Xin Liao

Research on energy characteristic prediction expert system for gun propellant

In order to estimate energy characteristics of gun propellant, which are hard to measure in experiments, an expert system for predicting the energy characteristic of gun propellant(ECPES) has been established based on a reasonable combustion model. The system has functions of energy characteristic estimation, knowledge management and formula optimization with characteristic constraints. ECPES is validated by experiments, and the result shows it could indicate energy characteristic of gun propellant, with an error less than 3%.

Construction and Effect of New Mechanical Structure in Traditional Nitroguanidine Propellants

ABSTRACT In order to improve the mechanical properties of nitroguanidine propellants, spheroidized nitroguanidine (SNGu) was mixed up with needle-shaped NGu (NSNGu) at different mass ratios. The results from tensile/compression tests showed that the addition of SNGu could improve compression properties of nitroguanidine propellants. At the NSNGu to SNGu ratio of 8:2, compression properties of the propellants exhibit an excellent promotion with the maximum increase of 25.2% at −40°C comparing against the value of the traditional propellants. Meanwhile, tensile properties of the new propellants at the same ratio were nearly equal to those of traditional propellants. The impacts of the morphology of NGus on the distribution density and orientation of the NGus were investigated by scanning electron microscopy (SEM). The aforementioned mechanical behavior of nitroguanidine propellants could be well explained by the results of closed-bomb tests. The difference of the total heat effect observed in the Differential Scanning Calorimeter (DSC) tests of the two NGus was calculated to be only 1.5%.

Modeling and Simulation of Interior Ballistics Based on Actual Combustion Characteristics of Propellants

A novel interior ballistic model was established by revising actual combustion characteristics describing the relationship between burned propellants (ψ) and pressure impulse (It). The discrepancy between theory and experiment for gas releasing of porous propellant was investigated. Furthermore, the model was tested for multiperforated propellants, with relative errors less than 1 and 3% for the maximum pressure and velocity, respectively, indicating that this is a good model to estimate the interior ballistics performance for multiperforated propellants.

Simulation Research of Interior Ballistics Performance for a New-Type Light Caliber Cannon

In order to make a precise interpret and research of interior ballistics performance for a new-type light caliber cannon, an interior ballistics mathematical and physical model was established, on the basis of two-phase flow interior ballistics theory and description of interior ballistic cycle. MATLAB software was used to conduct numerical simulation. Conclusion indicates that the simulation results manifest favorable consistency with the experiment results. Simulation results can comprehensively interpret the physical process in guns by pressure distribution, projectile velocity and gas temperature distribution.

Research on the Tensile Properties of Microcellular PS with Supercritical CO2

Separating the influence of relative density and cell diameter on the tensile properties is very important to the theory research on mechanic properties of microcellular foamed materials. In this article, differences of the influences of relative density and cell diameter on the tensile properties are identified by the foaming PS in constrained mold. The effects of relative density and foaming process conditions such as foaming temperature, foaming time and saturated pressure on the tensile strength and Youngs modulus are analyzed. The results show that relative density is the only structural variable of Youngs modulus and Youngs modulus is not relative to cell diameter. Youngs modulus is in proportion to relative density. Tensile stress of microcellular PS is in contrast to cell diameter, decreases with increasing foaming time and foaming temperature and increases with saturated pressure.

The Study on a Triple-Base Propellant Preparation and Combustion Performance

In order to improve the combustion performance of the nitroguanidine triple-base propellant and optimize its preparation technology, used the half solvent method to prepare a series of propellant samples with different solvent ratios, and used the close bomb experiment and scanning electron microscope (SEM) and other experiments to study the combustion performance and shrinkage rate. Results show that with the same formula but different solvent ratios, the internal structure and the shrinkage rate of the triple-base propellant were quite different, the solvent ratio 0.34 propellant’s combustion performance is quite good, and its formula was the best recipe.

Comparison between Microcosmic Characterizations of Propellants by SEM and AFM

In order to obtain more detailed microcosmic information of propellants, NG propellant for example, characterization ways and conclusion analysis via SEM and AFM were introduced respectively. After comparison analysis of two experimental results, AMF gained more quantitative measurement results, such as friction force, topography, force-distance

Simulated Annealing Algorithm Optimization of the Deterred-Coating Propellant Charge Design

In order to get better interior ballistic performance of deterred-coating propellant charge (DCPC), the simulated annealing algorithm optimization of DCPC carries out in this paper. The interior ballistic model of DCPC and its model of simulated annealing algorithm optimization are established based on the characteristics of deterred-coating propellant. Two key parameters of DCPC, the mass ratio of deterred-coating propellants to total propellants and the average perforation pressure of deterred-coating propellant，are optimized for the search of the maximum muzzle velocity under the restricting conditions of maximum chamber pressure and the maximum relative end point of combustion. The optimization results agree well with the standard charge parameters, which justifies the feasibility of the model.