scholarly journals Optimum Disposition of Metal Particles in the Propellant Grain

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Leonid L. Minkov ◽  
Ernst R. Shrager ◽  
Elizaveta V. Pikushchak
Keyword(s):  
Metal Particle ◽  
Specific Impulse ◽  
Combustion Products ◽  
Combustion Efficiency ◽  
Metal Particles ◽  
Phase Flow ◽  
Solid Propellants ◽  
Two Phase ◽  
Cross Sectional ◽  
Metal Combustion

Using the dispersed metal in solid propellants to increase the temperature of combustion products leads to such a problem as the specific impulse loss due to the incomplete combustion of metal particles in the exhaust products. A redistribution of metal loaded into the propellant grain is one of the methods to decrease the specific impulse loss. This paper reports on the ways to obtain the optimum metal particle disposition for the case-bounded propellant grain of tube cross-sectional type. Three different approaches to analyze the metal combustion efficiency are discussed. The influence of the dynamic nonequilibrium of two-phase flow on the optimum metal particles disposition in the propellant grain of tube cross-sectional type is investigated.

Propellant Grain with Maximum Combustion Efficiency of Metal

2016 ◽  
Vol 685 ◽  
pp. 325-329
Author(s):  
Leonid Minkov ◽  
Ernst R. Shrager ◽  
Elizaveta V. Pikushchak
Keyword(s):  
Flow Field ◽  
Burning Rate ◽  
Combustion Efficiency ◽  
Metal Particles ◽  
Phase Flow ◽  
Two Dimensional ◽  
Two Phase ◽  
Cross Sectional ◽  
Analytical Correlation ◽  
Two Dimensional Flow

This paper reports on the ways of allocating the metal particles in the propellant grain of tube cross-sectional type to provide maximum combustion efficiency of metal. Two-dimensional flow field and the burning rate law govern a transport of the burning metal particles. The analytical correlation for the optimum allocation of metal particles in the case-bounded propellant grain of tube cross-sectional type under the assumption of equilibrium two-phase flow is deduced.

EFFECT OF BORON ON THE COMBUSTION CHARACTERISTICS OF METALLIZED HIGH-ENERGY MATERIALS

2020 ◽  
Author(s):  
A. Korotkikh ◽  
◽  
I. Sorokin ◽  
◽  
Keyword(s):  
Specific Impulse ◽  
Equilibrium Composition ◽  
Combustion Products ◽  
High Energy ◽  
Combustion Characteristics ◽  
Solid Propellants ◽  
Energy Materials ◽  
High Energy Materials ◽  
Condensed Combustion Products ◽  
Active Fuel Binder

The paper presents the results of thermodynamic calculations of the effect of pure boron additives on combustion characteristics of high-energy materials (HEM) based on ammonium perchlorate, ammonium nitrate, active fuel-binder, and powders of aluminum Al, titanium Ti, magnesium Mg, and boron B. The combustion parameters and the equilibrium composition of condensed combustion products (CCPs) of HEM model compositions were obtained with thermodynamic calculation program “Terra.” The compositions of solid propellants with different ratios of metals (Al/B, Ti/B, Mg/B, and Al/Mg/B) were considered. The combustion temperature Tad in a combustion chamber, the vacuum specific impulse J at the nozzle exit, and the mass fraction ma of the CCPs for HEMs were determined.

Heat Flux Measurement Method of Two-Phase Flow in SRM

2012 ◽  
Vol 152-154 ◽  
pp. 883-888
Author(s):  
Xiang Yu Zhang ◽  
Guo Qiang He ◽  
Pei Jin Liu ◽  
Jiang Li
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Two Phase Flow ◽  
Thermal Protection ◽  
Flux Measurement ◽  
Combustion Products ◽  
Phase Flow ◽  
Solid Rocket Motor ◽  
Two Phase ◽  
Heat Flux Measurement

Accurate information on heat transfer data of combustion products in the solid rocket motor chamber is a crucial prerequisite for the engine thermal protection. A measurement technique was well developed to acquire steady-state heat flux data of two-phase flow and was used successfully in the hostile environment. Experimental heat flux measurement has been obtained with an innovative designed instrument by simulating the flow field of complex charging configuration. The total heat flux of combustion products in the chamber was brought away by the coolant and calculated by its enthalpy rise in this device. The data could be used to analyze the heat transfer phenomena in SRMs and provide boundary condition for establishing insulation erosion model.

