of the materials failure time with preload and laser power density. When the preload kept constant, the relationship between the failure time and laser power density was exponential function. When the laser power density kept constant, the relationship between the failure time and pre-tensile-loads was approximating linear, and pre-compress-load was quadratic. Fitting the empirical formula provides a reference to predict life for the composite structure applied both preload and the action of the laser irradiation.

scholarly journals Comparison of laser irradiation behavior of plasma-sprayed Ba2-xSrxSmTaO6 coatings

2020 ◽  
Author(s):  
Jiayi Zheng ◽  
Zhuang Ma ◽  
Yanbo Liu ◽  
Lihong Gao
Keyword(s):  
Laser Irradiation ◽  
Power Density ◽  
Laser Power ◽  
Melting Process ◽  
Damage Mechanism ◽  
Laser Power Density ◽  
Laser Damage ◽  
Back Surface ◽  
Air Plasma ◽  
Good Thermal Stability

Abstract Ba2 − xSrxSmTaO6 (x = 0–2), a series of low thermal conduction and good thermal stability materials, is believed to have potential use as thermal insulation laser protection materials, however, is limited by their unclear laser damage mechanism. Thus, in this paper, we investigated and compared their laser damage behaviors as well as their protection thresholds. The Ba2 − xSrxSmTaO6 (x = 0, 0.5, 1, 1.5 and 2) powder were prepared by solid state reaction and the coatings were prepared by air plasma spray. During the laser irradiation process, we observed that the coatings underwent irradiation center turning bright, grains recrystallization and melting process. When the laser power density was 500W/cm2, no damage was observed in all five components coatings and the ablation surface of x = 1 and 2 coatings turned bright. However, the melting phenomenon occurred to x = 0.5, 1, 1.5 and 2 coatings while the laser power density reached 1000W/cm2, and the ablation area of x = 0 coatings started to turn bright. At 1500W/cm2 laser power density, coatings of all five components melted and the melting area of x = 0 and 1 was obviously smaller than the coatings of other three components. Ba2SmTaO6 (x = 0) showed the highest protection threshold that was 2000W/cm2 for 10 s, and x = 0.5 coatings showed the lowest protection threshold that was 1000W/cm2 for 26 s. In terms of back surface temperature, BaSrSmTaO6 (x = 1) presented the lowest value and Ba2SmTaO6 was only slightly higher than it. To sum up, Ba2SmTaO6 has the best comprehensive laser protection properties and is believed to be the most potential laser protection materials among the five components.

scholarly journals Influence of Saturation Phenomena on Laser-Excited Atomic Fluorescence Flame Spectrometry

1973 ◽  
Vol 28 (2) ◽  
pp. 273-279
Author(s):  
J. Kühl ◽  
S. Neumann ◽  
M. Kriese
Keyword(s):  
Power Density ◽  
Laser Power ◽  
Atomic Emission ◽  
Equation Model ◽  
Laser Power Density ◽  
Atomic Level ◽  
Dye Laser ◽  
Atomic Fluorescence ◽  
Emission Flame ◽  
Flame Spectrometry

Using a simple rate equation model, the laser power density Ic necessary to reach 50% of the saturation limited population of the excited atomic level under typical flame conditions is calculated. For Na atoms aspirated into the flame a saturating power density for irradiation with a narrow dye laser line (bandwidth 0.033 Å) of Ic ~ 0.4 kW/cm2 was determined. With the aid of a dye laser with an appropriate laser power density, analytical curves for Na were measured yielding a detection limit of 0.2 ng/ml. This sensitivity is comparable with the best results obtained by atomic emission flame spectrometry.

