Digital Measuring Devices Used for Injector Hydraulic Test

Nauka i Obrazovanie

S. N. Leontiev¹  D. M. Yagodnikov¹  A. O. Novikov¹ 

[1] Bauman Moscow State Technical University;

关键词: injector;    liquid spraying;    liquid flow rate;    liquid flow rate along spraying cone determination;    spraying cone angle;   

DOI  :  10.7463/1015.0813334

来源: DOAJ

【 摘 要 】

To ensure a high specific impulse of the LRE (liquid-propellant engine) chamber it is necessary to have optimally organized combustion of the fuel components. This can be ensured by choosing the optimum geometry of gas-dynamic contour of the LRE combustor, as well as by improving the sputtering processes and mixing the fuel components, for example, by selection of the optimum type, characteristics, and location of injectors on the mixing unit of the chamber.

These particular reasons arise the interest in the injector characteristics in terms of science, and technological aspects determine the need for control of underlying design parameters in their manufacture.

The objective of this work is to give an experimental justification on used digital measurement instrumentation and research the hydraulic characteristics of injectors.

To determine injector parameters most widely were used the units with sectional collectors. A technique to control injector parameters using the sectional collectors involves spraying the liquid by injector at a given pressure drop on it for a certain time (the longer, the higher the accuracy and reliability of the results) and then determining the amount of liquid in each section to calculate the required parameters of injector.

In this work the liquid flow through the injector was determined by high-precision flowmeters FLONET FN2024.1 of electromagnetic type, which have very high metrological characteristics, in particular a flow rate error does not exceed 0.5% in a range of water flow from Qmin= 0.0028 l/s to Qmax Qmax = 0.28 l/s. To determine the coefficient of uneven spray were used differential pressure sensors DMD 331-ASLX of company "DB Sensors RUS", which have an error of 0.075% with a range of differential pressure 0 ... 5 kPa. Measuring complex MIC-200 of company "NPP Measure" and WinPos software for processing array information provided entry, recording, and processing of all the data of the experiment.

In this paper the following conclusions are drawn:

1. The use of digital sensors enabled increasing accuracy of the flow rate up to 0.5%, and the error in determining the coefficient Кn ~ 0.5%.

2. For the first time in practice we proposed and implemented a method for determining the coefficient of spraying unevenness from the difference in the rate of rise of the excess hydrostatic liquid pressure in each section of collector depending on the collection time of the injector.

3. Using a current value of raising overpressure gradient in each section, it is possible to provide a continuous control of the injector parameters that has practical implication for the study of the LRE control process.

【 授权许可】

Unknown