Simulation of Char Dust Combustion Inside a Pyroscrubber Downstream of a Petroleum Coke Calcining Kiln

2010 ◽  
Author(s):  
Lei Zhao ◽  
Ting Wang
Keyword(s):  
Energy Saving ◽  
Petroleum Coke ◽  
Gas Flow ◽  
Flame Temperature ◽  
Combustion Efficiency ◽  
Energy Output ◽  
Combustion Model ◽  
Phase Flow ◽  
Two Phase ◽  
Particle Combustion

A pyroscrubber is a furnace used in the petroleum coke calcining industry to recover energy from the carbonaceous contents, including char dust and hydrocarbon volatiles of the exhaust gas from the calcination kiln. The combusted hot gases are used to generate steam and produce electricity, so it is important to optimize the pyroscrubber performance to produce high-grade combusted gases to generate steam but with minimal emissions. A previous study employed the locally-homogeneous flow (LHF) model to study rhe means to improve combustion efficiency and reduce emissions. In the LHF model, the inter-phase exchange rates of mass, momentum and energy are assumed to be infinitely fast, so the dispersed phase (char dust) can be simplified as the gas phase, and the complex two-phase flow is then treated as a single-phase flow. In this study, LHF model is replaced with a solid particle combustion model by incorporating both finite-rate heterogeneous and homogeneous combustion processes. Results reveal that the particle combustion model generates much higher local flame temperature (2200K) than in LHF model (1800K). All char particles are burned before or in the high-bay area. Total energy output of the case with particle combustion model is 92% of the LHF model. Furthermore, motivated by the potential energy saving from removing the air blower power supply, this study further investigates the possible benefit of running the pyroscrubber with the ventilation doors open. Three cases with different combinations of air injections and door opening have been studied. Results show that the gas flow is stably stratified with a large amount of the entrained cold air moving at the bottom of the chamber and the hot combusted gas moving through the top. With bottom doors completely open, sufficient air can be drawn into the pyroscrubber without the need of blowing air in, but the combustion gases will be overcooled making this practice unfavorable from the energy saving point of view.

Visualization method for cross-sectional two-phase flow structure during the condensation of steam in a tube

2016 ◽  
Vol 20 (3) ◽  
pp. 591-605 ◽  
Author(s):  
Andree Pusey ◽  
Dongeok Kim ◽  
Hyun-Sik Park ◽  
Tae-Soon Kwon ◽  
Hyungdae Kim
Keyword(s):  
Flow Structure ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Visualization Method ◽  
Two Phase ◽  
Cross Sectional

scholarly journals 3D Reconstruction of Slug Flow in Mini-Channels with a Simple and Low-Cost Optical Sensor

Sensors ◽  
2019 ◽  
Vol 19 (20) ◽  
pp. 4573
Author(s):  
Huajun Li ◽  
Yandan Jiang ◽  
Haifeng Ji ◽  
Guangyu Liu ◽  
Shanen Yu
Keyword(s):  
3D Reconstruction ◽  
Optical Sensor ◽  
Slug Flow ◽  
Low Cost ◽  
Phase Flow ◽  
Two Phase ◽  
Cross Sectional ◽  
3D Images ◽  
Mini Channels ◽  
2D Images

