A high-precision rotating disk apparatus for drag reduction characterization

A high-precision rotating disk apparatus (RDA) simulating "external flow" is designed and then applied to polymer-induced turbulent drag reduction characterization. The need for a sensitive measuring system at high Reynolds numbers has triggered the development of a computer-aided system, which is able to measure the difference between the torques for a Newtonian fluid and a dilute suspension with drag reducer. In addition, because temperature control in this study is more stable than for most other drag reduction measurement equipment, this modified RDA is suitable for measuring the drag reduction under constant temperature condition. (C) 2000 Elsevier Science Ltd. All rights reserved.