NEPE Propellant Ignition and Combustion under Laser Irradiation

2014 ◽  
Vol 1042 ◽  
pp. 10-14 ◽  
Author(s):  
Hong Mei Wang ◽  
Xiong Chen ◽  
Chao Zhao
Keyword(s):  
Heat Flux ◽  
Laser Irradiation ◽  
Ignition Delay ◽  
Delay Time ◽  
Ignition Delay Time ◽  
Flame Temperature ◽  
Heat Fluxes ◽  
Short Delay ◽  
Laser Heat ◽  
Nepe Propellant

An experimental study was conducted to get the ignitibility of NEPE propellant under different CO2 laser heat fluxes. The combustion flame temperature distribution of NEPE propellant was measured using an infrared thermometer. Results show that the ignition delay time tends to decrease with the increase of laser heat flux, and there exists a significant value. The ignition delay time decreases fast when the heat flux is less than this value, but varies little when the heat flux is greater than this value. Laser irradiation had a significant effect on the combustion of NEPE propellant and after the laser unloading, the flame temperature of the propellant dose not decline immediately, but fall rapidly after a short delay.

Study on Laser Ignition Characteristics of NEPE Propellant

2012 ◽  
Vol 549 ◽  
pp. 1037-1040
Author(s):  
Guo Qiang Zhu ◽  
Xiong Chen ◽  
Chang Sheng Zhou ◽  
Qi Jun Wu
Keyword(s):  
Heat Flux ◽  
Flux Density ◽  
Ignition Delay ◽  
Delay Time ◽  
Heat Flux Density ◽  
Ignition Delay Time ◽  
Laser Ignition ◽  
Ignition Process ◽  
Laser Heat ◽  
Nepe Propellant

The ignition process of NEPE propellant by a CO2 laser ignition system has been investigated experimentally. The effect of laser heat flux density on the ignition delay time of NEPE propellant was examined. The ignition delay time of NEPE propellant was decreased along with the increase of laser heat flux density. The effect of ignition heat flux density on ignition delay time decreases when the laser heat flux density is more than 290 W/cm2. This heat flux density value can be used as igniter design reference value. The ignition delay time increases dramatically along with the decrease of laser heat flux density when the laser heat flux density is lower.

THERMAL BEHAVIOR AND IGNITION OF HIGH-ENERGY MATERIALS CONTAINING B, ALB2, AND TIB2

2020 ◽  
Author(s):  
A. G. Korotkikh ◽  
◽  
V. A. Arkhipov ◽  
I. V. Sorokin ◽  
E. A. Selikhova ◽  
...  
Keyword(s):  
Heat Flux ◽  
Thermal Behavior ◽  
Flux Density ◽  
Ignition Delay ◽  
Delay Time ◽  
Heat Flux Density ◽  
Ignition Delay Time ◽  
High Energy ◽  
Energy Materials ◽  
High Energy Materials

The paper presents the results of ignition and thermal behavior for samples of high-energy materials (HEM) based on ammonium perchlorate (AP) and ammonium nitrate (AN), active binder and powders of Al, B, AlB2, and TiB2. A CO2 laser with a heat flux density range of 90-200 W/cm2 was used for studies of ignition. The activation energy and characteristics of ignition for the HEM samples were determined. Also, the ignition delay time and the surface temperature of the reaction layer during the heating and ignition for the HEM samples were determined. It was found that the complete replacement of micron-sized aluminum powder by amorphous boron in a HEM sample leads to a considerable decrease in the ignition delay time by a factor of 2.2-2.8 at the same heat flux density due to high chemical activity and the difference in the oxidation mechanisms of boron particles. The use of aluminum diboride in a HEM sample allows one to reduce the ignition delay time of a HEM sample by a factor of 1.7-2.2. The quasi-stationary ignition temperature is the same for the AlB2-based and AlB12-based HEM samples.

scholarly journals Study on the Ignition Process and Characteristics of the Nitrate Ester Plasticized Polyether Propellant

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Xiaoting Yan ◽  
Zhixun Xia ◽  
Liya Huang ◽  
Likun Ma ◽  
Xudong Na ◽  
...  
Keyword(s):  
Grain Size ◽  
Energy Density ◽  
Ignition Delay ◽  
Delay Time ◽  
Ignition Temperature ◽  
Ignition Delay Time ◽  
Ignition Process ◽  
Ignition Energy ◽  
Nitrate Ester ◽  
Nepe Propellant

In this study, a CO2 laser ignition experimental system was built to study the ignition process and characteristics of the Nitrate Ester Plasticized Polyether (NEPE) propellant. The effect of the energy density, ingredients, and the grain size distribution of the propellant on the ignition process was investigated using a CO2 laser igniter, a high-speed camera, and a tungsten-rhenium thermocouple. Four types of NEPE propellants were tested under different laser heat fluxes, and the ignition delay time, the ignition temperature, and the ignition energy were obtained. Experimental results show that the ignition process of the NEPE propellant can be divided into three stages, namely the first-gasification stage, the first-flame stage, and the ignition delay stage. When the energy density is lower than the ignition energy threshold, the ignition process cannot be achieved even under continuous energy loading. The increase of the energy density can lead to the decrease of the ignition delay time but has little effect on the ignition temperature. The ingredients and grain size distribution have great effects on both the ignition delay time and the ignition temperature. The grain size effect of aluminum is the largest compared with that of Ammonium Perchlorate (AP) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), while the grain size effect of AP is larger than that of HMX.

