System of the laser measurements by particulate composition for two-phase flows

Propulsion and Power Plants


Аuthors

Zuyev Y. V.1*, Istomin Е. А.2**, Lepeshinskii I. A.1***, Reshetnikov V. A.1****, Chabanov V. A.3*****

1. Moscow Aviation Institute (National Research University), 4, Volokolamskoe shosse, Moscow, А-80, GSP-3, 125993, Russia
2. Scientific production enterprise «Temp» named after F.Korotkova, 23, Pravdy str., Moscow, 127015, Russia
3. State Institute of Aviation Systems, 7, Victorenko str., Moscow, 125319, Russia

*e-mail: yuri_zuev@bk.ru
**e-mail: eistomin@inbox.ru
***e-mail: igorlepesh@yandex.ru
****e-mail: vresh031152@mail.ru
*****e-mail: infocenter@gosnias.ru

Abstract

Issues related to measurement of particle size distribution of two-phase flow in the mixing devices of the combustion chambers of the air-jet engine by laser-optical methods are considered. Special attention is paid to the solution of problems that arise when a large distance to the measuring volume and polydispersed composition of the liquid phase. This is due to the fact that when working with real fuels, such as kerosene, it is necessary measuring equipment to remove possible distance, and the droplet size of the fuel in the combustion chambers, as a rule, vary widely. The block diagram and design of a laser measurement system are considered.

In the operation of the ring photodetectors, which are typically used in laser measuring sizes of particles, is replaced by a matrix of a digital camera. This allows you to create a system where the laser and reception optics do not have a rigid connection which is important in conditions of full-scale experiment. In this case center of diffraction pattern of each frame is set programmatically. The multiple times photographic registration of two-phase flow following by a specially designed procedure «stitching» frames is used to increase the dynamic range of the measurements . Also to improve the measurement accuracy characteristic curve of the matrix a digital camera is based, by which means is determined by the intensity registered by the matrix of light. It is shown that the using installed in the focal plane of the Fourier lens the additional light-diffusing screen allows you to extend the range of the measured particle size and to simplify the optical system of registration. In this case telephoto Fourier lens of large diameter were used to work at greater distances (in our experiments we used a lens with a focal length of 500 mm light diameter of 195 mm). A light-diffusing screen was made from sandblasted on one side of the glass by thickness of 3 mm and size 300 mm.

The block diagram and design system, laser measurement of dispersion of two-phase flows, which was used in full-scale tests are considered To improve the reliability of the measurements and to expend a measuring range, the emitter unit contains two laser emitters — red (wavelength 650 nm, type KLM-650/20) and green (532 nm, KLM 532-30-5). Depending on the set before the experimenter tasks possibly using different algorithms for processing the received scattering indicatrixes.

To assess the validity of the results obtained by using the system of laser measurements of particle size, comparative experiments with analyzer of particle size the firm Malvern were carried out The distance to the test object of research the analyzer Malvern was 4 times less. The comparison showed that the differences do not exceed 8%.

Also the results obtained in the experimental study of the mixer on a working body air-water with the formation of gas-droplet stream are presented. It was found that the investigated mixer with increasing gas flow rate at constant liquid flow rate Sauter mean diameter of the droplets is reduced from 140 to 90 ?m. At a constant concentration of the liquid phase and the increase of flow rate from 1.5 to 2.25 kg/s, there is a minimum in diameter which is in the area of consumption of 2 kg/s.

Keywords:

combustion chamber, a mixing device, a two-phase flows, the particle size distribution, droplet size of the fuel, laser-optical methods of measuring particle sizw, small-angle scattering

References

  1. Lazernyi difraktsionnyi analizator chastits Analesette 22 Nanotech. Tsentr kollektivnogo pol'zovaniya nauchnym oborudovaniem, available at: http://www.ckp-bsu.ru/ lazernyi-difraktcionnyj-analizator-razmera-chastic- analizette-22-nanotech, 2009.
  2. Lazernyi analizator Horiba LA-950, available at: http:/ /rvs-ltd.ru/la9501, 2009.
  3. Lazernyi analizator Partica LA-950, available at: http:/ /www.rvs-ltd.ru/la950, 2007.
  4. Lazernyi analizator razmera chastits Mastersizer 2000 (Malvern), available at: http://www.spectrolab.by/index.pl?act=PRODUCT&id=196, 2009.
  5. Zuev Yu.V., Istomin E.A., Lepeshinskii I.A., Reshetnikov V.A., Chabanov V.A. Materialy X Mezhdunarodnoi konferentsii po neravnovesnym protsessam v soplakh i struyakh «NPNG' 2014», Alushta, 25-31 May 2014, Moscow, MAI, 2014, pp. 93-95.
  6. Dispersnyi sostav aerozolei i smesei. Opredelenie razmerov chastits po difraktsii lazernogo izlucheniya. ISO 13320:2009 (NEQ). GOST R 8.777-2011 (The particle size distribution of aerosols and mixtures. Determination of particle size on diffraction of laser radiation. ISO 13320:2009 (NEQ). State Standart R 8.777-2011), Moscow, Standarty, 2012, 8p.
  7. Van de Khyulst G. Rasseyanie sveta malymi chastitsami (Light scattering by small particles), Moscow, Inostrannaya literatura, 1961, 536 p.
  8. Deirmendzhan D. Rasseyanie elektromagnitnogo izlucheniya sfericheskimi polidispersnymi chastitsami (Electromagnetic scattering on spherical polidispersions), Moscow, Mir, 1971, 168 p.
  9. Boren K., Khafmen D. Pogloshchenie i rasseyanie sveta malymi chastitsami (Absorption and scattering of light by small particles), Moscow, Mir, 1986, 664 p.
  10. Tikhonov A.I., Goncharskii A.V., Stepanov V.V., Yagola A.G. Chislennye metody resheniya nekorrektnykh zadach (Numerical methods for solving ill-posed problems), Moscow, Nauka, 1990, 231 p.
  11. Shifrin K.S. Rasseyanie sveta v mutnoi srede (Light scattering in turbid environment), Moscow-Leningrad, Gostekhteorizdat, 1951, 288 p.
  12. Zimin E.P., Krugerskii A.M. Optika i spektroskopiya, 1979, vol. 46, no. 4, pp. 720-724
  13. Zuev Yu.V., Istomin E.A., Lepeshinskii I.A., Reshetnikov V.A., Chabanov V.A. Materialy X Mezhdunarodnoi konferentsii po neravnovesnym protsessam v soplakh i struyakh «NPNG' 2014», Alushta, 25-31 May 2014, Moscow, MAI, 2014, pp. 96-98
  14. Zuev Yu.V., Lepeshinskii I.A., Reshetnikov V.A., Istomin E.A. Matematicheskoe modelirovanie, 2012, vol. 24, no. 1, pp. 129-142
  15. Zuev Yu.V., Lepeshinskii I.A., Reshetnikov V.A., Istomin E.A. Vestnik MGTU im. N.E. Baumana. Mashinostroenie, 2012, no. 1, pp. 42-54

mai.ru — informational site of MAI

Copyright © 1994-2024 by MAI