The present work provides a new approach for 3D image reconstruction of gas-liquid two-phase flow (GLF) in mini-channels based on a new optical sensor. The sensor consists of a vertical and a horizontal photodiode array. Firstly, with the optical signals obtained by the vertical array, a measurement model developed by Support Vector Regression (SVR) was used to determine the cross-sectional information. The determined information was further used to reconstruct cross-sectional 2D images. Then, the gas velocity was calculated according to the signals obtained by the horizontal array, and the spatial interval of the 2D images was determined. Finally, 3D images were reconstructed by piling up the 2D images. In this work, the cross-sectional gas-liquid interface was considered as circular, and high-speed visualization was utilized to provide the reference values. The image deformation caused by channel wall was also considered. Experiments of slug flow in a channel with an inner diameter of 4.0 mm were carried out. The results verify the feasibility of the proposed 3D reconstruction method. The proposed method has the advantages of simple construct, low cost, and easily multipliable. The reconstructed 3D images can provide detailed and undistorted information of flow structure, which could further improve the measurement accuracy of other important parameters of gas-liquid two-phase flow, such as void fraction, pressure drop, and flow pattern.

Research on Measurement of Void Fraction for Vertically Rising Pipes by Optical Fiber Probe

2011 ◽  
Vol 361-363 ◽  
pp. 671-675 ◽  
Author(s):  
Feng Yun Chen ◽  
Wei Min Liu
Keyword(s):  
Optical Fiber ◽  
Void Fraction ◽  
Two Phase Flow ◽  
Exponential Model ◽  
Phase Flow ◽  
Two Phase ◽  
Cross Sectional ◽  
Fiber Probe ◽  
Optical Fiber Probe ◽  
Oil Gas

A way of measuring the average cross-sectional void fraction for vertically rising oil pipes by using closing valves quickly and optical fiber probe has been researched. Experiments were performed in oil-gas two-phase flow and the range of the average void fraction is 0.1～0.5. The relationship between average cross-sectional void fraction of a oil-gas two-phase flow and pipe’s center void fraction in vertically rising oil pipes, for different pipe diameters and varying oil flow, is obtained. An exponential model of average void fraction is also obtained with reference to Bankoff’s[1] variable density model. It is found that local void fraction reduces from center in radial direction and the local void fraction maximum value appears in the pipe’s center.

Study of Behavior of Two Phase Flow in Vertical Large Diameter Pipe

2010 ◽  
Author(s):  
Mohammad Hassan Kebriayi ◽  
Hadi Karrabi ◽  
Mohsen Rezasoltani ◽  
M. H. Saidi
Keyword(s):  
Void Fraction ◽  
Two Phase Flow ◽  
Flow Behavior ◽  
Large Diameter ◽  
Petroleum Industry ◽  
Phase Flow ◽  
Empirical Correlations ◽  
Two Phase Flows ◽  
Two Phase ◽  
Cross Sectional

Knowledge of Air-water two phase flows is significant to different engineering systems such as chemical reactors and power plant and petrochemical and petroleum industry. One of the most industrial cases of two phase flow is two phase flow in vertical large pipes. In this paper in order to find two phase flow behavior along vertical large diameter pipes we simulate air inlets with different number of holes and different hole diameters in the same flow rate of air. In addition, flow characteristics such as cross-sectional void fraction and velocity and pressure were considered. To achieve this aim, main equations of flow have been developed for investigation of flow behavior in air-water two phase flows. 3-D numerical analyses were performed by a designed and written CFD package which is based on volume of fluid (VOF) approach. Geometries, which have been studied in this article, are round tubes with diameter of 5 cm and with length of 1 and 5 m. The fluid is assumed to be viscous and incompressible. The pressure-velocity coupling is obtained using the SIMPLEC algorithm. The results showed that at the entrance of the pipe the effect of air inlet geometry is significant while at the whole pipe this effect suppressed. Furthermore increasing the velocity at the inlet can increase average void fraction and decrease pressure loses along the pipe axis. Numerical results were compared with available empirical correlations and this comparison shows good agreement between this work and empirical correlations.

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