Tejaswi Josyula

Ph.D. Student

Tejaswi Josyula is a Ph.D. candidate working under the guidance of Dr. Arvind Pattamatta and Dr. Pallab Sinha Mahapatra. He is working in the area of sessile droplet evaporation. He has completed B.Tech in Mechanical Engineering from RGUKT-Nuzvid in 2014 and M.Tech in Thermal Engineering from National Institute of Technology Hamirpur in 2016. His research interest also includes multiphase flow, computation fluid dynamics, and experimental techniques of thermal imaging, particle image velocimetry.

Research Topic:

Figure. Evolution of drop shape (top) and temperature at the liquid-vapor interface in evaporating drops on a hydrophilic substrate maintained at (a) 40 oC and (b) 80 oC.

Evaporation of sessile droplets is a ubiquitous phenomenon observed in many natural processes. It is of fundamental and practical importance in applications such as ink-jet printing, spray cooling, biological and chemical assays, medical diagnostics, etc.  With a surrounding atmosphere which is unsaturated with the evaporating liquid, the volume of drop decreases due to evaporation. Fundamental mechanisms involved in this process are heat conduction, convective flows, interfacial tension, surface wettability, and evaporative cooling. Most of our work is focussed on identifying universal features of evaporation and correlate the three critical aspects of sessile droplet evaporation, namely, contact line dynamics, thermal field, and internal flow field. The experimental techniques that are used are optical imaging, thermal imaging, and particle image velocimetry.

 

Figure. (a) Schematic of the formation of a thin laser sheet. Streak line image and velocity vectors inside an evaporating (b) sessile drop and (c) inverted sessile drop. The units of velocity are micrometer/s.

Publications

Journals

[1] Josyula. T, Wang, Z., Askounis, A., Orejon, D., Harish, S., Takata, Y., Mahapatra, P. S., and Pattamatta, A. (2018). Evaporation kinetics of pure water drops: Thermal patterns, Marangoni flow, and interfacial temperature difference. Physical Review E, 98 (5) : 052804.

[2] Josyula. T, Singh. S, Dhiman. P. (2018). Numerical investigation of a solar air heater comprising longitudinally finned absorber plate and thermal energy storage system, Journal of Renewable and Sustainable Energy,  10, 055901.

Conference

[1] Tejaswi Josyula, Pallab Sinha Mahapatra and A. Pattamatta, “Influence of ambient relative humidity on contact line dynamics and interfacial temperature difference in evaporating pure water drops”, Proceedings of the 25th National and 3rd International ISHMT-ASTFE Heat and Mass Transfer Conference (IHMTC-2019), December 28-31, 2019, IIT Roorkee, Roorkee, India.

[2] Tejaswi Josyula, Chandan Manghnani, Pallab Sinha Mahapatra and A. Pattamatta, ”Thermal Patterns and Internal Flow Mechanisms in Evaporating Inverted Sessile Drops of Pure Water”, International Mechanical Engineering Congress and Exposition (IMECE), Calvin L. Rampton Salt Palace Convention Center, Salt Lake City, Utah, November 11 – 14, 2019.

[3] Tejaswi Josyula, Pallab Sinha Mahapatra and A. Pattamatta, ”Effect of Substrate Temperature and Initial Drop Volume on Interfacial Temperature Difference in Evaporating Pure Water Drop”, Proceedings of the 7th International and 45th National Conference on Fluid Mechanics and Fluid Power (FMFP), December 10-12, 2018, IIT Bombay, Mumbai, India.

[4] Tejaswi Josyula, A. Pattamatta and Pallab Sinha Mahapatra, “Evaporation characteristics of a sessile nanofluid droplet on heated substrates with varying wettability”, Proceedings of the 24th National and 2nd International ISHMT-ASTFE Heat and Mass Transfer Conference (IHMTC-2017), December 27-30, 2017, BITS Pilani, Hyderabad, India.

Contact:

Researchgate: https://www.researchgate.net/profile/Tejaswi_Josyula

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