RU2601400C1 - Method of gas turbine engines mass production - Google Patents

Abstract

FIELD: turbo-machines.

SUBSTANCE: invention relates to turbomachinery, namely, to methods of gas turbine engines mass production stability evaluating. Said technical result is achieved due to that, for estimation of gas-turbine engines mass production stability one physical and mechanical parameter are selected at same mode for each of engines, then average arithmetic value of selected parameter is determined on selected mode Pcpj, followed by calculation of selected parameter unbiased dispersion on selected mode Sj², then checking compliance of empirical distribution parameter to normal distribution law, for this purpose selective coefficient of asymmetry A and selective kurtosis E are calculated, as well as values dA, dE characterizing engine empirical distribution parameter conformity to normal distribution law, and then, checking compliance of inequalities dA > 0, dE > 0 and Pcpj-2,5·Sj<Pij<Pcpj+2,5·Sj, wherein in case of above inequalities adherence, empirical distribution of selected parameter Ρ values on selected mode j is considered to be normal, and production is stable. In case of above-mentioned inequalities non-compliance engine production process, assembly and testing is checked for deviations, detecting and eliminating cause of non-conformity and evaluating stability of this method again.

EFFECT: technical effect is possibility to evaluate gas-turbine engines mass production stability at stage of acceptance tests.

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Description

The invention relates to the field of turbomachinery, and in particular to methods for assessing the stability of serial production of gas turbine engines.

As the closest analogue (prototype), the method of serial production of gas turbine engines was chosen, in which, during acceptance tests of the nth number of engines, physical and mechanical parameters are measured in different modes of each of the engines (RU 2555940 C2).

When implementing the known method, it is not possible to assess the stability of serial production of gas turbine engines, and, therefore, there is no way to control the quality of manufacture, assembly and testing of a batch of engines in general.

The technical result achieved by using the present invention is the ability to assess the stability of serial production of gas turbine engines at the stage of acceptance tests.

The specified technical result is achieved by the fact that in the known method for the serial production of gas turbine engines, in which a batch of engines is manufactured and assembled, and during acceptance tests of the nth number of engines, physicomechanical parameters are measured in various modes of each of the engines according to the present invention to assess stability serial production of gas turbine engines choose one physical and mechanical parameter in one mode for each of the engines, then determine the average the arithmetic value of the selected parameter in the selected Pcpj mode according to the formula:

где

Where

n is the number of engines;

i is the engine number;

j is the selected mode;

Pij - parameter value of the i-th engine in the j-th mode;

then calculate the unbiased dispersion of the selected parameter in the selected mode Sj ² according to the formula:

,

,

then check the correspondence of the empirical distribution of the parameter to the normal distribution law, for which the selected asymmetry coefficient A is calculated in accordance with the formula:

,

,

and a sample kurtosis coefficient E in accordance with the formula:

,

,

and also the quantities dA, dE, characterizing the correspondence of the empirical distribution of the engine parameter to the normal distribution law:

dA = 3 · Sa- | A |,

dE = 5 · Se- | E |,

where Sa, Se are the standard deviations of the asymmetry and excess, determined by the formulas:

,

,

,

,

then verify compliance with the inequalities dA> 0, dE> 0 and

Pcpj-2.5Sj <Pij <Pcpj + 2.5Sj,

in this case, if the above inequalities are observed, the empirical distribution of the values of the selected parameter Ρ in the selected mode j is considered normal, and the production is stable.

In the case of non-compliance with the above inequalities, check the production technology, assembly and testing of the engine for deviations, identify and eliminate the cause of the discrepancy, and re-evaluate the stability of production in this way.

The ability to assess stability at the stage of serial production of gas turbine engines, namely during acceptance tests, allows to ensure the quality of engine manufacturing and assembly, if necessary, make adjustments to the engine manufacturing technology and prevent defective engines from being used.

The proposed method for the production of gas turbine engines is implemented as follows.

Example 1

1. We make and assemble a batch of 10 engines in any known manner.

2. When conducting acceptance tests, we measure one of the physicomechanical parameters in one mode for each engine, for example, the high-speed rotor speed at maximum mode for each engine n _VD1 = 100.6%, n _VD2 = 100.1%, n _VD3 = 99.4%, n _VD4 = 101.1%, n _VD5 = 99.2%, n _VD6 = 99.5%, n _VD7 = 99.4%, n _VD8 = 100.0%, n _VD9 = 99.9%, n _VD10 = 98.1%.

