Baburaj A.Puthenveettil
Deparment of Applied Mechanics
Indian Institute of Technology Madras
Chennai, India 600036

Jaywant H. Arakeri,
Department of Mechanical Engineering,
Indian Institute of Science
Bangalore, India 560012

Line plumes on a membrane

This striking red image has features that are reminiscent of river valleys or perhaps root system. It actually is the top-down view of sheets of less-dense fluid that are rising from the top of a horizontal permeable membrane that separates heavier brine above lighter water.

The membrane has pores 35 micrometers in size. These sheets of lighter fluid, known as line plumes, form and merge, and then new plumes are initiated in the space vacated by the merger. The initiation of a plume occurs as a blob, seen as isolated points in the relatively vacant regions in the image. These blobs are soon elongated into lines by the velocity field existing around the blob. This is due to the entrainment flow into the line plumes around the blob.

In addition, the external shear due to the flow in the regions far away from the membrane aligns these line plumes, to create a beautiful dendritic structure of these structures near the membrane.

Reporters and Editors

This image can be freely reproduced with the accompanying credit: "Baburaj A. Puthenveettil & Jaywant H. Arakeri (IIT Madras & IISc Bangalore, India)."