Geocentrifuge Research Laboratory
The geocentrifuge subjects a sample to a high-gravity field by spinning it rapidly around a central shaft. In this high-gravity field, processes, such as fluid flow, occur much more rapidly. Using this technique, researchers can study the effects of tens of years of gravity-induced fluid movement in a few days or weeks. When the geocentrifuge is spinning at 260 revolutions per minute, it is capable of applying up to 130 times the force of earth's gravity on an experimental sample. (See about the geocentrifuge research facility the geocentrifuge research facility.)
New flexible moisture content probe design
The geocentrifuge is constructed with an asymmetric beam arm and pendulum swinging basket that rotates within a steel-and-concrete enclosure, which ensures both safety and aerodynamic efficiency during operation. A particularly significant feature of the geocentrifuge is the automatic balancing system. Many environmental geocentrifuge applications involve fluid movement, which could lead to a change in the center of mass of the sample. Our geocentrifuge will automatically compensate for center of mass changes during operation.
INL researchers are using the geocentrifuge to evaluate engineered caps and barriers, develop more effective landfill designs, improve our ability to characterize contaminated sites, and study basic geophysical processes.
Our ongoing research includes: experiments to evaluate contaminant transport in unsaturated materials, multiphase fluid flow in fractures, buoyancy related environmental and national defense research, and colloidal transport research
Experimental setup on the INL geocentrifuge
New tools are being developed to conduct accelerated research experiments in the INL geocentrifuge. These tools need to be capable of collecting information more rapidly than traditional laboratory experiments, and withstand the high centrifugal force while the geocentrifuge is spinning. Tool designs to monitor experiments while they are in flight include new moisture content sensors, modified soil testing columns, fluid sampling apparatus, and a rapid geophysical tomographic data collection system.
Due to the large payload that can be spun, experimental control and monitoring are accomplished by using the onboard computer. This ability allows for greater density of data collection and experimental control of geocentrifuge tests than is capable in smaller centrifuges. Data is transmitted from the geocentrifuge in real time, allowing the researchers to evaluate the results of their experiments while the test is in progress.
In addition, new numerical models have been developed to analyze experimental data from the geocentrifuge. These models include modified versions of HYDRUS 1D and HYDRUS 2D that account for the applied centrifugal force. These models are used for experimental design of geocentrifuge experiments and for parameter estimation from outflow and tracer experiments.
The Geocentrifuge Research Facility is available for use by outside researchers, so scientists from other institutions and laboratories can perform research, and test their scientific and engineering hypotheses. Outside researchers are encouraged to contact INL scientists for collaboration opportunities.