Experimental Study of the Laser Induced Flow and Thermophoresis in Suspending Microparticles

The induced flow effect is the rotary motion generated in the fluid flow due to the temperature gradient. The phenomenon of thermophoresis is the movement of particles from the warmer side of the fluid to the cooler side. Laser is a very suitable device for creating a temperature gradient due to its unique features such as high power density, harmonic waves, single wavelength and very low divergence. Thermophoresis phenomenon and induced flow have many uses in the transfer of particles and in various fields such as medicine and industry. In the present work, the phenomena of laser thermal interactions and flows of microparticles were studied. Thermophoresis phenomenon and induced flow were investigated experimentally using laser. Scale analysis of the migration velocity caused by the laser thermal effects shows that the induced flow in the fluid has a larger scale in comparison with the thermophoresis phenomenon. Thus, the focus of the experimental study was on the laser induced flow by the local heat absorption of Rhodamine B solutions. Review of recent researches show that the idea of Rhodamine B topical absorption to create fluid motion has not been previously published. Therefore, it is considered as the most important novelty of the present work.