Abstract
It is well known that some water-suspension of minerals show a thixotropic characteristics from a viewpoint of rheology. It is usually considered that such rheological properties are due to the inner structure of suspensions. Such an inner structure of suspension may also have some effects on the thermophysical properties, and accordingly, on the heat transfer characteristics. In the present paper, heat transfer characteristics of non-Newtonian suspensions flow over a horizontal heated tube have been investigated experimentally. Water suspensions of mineral powders such as bentonite and attapulgite were employed as a sample fluid. Experimental results showed that the change of shear rate near the wall had some effects on the thermophysical properties of sample fluid, and that not only rheological properties of fluid but also its thermophysical properties near the heat transfer surface may exert considerable effects on the heat transfer characteristics of non-Newtonian fluid.
