Low Reynolds Number Dependence of Static Pressure Fluctuation Characteristics in Decaying Experimental Grid Turbulence Clarified by Highly Conservative Analysis

Abstract

The aim of this research is to investigate the decay properties of static pressure fluctuations in grid turbulence, with particular emphasis on the dependence of these properties on low Reynolds numbers in the streamwise direction. Specifically, this investigation addresses variations in the decay exponent of the root mean square (RMS) static pressure fluctuation within the low Reynolds number regime and contrasts this with the behavior of the turbulent kinetic energy. Using direct numerical analysis, the study employs precise methods to maintain the principles of energy and mass conservation. The results indicate that the grid turbulence analysis is accurately reproduced, with the decay exponent showing an increase at lower Reynolds numbers. In addition, a comparative analysis between the decay exponents of turbulent kinetic energy and static pressure fluctuation RMS has been carried out. This comparison shows a more pronounced increase in the decay exponent for static pressure fluctuation RMS. Correlation with a previous study using similar mesh Reynolds numbers and blockage ratios corroborates the observed decay exponent. These results provide important insights into the nature of grid turbulence and its decay phenomena.