An aqueous suspension of 1% by weight laponite was investigated in terms of its rheology and hydrodynamic behaviour in a sudden expansion flow. The fluid was shear-thinning, thixotropic and had an yield stress which was measured by direct and indirect methods. The oscillatory tests showed that the elasticity of the 1% Laponite suspension was very small.
The high Reynolds number turbulent flow downstream of a sudden expansion, with fully-developed inlet conditions, showed no major difference in relation to the flow of water. There were no differences between the laponite and water mean and turbulent flow characteristics upstream and downstream of the expansion plane, except for a small anticipation of the loci of maximum Reynolds stresses with the suspension, but this had no further consequence.
In conclusion, although the laponite suspension was thixotropic, shear-thinning and viscoplastic, its hydrodynamic behaviour in a sudden expansion was akin to that of water, a result which could not be anticipated.