The Kinetic Model Including Singlet Oxygen and Ozone in Hydrogen-Air Mixture

2013 ◽  
Vol 772 ◽  
pp. 239-245
Author(s):  
Yan Nan Chang ◽  
Chang Hui Wang ◽  
Tong Guang Cheng
Keyword(s):  
Experimental Data ◽  
Kinetic Model ◽  
Singlet Oxygen ◽  
Ignition Delay ◽  
Delay Time ◽  
Ignition Delay Time ◽  
Flame Temperature ◽  
Combustion System ◽  
Basic Model ◽  
System A

To analysize the influence of singlet oxygen O2(a1Δg) and ozone O3on the hydrogen-air combustion system, a kinetic model must be defined. By simulating the ignition delay time, flame speed, flame temperature and the component changes of Starik model, GRI3.0 model, Konnov model and Mueller model using the software Chemkin4.1 and comparing the results with the experimental data, the Starik model is chosen as the basis of the study. Then singlet oxygen O2(a1Δg) and ozone O3is added in the basic model to form a new mechanism. The presence of singlet oxygen O2(a1Δg) and ozone O3is demonstrated to result in noticeable enhancement on flame propagation.

Auto-ignition characteristics of diesel fuel in an O2–CO2 mixture

2019 ◽  
Vol 43 (1) ◽  
pp. 1-12
Author(s):  
Yongfeng Liu ◽  
Tianpeng Zhao ◽  
Zhijun Li ◽  
Fang Wang ◽  
Shengzhuo Yao ◽  
...  
Keyword(s):  
Diesel Fuel ◽  
Ignition Delay ◽  
Delay Time ◽  
Ignition Delay Time ◽  
Flame Temperature ◽  
Zone Model ◽  
Auto Ignition ◽  
Lift Off ◽  
Ignition Characteristics ◽  
Set Up

To study diesel fuel auto-ignition in an O2–CO2 mixture, a TZ (temperature zone) model is proposed. The effect of O2 and CO2 on reaction rate is considered. The relationship between temperature and ignition delay time is obtained. Different reduced mechanisms based on steady-state assumptions are applied in three temperature zones (T ≤ 800 K, 800 K < T ≤ 1100 K, T > 1100 K). The TZ model is coupled to KIVA-3V code for simulation calculations. To support the simulations, a constant-volume combustion bomb test bench is set up to visualize diesel fuel auto-ignition in air (21%O2–79%N2), a 53%O2–47%CO2 mixture, and a 61%O2–39%CO2 mixture. Ignition delay time and the flame image in these three conditions are compared and analyzed. Then the flame temperature contour and the flame lift-off length in a 53%O2–47%CO2 mixture and a 61%O2–39%CO2 mixture are analyzed. The results show that diesel fuel auto-ignition can be achieved in the tested O2–CO2 mixture. The TZ model can predict the auto-ignition characteristics of diesel fuel in a 53%O2–47%CO2 mixture and a 61%O2–39%CO2, with errors of 12% and 10%, respectively. In these two conditions, the ignition delay time and flame lift-off length are shorter than they are in air.

scholarly journals Single Droplet Combustion Characteristics of Petroleum Diesel- Philippine Tung Biodiesel Blends

2021 ◽  
Vol 18 (24) ◽  
pp. 1409
Author(s):  
Nurkholis Hamidi ◽  
Joko Nugroho
Keyword(s):  
Burning Rate ◽  
Ignition Delay ◽  
Delay Time ◽  
Ignition Delay Time ◽  
Ambient Pressure ◽  
Flame Temperature ◽  
Combustion Characteristics ◽  
Chamber Pressure ◽  
Droplet Combustion ◽  
Fuel Blends

The purpose of the present study is to investigate the effects of fuel blending of petroleum diesel and biodiesel made from Philippine Tung on the combustion characteristics of fuel droplets. In this study, petroleum diesel was mixed with biodiesel at volume percentages of 0 to 100 % to produce 5 fuel blends. The ratios of fuel blends (petroleum volume/biodiesel volume) were 100:0 (P100), 75:25 (BP25), 50:50 (BP50), 25:75 (BP75) and 0:100 (B100). Single droplet combustion experiments were prepared to understand the combustion characteristics at 3 levels of ambient pressure (100, 200 and 300 kPa). Observations were carried out on the ignition delay time, the burning rate constant, droplet temperature, and the flame visualization. The results showed some effects of the adding of biodiesel in petroleum diesel and the chamber pressure on droplet combustion characteristics.  The adding of biodiesel into petroleum diesel resulted in a shorter ignition delay time and higher burning rate constants. But, the lower heating value of biodiesel caused the lower flame temperature. The possibility of micro-explosion also increased due to the mixing of fuel. On the other hand, increasing the chamber pressure also resulted in shorter ignition delay, higher burning rate, and higher combustion temperature. The higher ambient pressure also compressed the flame dimension and enhanced the onset of micro-explosion. HIGHLIGHTS The adding of biodiesel into petroleum diesel with different physical and chemical properties impacts the droplet combustion behavior, especially on the characteristics of burning rate, ignition delay time, flame temperature, and micro explosion The high content of unsaturated fatty acids and oxygen in Philippine Tung biodiesel improves the ignition delay time and burning rate constants of the blended fuel, but, the lower heating value causes the lower flame temperature The multi-components of fatty acids with different boiling points in Philippine Tung oil promote the micro-explosion in the combustion of the mixtures of biodiesel and petroleum diesel fuel GRAPHICAL ABSTRACT

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