Experimental Study on Testing Ni-Containing Stainless Steel Protective Coatings by Pulsed Laser Scratching

2010 ◽  
Vol 43 ◽  
pp. 651-656
Author(s):  
Ai Xin Feng ◽  
Yu Peng Cao ◽  
Chuan Chao Xu ◽  
Huai Yang Sun ◽  
Gui Fen Ni ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Power Density ◽  
Laser Power ◽  
Protective Coatings ◽  
Three Dimensional ◽  
Pulsed Laser ◽  
Laser Power Density ◽  
The Matrix ◽  
The Impact

In the experiment, we use pulsed laser to conduct discrete scratching on Ni-containing stainless steel protective coatings to test residual stress situation after the matrix is scratched; then to analyze the the impact of the impact stress wave on coating - substrate bonding strength according to the test results, finally to infer the laser power density range within which it occurs coating failure. The study shows that: after laser discrete scratching, the residual stress of the center of the laser-loaded point on matrix surface gradually reduces when the pulsed laser power density increases. The matrix produces a corresponding residual compressive stress under the laser power density reaches a certain value. The actual failure threshold values are 12.006 GW/cm2, 11.829GW/cm2 and 12.193GW/cm2 measured by the three-dimensional topography instrument testing the discrete scratch point of three groups of samples and verified by using a microscope

NUMERICAL SIMULATION OF COMBUSTION OF THE COMPOSITE SOLID PROPELLANT CONTAINING BIDISPERSED BORON POWDER

2021 ◽  
pp. 131-139
Author(s):  
V.A. Poryazov ◽  
◽  
K.M. Moiseeva ◽  
A.Yu. Krainov ◽  
◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Burning Rate ◽  
Solid Propellant ◽  
Mathematical Formulation ◽  
Solid Propellants ◽  
Boron Powder ◽  
Composite Solid Propellant ◽  
Composite Solid Propellants ◽  
Composite Solid ◽  
Propellant Surface

A problem of combustion of the composite solid propellants containing various powders of metals and non-metals is relevant in terms of studying the effect of various compositions of powders on the linear rate of propellant combustion. One of the lines of research is to determine the effect of the addition of a boron powder on the burning rate of a composite solid propellant. This work presents the results of numerical simulation of combustion of the composite solid propellant containing bidispersed boron powder. Physical and mathematical formulation of the problem is based on the approaches of the mechanics of two-phase reactive media. To determine the linear burning rate, the Hermance model of combustion of composite solid propellants is used, based on the assumption that the burning rate is determined by mass fluxes of the components outgoing from the propellant surface. The solution is performed numerically using the breakdown of an arbitrary discontinuity algorithm. The dependences of the linear burning rate of the composite solid propellant on the dispersion of the boron particles and gas pressure above the propellant surface are obtained. It is shown that the burning rate of the composite solid propellant with bidispersed boron powder changes in contrast to that of the composite solid propellant with monodispersed powder. This fact proves that the powder dispersion should be taken into account when solving the problems of combustion of the composite solid propellants containing reactive particles.

Numerical Simulation and Applications of a Method for Attenuating Laser Power Density

2013 ◽  
Vol 50 (2) ◽  
pp. 022201
Author(s):  
王振宝 Wang Zhenbao ◽  
冯国斌 Feng Guobin ◽  
杨鹏翎 Yang Pengling ◽  
冯刚 Feng Gang ◽  
闫燕 Yan Yan
Keyword(s):  
Numerical Simulation ◽  
Power Density ◽  
Laser Power ◽  
Laser Power Density

scholarly journals Investigation on Residual Stress Loss during Laser Peen Texturing of 316L Stainless Steel

2019 ◽  
Vol 9 (17) ◽  
pp. 3511 ◽  
Author(s):  
Kangmei Li ◽  
Yifei Wang ◽  
Yu Cai ◽  
Jun Hu
Keyword(s):  
Residual Stress ◽  
Compressive Stress ◽  
Power Density ◽  
Laser Power ◽  
Surface Deformation ◽  
Laser Power Density ◽  
Residual Compressive Stress ◽  
Laser Spot ◽  
Residual Tensile Stress ◽  
Spot Radius

Laser peen texturing (LPT) is a novelty way of surface texturing based on laser shock processing. One of the most important benefits of LPT is that it can not only fabricate surface textures but also induce residual compressive stress for the target material. However, the residual stress loss leads to partial loss of residual compressive stress and even causes residual tensile stress at the laser spot center. This phenomenon is not conducive to improving the mechanical properties of materials. In this study, a numerical simulation model of LPT was developed and validated by comparison of surface deformation with experiments. In order to investigate the phenomenon of residual stress loss quantitatively, an evaluation method of residual stress field was proposed. The effects of laser power density and laser spot radius on the residual stress, especially the residual stress loss, were systematically investigated. It is found that with the increase of laser power density or laser spot radius, the thickness of residual compressive layer in depth direction becomes larger. However, both the magnitude and the affecting zone size of residual stress loss will be increased, which implies a more severe residual stress loss phenomenon.

