112. An improved size and refractive index measurement of a pentadecane single droplet in a heated chamber

W. Manosroi1, N. Roth2, B. Weigand3

1, 2, 3Institute of Aerospace Thermodynamics, University of Stuttgart, Pfaffenwaldring 31, 70569, Germany

1Department of Mechanical Engineering, Chiang Mai University, Chiang Mai 50200, Thailand

1Corresponding author

E-mail: 1woradej.manosroi@gmail.com, 2norbert.roth@itlr.uni-stuttgart.de, 3bernhard.weigand@itlr.uni‑stuttgart.de

Received 2 February 2017; received in revised form 18 February 2017; accepted 23 February 2017

DOI https://doi.org/10.21595/jme.2017.18225


Abstract. The pentadecane single droplet size of less than 20 µm and its refractive index were measured at various ambient temperatures of 100, 120, 150 and 180 °C. The experimental setup was equipped with the high speed linear CCD camera to give sharp and clearly visible MDRs (Morphology Dependent Resonances) structure from the droplet refractive index. The valve of the heated chamber was closed during the experiment until the droplet disappeared from the chamber to increase the measurement time of about 2 folds in order to obtain more experimental data of the droplet behaviors. The cooling device was mounted on the heated chamber to improve boundary condition and smooth the ambient temperature. The obtained droplet sizes were in good agreement with both the D2 law and the Rapid Mixing Model (RMM), while the measured droplet refractive index values were closed to those calculated from the previous reported formula. This has indicated the reliability and applicability of this improved measurement technique for a better understanding of the real fuel droplet behaviors in a combustion system.

Keywords: droplet, ambient temperatures, diameter, refractive index, morphology dependent resonances.


[1]        Wilms J. Evaporation of Multi-Component Droplets. Ph.D. Thesis, Universität Stuttgart, Verlag Dr. Hut, 2005.

[2]        Glover A. R., Skippon S. M., Boyle R. D. Interferometric laser imaging for droplet sizing: a method for droplet-size measurement in sparse spray systems. Applied Optics, Vol. 34, Issue 36, 1995, p. 8409‑8421.

[3]        Castanet G., Delconte A., Lemoine F., Mees L., Grehan G. Evaluation of temperature gradients within combusting droplets in linear stream using two colors laser induced fluorescence. Experiments in Fluids, Vol. 39, 2005, p. 431‑440.

[4]        Castanet G., Lemoine F. Heat transfer within combusting droplets. Combustion Institute, Vol. 31, 2007, p. 2141‑2148.

[5]        Roth N., Anders K., Frohn A. Simultaneous measurement of temperature and size of droplets in the micrometric range. Journal of Laser Applications, Vol. 2, 1990, p. 37‑42.

[6]        Roth N., Anders K., Frohn A. Refractive index measurements for the correction particle sizing methods. Applied Optics, Vol. 30, Issue 33, 1991, p. 4960‑4965.

[7]        Anders K., Roth N., Frohn A. Influence of Refractive Index Gradients within Droplets on Rainbow Position and Implications for Rainbow Refractometry. Particle & Particle Systems Characterization, Vol. 13, 1996, p. 125‑129.

[8]        Kobayashi T., Kawaguchi T., Maeda M. Measurement of Spray Flow by an Improved Interferometric Laser Imaging Droplet Sizing (ILIDS) System. Department of System Design Engineering, Japan, 2000.

[9]        Kawaguchi T., Akasaka Y., Maeda M. Size Measurements of Droplets and Bubbles by Advanced Interferometric Laser Imaging Technique. Department of System Design Engineering. Keio University, Japan, 2002.

[10]     Fieberg C., Reichelt L., Martin D., Renz U., Kneer R. Experimental and Numerical Investigation of Droplet Evaporation under Diesel Engine Conditions. International Journal of Heat and Mass Transfer, Vol. 52, 2009, p. 3738‑3746.

[11]     Sangkaew S. Development of Novel Global Rainbow Technique for Characterizing Spray Generated by Ultrasonic Nozzle. Doctoral Thesis, Chulalongkorn University, Thailand, 2005.

[12]     Fandrey C., Isvik S., Naqwi A., Shakal J. Dual beam rainbow refractometry and its application to the temperature measurement of liquid drops. http://in3.dem.ist.utl.pt/downloads/lxlaser2000

[13]     Honnery D., Nguyen D., Soria J. Microdroplet evaporation under increasing temperature conditions: experiments and modeling. Fuel, Vol. 105, 2013, p. 247‑257.

[14]     Hiroyasu H., Kadota T. Fuel droplet size distribution in combustion chamber. Bulletin of JSME, Vol. 19, Issue 135, 1976, p. 740715.

Cite this article

Manosroi W., Roth N., Weigand B. An improved size and refractive index measurement of a pentadecane single droplet in a heated chamber. Journal of Measurements in Engineering, Vol. 5, Issue 1, 2017, p. 1‑10.


Journal of Measurements in Engineering. March 2017, Volume 5, Issue 1

© JVE International Ltd. ISSN Print 2335-2124, ISSN Online 2424-4635, Kaunas, Lithuania