Table of Content

31 December 1984, Volume 5 Issue 4

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Paper

Thermal Explosion and Times-to-Ignition in Systems with distributed Temperatures Ⅱ . The Influence of Reactant Consumption.

T, Boddington, Feng Changgen, P. Gray

1984, 5(4):  1-10.  doi:10.3969/j.issn.1000-1093.1984.04.001

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This paper studies the influence of reactant consumption on criticality and on times-to-ignition，following the previous paper. It is shown that the influence of reactant consumption is to modify the critical value for Frank-Kamenetskiiˊs parameter δ; the fractional increase is simply ф(g_w/B)^2/3，where the coefficient ф depends on the geometry and other factors. Some typical values are given and discussed. Similar modification and discussion are also given for times-to-ignition.

A Study of the Influence of Density and Grain-Size of Cloud of Particles on Drag Coefficient in Gas-Solid Two-Phase Flow

Zhou Yanhuang, Sun Xingchang, Yin Hebao, Chen Xingquan, Li Guang

1984, 5(4):  11-15.  doi:10.3969/j.issn.1000-1093.1984.04.002

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This paper presents the experiment results of drag coefficient of gas- solid interphase with Reynolds number Re from 10² to 10⁶， porosity ε from 0.45 to 0.98 and particle equiyalant diameter dp from 3 mm to 11 mm. The results are analysed and discussed concisely.

Some Nonlinear Dynamic Criteria of Free Flight Missiles

Dong Liang

1984, 5(4):  16-26.  doi:10.3969/j.issn.1000-1093.1984.04.003

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Effects of nonlinear Magnus， damping and pitching moments on free flight missiles are discussed in this paper. Nonlinear dynamic factor concept is given out first. There are 13 stability criteria about the missile motions. An extension of the method of Kryloff and Bogoliuboff is employed to obtain approximate solutions of the nonlinear differential equations of motion for the complex angle of attack. The solutions are theoretical models of determining aerodynamic coefficients from firing tests.

Mannich Reaction Diaminoacetone Hydrochloride with Formaldehyde and Polynitroalkanes

Hu Yunquan, Wang Guang ju

1984, 5(4):  27-33.  doi:10.3969/j.issn.1000-1093.1984.04.004

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Diaminoacetone hydrochloride was hydroxymethylated by formaldehyde at room temperature to give analdehyde-amino condensation compo- und( I ). The condensation of( I ) with polynitroalkanes and its deriva， tes (such as nitroform，fluorodinitromethane or potassium dinitroethylate) gave linear or cyclic Mannich bases. The nitrotion of these compounds gave the corresponding nitromines. Although the condensate of ( I ) with methylenedinitramine could not be nitrated，it reacted with polynitroalkanes in aqueous nitric acid to form the same products as the reaction of polynitroalkanes with ( I ). The relationship between the reactivity of the Mannich bases and its structure was also discussed.

Computing Backlash for the Transmitting Mechanism in Which the Difference in the Numoer of Teeth of the Meshing Gears Is Small

Zhou Anqi

1984, 5(4):  34-39.  doi:10.3969/j.issn.1000-1093.1984.04.005

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In this paper we pay more attention to the computing backlash analysis of the transmitting mechanism of involute planetary gears in which the difference in the number of teeth of the meshing gears is one, coefficient of the addendum is 0.7, meshing angular is 30° and the output shaft is shaft of pin kind. This paper discusses computing backlash of the gear pair and output mechanism of shaft of pin kind according to the requirement of tolerance of designing and manufacturing and the probable maximum and minimum values of backlash are precomputed, using probabilistic method. It is convenient for mechanical designers to choose a proper transmitting mechanism according to the designing requirement.

A New Method of Rocket Nozzle Design

Qiu Guangshen

1984, 5(4):  40-49.  doi:10.3969/j.issn.1000-1093.1984.04.006

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A new method of the solid propellant rocket nozzle design is presented. The method, based on the theory of non-symmetric flow in Lavol nozzle，aims first at the angle of reducing the gas dynamic misalignment, and then at the angle of efficiency. It doesn't contradict the traditional methods of nozzle design, but supplement them. It will help reduce the dispersion of impact of the free flight rocket.

Experimental Techniques and Analysis

Model DZC-I Projectile Nutation angle and Nutation Angular Velocity Measuring Device

Xi Yonghui,Liu Lina, Li Huiling

1984, 5(4):  50-57.  doi:10.3969/j.issn.1000-1093.1984.04.007

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In this paper we present our development of the DZC-1 measuring device，in which a modulated Q-laser characterised by higher frequency, higher energy and narrower bandwidth of impulsive flashes is included as its essential element. This device can clearly record, on a single sensitized dry plate, two instant imagines of a projectile at various nutation angles，thus introducing a new method in the measurement of projectile nutation angles and nutation angular velocities. This paper is mainly devoted to the description of operation principles,basic structures and features and technical characteristics of the DZC-1 device as well as the presentation of pictures of projectiles of different behaviours. Finally，a simple method for calculating nutation angles and some calculation results are also presented here.

Research Notes

Analysis of Opening Process about Longitudinal Folded Fin

Wang Guiyu

1984, 5(4):  58-64.  doi:10.3969/j.issn.1000-1093.1984.04.008

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