Source: E-USOC

The current experiment set-up consists of a 10cm square transparent acrylic container, manufactured to hold a 2-5cm deep layer of fluid. We use both silicone oil (DC 200) and water. A sharp step pins the contact line when desired.

The container is mounted on a specially constructed dual rail system and is free to slide horizontally in response to the forcing delivered by a VTS-150 electromagnetic shaker. The motion is monitored with an accelerometer (ADXL321) mounted directly on the wall of the container.

A system of lenses and mirrors provides illumination through the (transparent) bottom of container, and the resulting image is captured, via a shadowgraphy-type technique, with a high speed camera (Redlake MotionPro X3). The experiments rests on a 2m x 1.25m (Thorlabs) optical table with passive vibration isolation supports, and is controlled via a computer equipped with LabView software.

In the past year we have added an infrared LASER (HSI 5000) and are refining our capacity to make PIV measurements of the interior. This will enable us to quantitatively measure the extent and influence of both the viscous mean flow and the oscillating bulk flow, which is the driving forcing behind the subharmonic instability.