Hydrodynamic flow and micromixing

Which of the following best defines hydrodynamic flow?

• The study of fluids at rest.

• The study of gases in motion.

• The study of fluids in motion.

• The study of solids in motion.

The type of flow in which fluid particles move along straight parallel paths is known as:

• Steady flow

• Laminar flow

• Turbulent flow

• Compressible flow

Which of these factors do NOT directly influence hydrodynamic flow?

• Fluid viscosity

• Fluid velocity

• The color of the fluid

• Surface area

Which of the following is a real-world application of hydrodynamic flow?

• Predicting weather patterns in meteorology

• Designing aerofoil shapes in aerospace engineering

• Designing water treatment systems

• All of the above

Which of the following methods is commonly used to enhance mixing in microchannels?

• Increasing fluid viscosity

• Reducing channel size
  

• Creating a chaotic flow using obstacles or patterns in the channel

• Increasing the length of the channel

The Peclet number in a microchannel is a measure of which of the following?

• The ratio of diffusive to convective transport

• The strength of secondary flows induced by curvature

• The frequency of flow disturbances caused by obstacles

• The balance between centrifugal and viscous forces

What is the main advantage of serpentine microchannels compared to straight ones in terms of mixing?

• They increase the surface area available for diffusion

• They reduce the Peclet number, thus enhancing diffusion

• They induce secondary Dean vortices due to the curved flow path, which can enhance mixing

• They reduce the fluid velocity, thus enhancing diffusion

In an obstacle-embedded microchannel, what does a higher Strouhal number generally indicate?

• Higher fluid velocity

• Higher frequency of flow disturbance, potentially enhancing mixing

• Lower diffusivity of the fluid

• Lower fluid viscosity