Sample Calculations
Reynolds and Capillary Numbers
If a 70-micron diameter emulsion containing inner drops moves through a continuous fluid in a glass microfluidic device with a speed of 0.0036 m/s, would the flow around the emulsion be classified as low, moderate or high Reynolds number flow? What is the capillary number? The continuous fluid has a density of 1005 kg/m3 and a viscosity of 20 mPa s.
Drag Force
What is the drag force the emulsion described above experiences while traveling in the channel of a microfluidic device? How does this compare to the drag force that a baseball experiences when traveling at 95 mph in open air?