Computational fluid dynamics

With modern-day computers and several open-source CFD packages, it is today quite straightforward to simulate Newtonian flows.

Adding even a small amount of dissolved polymer into a fluid can have a dramatic impact on the way it flows. If the flow is turbulent (high-Reynolds-number) to begin with, then the polymer can strongly modify the turbulent eddies and reduce the drag force (in flow through pipes) or even make the flow laminar. Known as the Toms effect, this phenomena is exploited to reduce the pumping costs associated with transporting oil in pipelines. Polymers can also destabilize a low-Reynolds-number steady flow and make it unsteady and chaotic.

Particle size reduction is a highly energy intensive operation and even small improvements in efficiency can result in significant energy savings. The focus of the present work is analysis and optimization of an air jet mill, which is a versatile equipment used in many industries for fine grinding of powders to sizes less than around 10 microns. The objective of the project is be to develop a detailed simulation model using computational fluid dynamics (CFD) and the discrete element method (DEM).

Microfluidics technology has been seen to have great potential in lab-on-a-chip applications including chemical analysis and diagnostics. However, flow control in these networks requires either a pneumatic or fluidic control layer over the microfluidic layer. Recent studies have shown that integrated flow control may be achieved by introducing capacitive elements or obstacles in the flow path so that system response becomes non-linear as required for flow switching.