Authors: Sankaranarayanan Ravi Scott J Peltier Eric L Petersen
Publish Date: 2012/12/28
Volume: 54, Issue: 1, Pages: 1424-
Abstract
Turbulence statistics of three impellers with different geometric features were measured using particle image velocimetry inside a Plexiglas model ~11 scale of a cylindrical flame speed vessel 305 cm ID × 356 cm L With four impellers arranged in a centralsymmetric configuration turbulence intensities between 12 and 17 m/s with negligible mean flow 01u′ were attained at the lowest fan speeds Acceptable ranges for homogeneity and isotropy ratios of the velocity fields were set within a narrow bandwidth near unity 09–11 Homogeneity ratios were unaffected by changes to the impeller geometry and the prototype with the higher number of blades caused the flow to become anisotropic The integral length scale of the flow fields varied between 27 and 20 mm which correlates well with those typically observed inside a gas turbine combustor The mechanism to independently vary the intensity level and the integral length scale was established where turbulence intensity level was dependent on the rotational speed of the fan and the integral length scale decreased with increasing blade pitch angleThe authors would like to thank Dr Rodney Bowersox and Dr RAHumble Department of Aerospace Engineering Texas AM University for providing the PIV system The financial support from the US Department of Energy through the UTSR grant No DEFE0004679 is acknowledged SJ Peltier would like to acknowledge the support from the US Air Force Office of Scientific Research
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