Zhizhao Che

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In this paper, thermal mixing characteristics of two miscible fluids in a T-shaped microchannel are investigated theoretically, experimentally, and numerically. Thermal mixing processes in a T-shaped microchannel are divided into two zones, consisting of a T-junction and a mixing channel. An analytical two-dimensional model was first built to describe the(More)
The impact of droplets on an inclined falling liquid film is studied experimentally using high-speed imaging. The falling film is created on a flat substrate with controllable thicknesses and flow rates. Droplets with different sizes and speeds are used to study the impact process under various Ohnesorge and Weber numbers, and film Reynolds numbers. A(More)
The impact of droplets on liquid films is ubiquitous in natural and industrial processes, and surfactants can significantly alter the impact process by changing the local surface tension. Here we study the impact of droplets on liquid films in the presence of surfactant using high-speed photography, and reveal the flow pattern by dye-tracing. The effects of(More)
Idris Adebayo,1 Zhihua Xie,1,2 Zhizhao Che,1,3 and Omar K. Matar1 1Department of Chemical Engineering, Imperial College London, SW7 2AZ, United Kingdom 2School of Engineering, Cardiff University, Cardiff, CF24 3AA, United Kingdom 3State Key Laboratory of Engines, Tianjin University, Tianjin, People’s Republic of China (Received 27 February 2017; revised(More)
Droplets moving in meandering microchannels can serve as a passive and robust strategy to produce chaotic mixing of species in droplet-based microfluidics. In this paper, a simplified theoretical model is proposed for plug-shaped droplets moving in meandering microchannels at Stokes flow. With this model to provide the velocity field, particle tracking,(More)
Surface nanobubbles are stable gaseous phases in liquids that form on solid substrates. While their existence has been confirmed, there are many open questions related to their formation and dissolution processes along with their structures and properties, which are difficult to investigate experimentally. To address these issues, we carried out molecular(More)
A simple method for evaluating chaotic advection in slug micromixing is reported in this paper. We consider a slug moving in a slit microchannel (w>> h) and flow field in a plane far from the boundary walls is modelled as a two-dimensional low-Reynolds-number flow (Stokes flow). Analytical solution for normalised velocity field in the slug is derived. The(More)
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