SIMULTANEOUS INSITU MEASUREMENTS OF SIZE AND VELOCITY OF BURNING DROPLETS

被引：13
作者：
ANDERS, K
ROTH, N
FROHN, A
机构：
[1] Itlr Institut Für Thermodynamik Der Luft- Und Raumfahrt, Universität Stuttgart, Stuttgart, 7000
来源：
PARTICLE & PARTICLE SYSTEMS CHARACTERIZATION | 1991年 / 8卷 / 02期
关键词：
D O I：
10.1002/ppsc.19910080125
中图分类号：
O64 [物理化学（理论化学）、化学物理学];
学科分类号：
070304 ; 081704 ;
摘要：
An optical instrument for simultaneous on-line measurements of the droplet size and droplet velocity of periodically generated droplets is described. This instrument is suitable for studying basic phenomena such as the evaporation or combustion of small droplets and the mutual interaction of neighbouring droplets. For the study of evaporation and combustion rates it is important to have precisely defined initial and boundary conditions. A vibrating-orifice generator is used to produce monodisperse droplet streams which are characterized by their highly coherent structure. The droplets all have the same size, the same spacing and the same initial velocity. These characteristic parameters of the droplet stream can be adjusted over a wide range as required for the specific experiment. The droplet size is measured with a sizing method of very high accuracy, which evaluates the intensity distribution of the light scattered by the droplets. The droplet diameter ranges from 10 to 150-mu-m. The droplet velocity is measured by a particle image displacement velocimeter and is compared with conventional LDV measurements. The results of the two methods agree very well. Typical droplet velocities lie in the range from 10 to 20 m/s. Some exemplary experimental results are presented for burning droplet streams, which show the influence of a finite spacing between the droplets on the burning rate.
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页码：136 / 141
页数：6
相关论文
共 8 条
  • [1] Anders K., Frohn A., Experimental Investigation of Droplet Evaporation in a Wide Knudsen Number Range, Proc. 14th Int. Symp. Rarefied Gas Dynamics, pp. 975-982, (1984)
  • [2] Anders K., Roth N., Frohn A., Study of the Evaporation and Combustion of Droplets by a New Optical Sizing Method, Proc. 6th Int. Congr. on Applications of Lasers and Electro‐Optics, 63, pp. 205-214, (1987)
  • [3] Brenn G., Frohn A., Collision and Merging of Two Equal Droplets of Propanol, Experiments in Fluids, 7, pp. 441-446, (1989)
  • [4] Berglund R.N., Liu B.Y.H., Generation of Monodisperse Aerosol Standards, Environ. Sci. Technol., 7, pp. 147-153, (1973)
  • [5] Konig G., Anders K., Frohn A., A New Light Scattering Technique to Measure the Size of Periodically Generated Moving Particles, J. Aerosol Sci., 17, pp. 157-167, (1986)
  • [6] Lourenco L., Krothapalli A., The Role of Photographic Parameters in Laser Speckle or Particle Image Displacement Velocietry, Experiments in Fluids, 5, pp. 29-32, (1987)
  • [7] Francon M., Interferences, Diffraction et Polarisation, Handbuch der Physik, 24, pp. 292-296, (1956)
  • [8] Lui D.Y., Anders K., Frohn A., Drag Coefficients of Single Droplets Moving in an Infinite Droplet Chain on the Axis of a Tube, International Journal of Multiphase Flow, 14, pp. 217-232, (1988)
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