Tow and wave tank

Our tow/wave tank, located at the Jere A. Chase Ocean Engineering Laboratory, was constructed in 1996, and its linear motion, control, and data aquisition systems were redesigned and renovated in 2012.

The tank is also home to our turbine test bed.

Specifications summary

Linear motion and control

Along the length of the tank are two 1.25 inch diameter 440C stainless steel linear shafts, guiding the motion of the main tow and YZ traversing carriages. The carriage motion is actuated by a permanent magnet servo motor, driving an ATL20 timing belt. Servo drives for the carriage, turbine test bed, and YZ traverse motors are all controlled by an EtherCAT master real time controller, providing precise synchronization between all components.

Data acquisition and on-board accessories

The data acquisition (DAQ) system is based around a Natioal Instruments 9188 CompactDAQ Ethernet chassis. Various modules are available for sampling analog voltage, bridge-based measurements, and digital measurements, including sampling carriage position from the 10 μm resolution linear encoder.

Data collection from motion control devices is also possible through the main motion controller, and from up to 8 serial devices simultaneously.

There is enough AC power available on board the carriage to operate a high frame rate particle image velocimetry (HFR-PIV) system. An additional servo drive on the carriage is used to provide precise control of turbine RPM when operating the turbine test bed. There is also a 2-axis stepper drive, mainly used to control the y- and z-location of a Nortek Vectrino acoustic Doppler velocimeter (ADV).