Tracking Schooling Fish in Three Dimensions: Experiments at the Rotterdam Zoo

This thesis describes methods and first analyses to study the shape and motion of a large school of approximately 2000 Harengula clupeola (false herring) in three-dimensional space. This school of fish was present at the large-scale and publicly accessible ocean aquarium of the Rotterdam zoo, in the Netherlands known as Diergaarde Blijdorp, from...

Rapid flapping and fibre-reinforced membrane wings are key to high-performance bat flight

Bats fly using significantly different wing motions from other fliers, stemming from the complex interplay of their membrane wings’ motion and structural properties. Biological studies show that many bats fly at Strouhal numbers, the ratio of flapping to flight speed, 50–150% above the range typically associated with optimal locomotion. We use...

The unsteady aerodynamics of insect wings with rotational stroke accelerations, a systematic numerical study

To generate aerodynamic forces required for flight, two-winged insects (Diptera) move their wings back and forth at high wing-beat frequencies. This results in exceptionally high wing-stroke accelerations, and consequently relatively high acceleration-dependent fluid forces. Quasi-steady fluid force models have reasonable success in relating...

Active suspensions in thin films: Nutrient uptake and swimmer motion

A numerical study of swimming particle motion and nutrient transport is conducted for a semidilute to dense suspension in a thin film. The steady squirmer model is used to represent the motion of living cells in suspension with the nutrient uptake by swimming particles modelled using a first-order kinetic equation representing the absorption...

Slow growth of the Rayleigh-Plateau instability in aqueous two phase systems

This paper studies the Rayleigh-Plateau instability for co-flowing immiscible aqueous polymer solutions in a microfluidic channel. Careful vibration-free experiments with controlled actuation of the flow allowed direct measurement of the growth rate of this instability. Experiments for the well-known aqueous two phase system (ATPS, or aqueous...