Potential Usage of Energetic Nano-sized Powders for Combustion and Rocket Propulsion

2003 ◽  
Vol 800 ◽  
Author(s):  
Kenneth K. Kuo ◽  
Grant A. Risha ◽  
Brian J. Evans ◽  
Eric Boyer
Keyword(s):  
Burning Rate ◽  
Energy Release ◽  
Solid Propellant ◽  
Nano Particles ◽  
Solid Fuels ◽  
Solid Propellants ◽  
Regression Rate ◽  
Combustion Behavior ◽  
Boron Particles ◽  
Ignition And Combustion

ABSTRACTNano-sized energetic metals and boron particles (with dimensions less than 100 nanometers) possess desirable combustion characteristics such as high heats of combustion and fast energy release rates. Because of their capability to enhance performance, various metals have been introduced in solid propellant formulations, gel propellants, and solid fuels. There are many advantages of incorporating nano-sized materials into fuels and propellants, such as: 1) shortened ignition delay; 2) shortened burn times, resulting in more complete combustion in volume-limited propulsion systems; 3) enhanced heat-transfer rates from higher specific surface area; 4) greater flexibility in designing new energetic fuel/propellants with desirable physical properties; 5) nano-particles can act as a gelling agent to replace inert or low-energy gellants; 6) nano-sized particles can also be dispersed into high-temperature zone for direct oxidation reaction and rapid energy release, and 7) enhanced propulsive performance with increased density impulse. In view of these advantages, numerous techniques have been developed for synthesizing nano-particles of different sizes and shapes. To reduce any possible hazards associated with the handling of nano-sized particles as well as unwanted particle oxidation, various passivation procedures have been developed. Some of these coating materials could enhance the ignition and combustion behavior, others could increase the compatibility of the particles with the surrounding material. Many researchers have been actively engaged in the characterization of the ignition and combustion behavior of nano-sized particles as well as the assessment of performance enhancement of propellants and fuels containing energetic nano-particles. For example, solid fuels could contain a significant percentage of nano-sized particles to increase the mass-burning rate in hybrid rocket motors, the regression rate of solid propellants can be increased by several times when nano-sized particles are incorporated into the formulation. Specifically, hybrid motor data showed that the addition of 13% energetic aluminum powders can increase the linear regression rate of solid HTPB-based fuel by 123% in comparison to the non-aluminized HTPB fuel at a moderate gaseous oxidizer mass flow rate. Strand burner studies of two identical solid propellant formulations (one with 18% regular aluminum powder and the other with 9% aluminum replaced by Alex® powder) showed that nano-sized particles can increase the linear burning rate of solid propellants by 100%. In addition to solid fuels and propellants, spray combustion of bipropellants has been conducted using gel propellants impregnated with nano-sized boron particles as the fuel in a rocket engine. High combustion efficiencies were obtained from burning nano-sized boron particles contained in a non-toxic liquid-fuel spray. Materials characterization such as chemical analyses to determine the active aluminum content, density measurements, and imaging using an electron microscope have been performed on both neat nano-sized particles and mixtures containing the energetic materials. In general, using energetic nano-sized particles as a new design parameter, propulsion performance of future propellants and fuels can be greatly enhanced.

Tuning the Defects in AgO Nanoparticles/Graphene Bilayers System by Laser Power Density

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
H. Ferreira ◽  
M. Briones2, M. Camilo ◽  
G. Poma ◽  
Maria Quintana ◽  
A. Champi
Keyword(s):  
Power Density ◽  
Laser Power ◽  
Laser Power Density
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