Geocentrifuge Research Laboratory
About the Geocentrifuge Research Facility
There are fewer than 25 geocentrifuges (also known as geotechnical centrifuges) larger than 2 meters in the United States. Most of these facilities specialize in geotechnical testing, earthquake analysis, and physical testing of large mechanical and civil engineering objects. The INL Geocentrifuge Research Facility is being used to improve mathematical models for the movement of fluids and contaminants and long-term performance of engineered caps and barriers used for subsurface waste disposal or stabilization, and for nuclear- and national defense-related research. The INL Geocentrifuge Research Facility consists of a 2-meter geotechnical centrifuge, an experimental package preparation area, control room, an electronic lab and office space for data analysis.
The Geocentrifuge Research Laboratory is located in north Idaho Falls, Idaho adjacent to the INL Research Center (IRC). The leased space for the facility is located in the Bonneville County Technology Center. Conference rooms and a receptionist are shared by all building tenants and are included in the lease. The Geocentrifuge Research Laboratory consists of a high bay area for the geocentrifuge and a separate space that includes three offices and a control room.
Geocentrifuge Research Facility
The Geocentrifuge Research Facility consists of a high-bay laboratory for the geocentrifuge and a separate space that includes three offices and a control room. The 287-m 2-geocentrifuge laboratory consists of 21.5 x 9.1-m high-bay engineering space and 10.2 x 8.8-m laboratory space for electronic/instrumentation support, control room and offices. Part of the high-bay space houses the geocentrifuge in a 5.6-m removable steel-walled concrete chamber. The remaining high-bay space (120 m 2) is used to prepare models and store soils.
The laboratory/office space is configured with removable partitions to provide the geocentrifuge control room, office space for three people, and electronics/instrumentation support for configuring and testing sensors for use in centrifuge models. Extensive chemistry, physics, microbiology, and instrument laboratories are available in the INL Research Center.
INL purchased the computer-controlled 2-meter-radius, 50 g-tons Model C61-3 geocentrifuge from Actidyn Systemes. The specifications for the geocentrifuge are shown at right.
The geocentrifuge has an asymmetric beam equipped with a pendulum swinging basket that rotates in a cylindrical steel-and-concrete enclosure, which offers both centrifuge safety and aerodynamic efficiency during operation.
One significant feature of the geocentrifuge is an automatic balancing system. Because many environmental geocentrifuge applications may require fluid movement, this could lead to a change in the center of mass of the sample chamber. Our geocentrifuge will automatically compensate for such shifts during operation.
|Centrifuge Specifications |
||10 to 130 g|
||11 to 145 g|
||51 to 262|
|Mass at 100 g
|Mass at 130 g
|Electrical Slip Rings
||Liquid to Air
Control and data acquisition system
A stand-alone operator’s computer, located in the control room, provides fully automated operation of the geocentrifuge. Because many environmental centrifuge applications may require hundreds of hours of centrifuge time, the geocentrifuge is configured to be operated continuously and remotely from a control room. A qualified operator will monitor geocentrifuge operations at all times. Geocentrifuge functions can also be monitored via the Internet from remote locations.
The data acquisition system employs a fiber-optic rotary joint with a 100-MHz transmission rate, which links the computer at the center of the centrifuge arm with the user’s computer in the control room. Using the fiber-optic rotary joint and the on-arm computer avoids transmitting analog data signals through slip rings, which eliminates the noise associated with electrical slip rings. The expandable on-arm computer allows control for in-flight experimental manipulations. As with the operator’s computer, the user’s computer will be configured to allow remote Internet monitoring and control of experimental and data collection functions.
INL thanks the Bechtel Corporation’s Corporate Funded Research and Development program for providing the support to develop the geocentrifuge facility. We also thank Jacques Perdriat of Actidyn Systemes for his technical assistance.