Current Research Focus:
Theoretical pore scale fluid physics
- Multiphase flow through rock fractures
Effect of surface roughness on flow
- "Pet Physics" Animals interacting with fluids
- Physics Education Research, improving assessment in introductory
A new field in fluid physics is emerging from a curiosity about
how the natural world works. This application of fluid physics is being
called “Pet Physics” by the media and seeks to answer
questions about how animals interact with fluids. These investigations
include “cat lapping” and the “wet dog shake.”
I use a high-speed camera to capture the fast dynamics of animals
interacting with fluids, including the lapping of domestic cats and
Sumatran tigers at Point Defiance Zoo and Aquarium. Then I model this
interaction experimentally and theoretically. The purpose of pet
physics is to better understand how nature works and to apply the most
successful concepts to improve current inventions. Animals have adapted
to their environments and evolved to use the most efficient methods;
industry will do well to imitate many natural processes already known
intuitively by animals.
Rock Fracture Project:
The overall goal of our project is to
explain fluid transport from the surface to the ground water. This has
and environmental applications, everything from nuclear contaminant
flow to pesticides to silver extraction.
Before one can model the big picture
of multiphase flow in a rock fracture system it is important to
understand the basic physics that describes types of fluid movement and
interaction with boundaries. In a fractured rock system, the rock
surface can be porous, moist, chemically heterogeneous and rough.
Focusing on roughness, specific projects include the creation of a
theoretical model for the wetting of a rough surface.
laws based on capillarity and fluid and surface frictional resistive
forces are used to predict fluid invasion rates.
This project also includes experimental investigations into multiphase flow
in fractured rock
systems. These investigations focus on the effect
of surface roughness on fluid droplets (or "liquid bridges"). The
fluid-solid contact angle is important in the dynamics as it effects
the extent of interface curvature and therefore the capillary pressure
gradient across the droplet. This gradient can resist or assist
the downward droplet motion. We found that the speed of droplets
moving down glass fractures is significantly different than the speed
down rock fractures. Experiments are being used to develop predictive
calculate the speed of liquid droplets in unsaturated rock fractures.
The study of fluid physics is important for understanding
many fluid processes. Many processes in nature can be described by
fluid dynamics, including glacier movement, galaxy rotation, ocean
currents, atmospheric dynamics, water ingestion of animals and
microscopic pore filling in soils and rock.