CN102279250A - Method for measuring burning velocity of solid propellant - Google Patents

Abstract

The invention provides a method for measuring the burning velocity of a solid propellant. In the method, the conventional burner is used; and after the solid propellant is arranged, the method comprises the following steps of: 1, measuring related parameters such as the total length L of the solid propellant, the embedding depth L1 of a thermoelectric couple, and a distance L2 between an ignition wire and the ignition end of the solid propellant; 2, acquiring burning data, and thus acquiring the temperature of the burning wave of the solid propellant and pressure in the process from igniting to complete burning; 3, calculating related moments, namely acquiring the igniting moment t1 of the propellant by using a pressure curve; and differentiating a burning wave curve, wherein a maximum value corresponds to a moment t2; and 4, calculating the burning velocity r by using a burning velocity formula shown in the specifications. By the method for measuring the burning velocity of the solid propellant, the conventional device is used, and the burning velocity of the solid propellant can be calculated by only measuring the related parameters of related lengths and moments, so that the method is low in using cost and easy to operate.

Description

A kind of solid propellant combustion rate measuring method

Technical field

The present invention relates to Aero-Space solid engines technical field, particularly a kind of method of measuring the propellant burning velocity of solid engines use.

Background technology

The combustion speed of measuring solid propellant is to manufacture and design the indispensable important step of solid propellant rocket.Along with the development of measuring technique, the method for measuring solid propellant combustion rate is more and more.Existing solid propellant combustion rate measuring method comprises target collimation method, acoustic-emission, Flame Image Process method, motor method etc.The current measuring methods measuring process is relative complex all, and cost is higher, and test number (TN) often is restricted.

Summary of the invention

The technical problem to be solved in the present invention is: the method that a kind of simple and effective measurement solid propellant combustion rate is provided.

Basic ideas of the present invention are: utilize the combustion wave that produces in the SOLID PROPELLANT COMBUSTION process, measure the temperature variation of solid propellant in the combustion process.The ultimate principle of utilizing is:

During the solid propellant stable state combustion, arbitrary cell cube is in the energy equilibrium state in the combustion wave, promptly meets following formula:

$\mathrm{\λ}\frac{d^{2}T}{d{x}^2}-\mathrm{c\ρr}\frac{\mathrm{dT}}{\mathrm{dx}}+Q=0$

In the following formula, parameter T is the combustion wave temperature; Ignore reaction heat source item Q, and following formula is carried out integration, can coagulate the phase temperature T respectively _sDistribute and the gas phase temperature T _fThe descriptive equation that distributes:

$T-T_0=(T_s-T_0)\exp \left(\frac{c_{\mathrm{pc}}{\mathrm{\ρ}}_c{r}_b}{{\mathrm{\λ}}_c}x\right)$ (formula one)

$T_f-T=(T_f-T_s)\exp (-\frac{c_{\mathrm{pg}}{\mathrm{\ρ}}_g{r}_g}{{\mathrm{\λ}}_g}x)$ (formula two)

X in above-mentioned two formulas is asked first order derivative, obtains following two formulas:

$\frac{d}{\mathrm{dx}}(T-T_0)=(T_s-T_0)\frac{c_{\mathrm{pc}}{\mathrm{\ρ}}_c{r}_b}{{\mathrm{\λ}}_c}\exp \left(\frac{c_{\mathrm{pc}}{\mathrm{\ρ}}_c{r}_b}{{\mathrm{\λ}}_c}x\right)$

$\frac{d}{\mathrm{dx}}(T_f-T)=-(T_f-T_s)\frac{c_{\mathrm{pg}}{\mathrm{\ρ}}_g{r}_g}{{\mathrm{\λ}}_g}\exp \left(\frac{c_{\mathrm{pg}}{\mathrm{\ρ}}_g{r}_g}{{\mathrm{\λ}}_g}x\right)$

When x=0, the curve intersection that above-mentioned two formulas are described, corresponding temperature is the combustion surface temperature of solid propellant.Therefore, the descriptive equation (being formula one and formula two) of combustion wave temperature is carried out a differentiate, can try to achieve the combustion surface temperature (i.e. the peak value of two combustion wave temperature curves) of solid propellant.

Based on above-mentioned principle, technical scheme of the present invention is: a kind of method of measuring solid propellant combustion rate comprises the steps:

Use burners in prior, solid propellant installed the back:

The first step: measure correlation parameter,

Measuring the solid propellant total length is that L, the thermopair depth of burying are L ₁, ignition wire and solid propellant ignition end distance be L ₂

Second step: gather the burning data,

After solid propellant lighted, utilize existing method, obtain the combustion wave temperature curve of solid propellant and the complete process of burning from lighting a fire in pressure curve;

The 3rd step: calculate the relevant moment,

Utilize pressure curve to obtain solid propellant and light t constantly ₁The combustion wave curve is carried out differential, record maximal value moment corresponding t ₂, this moment, corresponding combustion wave curve temperature was fired surface temperature exactly.

The 4th step: calculate the fast r of combustion,

Using the fast formula of combustion is:

Adopt the present invention can reach following technique effect: by measuring the correlation parameter in the SOLID PROPELLANT COMBUSTION process, the principle of utilizing the present invention to propose can obtain solid propellant combustion rate quickly and easily; The present invention utilizes existing apparatus, only needs to measure associated length and can calculate solid propellant combustion rate with correlation parameter constantly, and therefore use cost of the present invention is low, simple to operate.

Description of drawings

Fig. 1 is the schematic flow sheet of a kind of solid propellant combustion rate measuring method provided by the invention.

Embodiment

Below in conjunction with accompanying drawing invention is described further.

Fig. 1 is the schematic flow sheet of a kind of solid propellant combustion rate measuring method provided by the invention.As shown in the figure, use burners in prior, solid propellant is installed the back: the first step: measure correlation parameter, comprise that measuring the solid propellant total length with ruler is that L, the thermopair depth of burying are L ₁, ignition wire and solid propellant ignition end distance be L ₂Second step: gather the burning data, after solid propellant lighted, utilize thermopair to obtain the combustion wave temperature of solid propellant, the pressure transducer pressure in the complete process that obtains burn from lighting a fire, with utilize the combustion wave temperature curve of computing machine formation solid propellant after the above-mentioned data acquisition and the complete process of burning from lighting a fire in pressure curve; The 3rd step: calculate the relevant moment, utilize pressure curve to obtain propellant and light t constantly ₁The combustion wave curve is carried out differential, maximal value moment corresponding t ₂Corresponding combustion wave curve temperature is fired surface temperature exactly; The 4th step: calculate the fast r of combustion, the fast formula of application combustion is:

Claims (1)

1. a method of measuring solid propellant combustion rate is used burners in prior, after solid propellant is installed, it is characterized in that, comprises the steps:

The first step: measure correlation parameter,

Measuring the solid propellant total length is that L, the thermopair depth of burying are L ₁, ignition wire and solid propellant ignition end distance be L ₂

Second step: gather the burning data,

After solid propellant lighted, utilize existing method, obtain the combustion wave temperature curve of solid propellant and the complete process of burning from lighting a fire in pressure curve;

The 3rd step: calculate the relevant moment,

Utilize pressure curve to obtain solid propellant and light t constantly ₁The combustion wave curve is carried out differential, record maximal value moment corresponding t ₂

The 4th step: calculate the fast r of combustion,

Using the fast formula of combustion is:

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