Particle Image Velocimetery (PIV) Diagnostics for Wind Energy and Energy Security Research

Abstract

Particle Image Velocimetery (PIV) is a laser based technique that involves correlation analysis of tracer particle images to estimate the velocity field in a fluid. High resolution velocity measurement capability and non-intrusive nature of PIV make it desirable for understanding complex fluid flow phenomena occurring in various scenarios. This presentation briefly describes the development of novel PIV diagnostics that forward Wind Energy research and advance scaling models to solve expensive maintenance issues of the Strategic Petroleum Reserves (SPR). Two new diagnostic implementations of Particle Image Velocimetry (PIV) are being developed at Los Alamos National Laboratory (LANL) to facilitate understanding of wind turbine aerodynamics in unprecedented detail. It has been demonstrated that a Large-Field PIV (LF-PIV) diagnostic capable of measuring large scale flow fields of up to 4.3m x 2.8m per camera has been developed. This diagnostic, which represents a significant leap in the field of view of existing centimeter scale PIV systems, allows the measurement of velocity fields at multiple points with high accuracy for large scale flows, such as, flows around wind turbines. Further, to characterize the near blade boundary layer of wind turbines a rotating PIV system (R-PIV) is also under development at LANL (patent application in progress). Design considerations and results of bench top tests that confirm the reliability of PIV measurements obtained using the above diagnostics will be presented in this talk. PIV along with conductivity and temperature probe data has been useful to develop models that simulate the evolution of the layered structure of crude oil stored in the subterranean caverns of the Strategic Petroleum Reserves (SPR). Understanding the evolution of stratified layers of crude oil that are subjected to geothermal forcing is crucial in improving the efficiency of maintenance procedures carried out for the SPR and hence ensure Energy Security of the nation. Through analytical and experimental analysis it has been found that the dynamics of crude oil mixing are significantly affected by the presence of heating sidewalls of the storage caverns. Scaling laws that have been advanced for evolution of mixed layers for stratified fluid layers stored in slender containers will also be described in this presentation.