TURBULENCE GENERATION TO CONTROL MUSSEL SETTLEMENT IN HYDROPOWER FACILITY PIPING SYSTEMS

摘要

Intense turbulence in pipe flow may be beneficial in reducing colonization of invasive quagga and zebra mussels within piping systems. These invasive mussels often settle in hydropower piping systems, impacting domestic and cooling water supplies to the facility. While many potentially effective treatments are being developed to prevent mussel colonization, they are often expensive and high-maintenance. A new treatment method that generates intense turbulence in the pipe flow is currently being researched. The intent of this method is to physically damage juveniles (veligers) near the system intake to prevent them from colonizing within piping downstream. If effective, this treatment could potentially be applied as a retrofit to piping systems in existing hydropower facilities that is relatively cost-effective and low-maintenance. Preliminary results of the turbulence treatment have been obtained from both laboratory and field testing. Particle Image Velocimetry (PIV) was used in the laboratory to quantify hydrodynamic properties of the pipe flow field affected by the turbulence generation. Results showed that the flow field was significantly altered compared to regular pipe flow and that the increased turbulence levels were within the range expected to impact invasive mussels. This method was then tested at Reclamation’s Davis Dam hydropower facility to determine effects to live veligers. Currently only preliminary results are available. Mussel settlement testing is not yet concluded. Images from Reclamation’s FlowCAM? system showed that acute physical damage of treated veligers is possible from the turbulence. A direct comparison of mussel mortality and settlement with hydrodynamic data will be very valuable in the future development of this treatment which could potentially be a great benefit to a variety of hydropower and water resource facilities.