- Identification: A2060804 - Grant Agency of the Academy of Sciences of the Czech Republic
- Duration: 1998 - 2000
- Principal investigator: Ing. Jiří Myška CSc.
- Co-investigator: RNDr. Petr Štěpánek CSc. (Institute of Macromolecular Chemistry ASCR)
It was proved that the most suitable means of energy saving in district heating and cooling systems is the utilization of the drag reduction phenomenon. Large friction reduction in pipes is achieved by cationic surfactants, which possess important properties like the efficiency at high and low temperatures, and the so called "repairable degradation". Their efficiency can be even larger than that of high polymers. For a better and easier use in heating systems, we have proposed the development of a new surfactant to the producer in the USA. The hydraulic measurements of this surfactant and the investigation of its turbulence and flow characteristics will be made. We shall study mainly the drag reduction in the tube, velocity field and its development behind a singularity, velocity fluctuations, energy spectrum. Rheological behavior of cationic drag reducing surfactants is generally described by a typical feature - Shear Induced Structure (SIS). We have shown that this property can be subdued. The aim of our investigation is what conditions limit the existence of SIS.