3. We calculate the arithmetic mean value of the rotational speed of the high-pressure rotor at the maximum mode n _VDav = 99.7%.

4. We calculate the unbiased dispersion of the rotational speed of the high-pressure rotor at the maximum mode S ² = 0.6674.

5. We calculate the sample asymmetry coefficient A = -0.1979 and the sample excess coefficient E = -0.3445.

6. We calculate the standard deviations of the asymmetry Sa = 0.579 and kurtosis Se = 0.755.

7. We calculate the values dA = 1,540 and dE = 3,429.

8. Check compliance with the inequalities 97.7% <n _VD <101.8%, dA> 0 and dE> 0

9. Due to the fact that the parameters satisfy the above inequalities, we consider the empirical distribution of the values of the rotational speed of the high pressure rotor at maximum mode to be normal, and production to be stable. Therefore, a batch of engines can be sent into operation.

Example 2

1. We manufacture and assemble a batch of 8 engines in any known manner.

2. When conducting acceptance tests, we measure one of the physicomechanical parameters in one mode for each engine, for example, the air flow through the engine in full afterburner mode for each engine G _B1 = 122.3 kg / s, G _B2 = 122.5 kg / s, G _B3 = 122.4 kg / s, G _B4 = 118.4 kg / s, G _B5 = 122.5 kg / s, G _B6 = 121.9 kg / s, G _B7 = 122.3 kg / s, G _B8 = 121.5% kg / s.

3. Calculate the arithmetic mean value of the air flow in the full afterburner G _Bcp = 121.7 kg / s.

4. Calculate the unbiased dispersion of air flow in the full afterburner S ² = 1,922.

5. We calculate the sample asymmetry coefficient A = -1.884 and the sample excess coefficient E = 1.7705.

6. We calculate the standard deviations of the asymmetry Sa = 0.603 and kurtosis Se = 0.705.

7. We calculate the values dA = -0.075 and dE = 5.296.

8. Check compliance with the inequalities 116.9 kg / s <G _B <126.5 kg / s, dA> 0 and dE> 0.

9. Due to the fact that dA <0, the empirical distribution of air flow values does not correspond to the normal law, and production is unstable. Therefore, for a batch of engines, it is required to check the production technology, assembly and testing of the engine for deviations, identify and eliminate the cause of the discrepancy, and re-evaluate the stability of production in this way.

Claims (1)

A method of serial production of gas turbine engines, in which a batch of engines is manufactured and assembled, and during acceptance tests of the nth number of engines, physicomechanical parameters are measured in different modes of each engine, characterized in that one physicist is chosen to assess the stability of the serial production of gas turbine engines mechanical parameter in one mode for each of the engines, then determine the arithmetic mean value of the selected parameter in the selected Pcpj mode according to the form ole:

Where
n is the number of engines;
i is the engine number;
j is the selected mode;
Pij - parameter value of the i-th engine in the j-th mode;
then calculate the unbiased dispersion of the selected parameter in the selected mode Sj ² according to the formula:

then check the correspondence of the empirical distribution of the parameter to the normal distribution law, for which the selected asymmetry coefficient A is calculated in accordance with the formula:

and a sample kurtosis coefficient E in accordance with the formula:

as well as the quantities dA, dE, characterizing the correspondence of the empirical distribution of the engine parameter to the normal distribution law:
dA = 3 * Sa- | A |,
dE = 5 * Se- | E |,
where Sa, Se are the standard deviations of the asymmetry and excess, determined by the formulas:

then verify compliance with the inequalities dA> 0, dE> 0 and
Pcpj-2.5 * Sj <Pij <Pcpj + 2.5 * Sj,
in this case, if the above inequalities are observed, the empirical distribution of the values of the selected parameter P in the selected mode j is considered normal, and production is stable, and if the above inequalities are not observed, the production technology, assembly and testing of the engine for deviations are checked, the cause of the discrepancy is identified and eliminated, and repeated evaluate the stability of production in this way.