Spreadsheet calculations of jets in crossflow: opposed rows of inline and staggered round holes

Abstract

The objective of this study was to demonstrate and analyze empirical model results for jet-in-crossflow configurations which are typical in gas turbine combustors. Calculations in this paper, for opposed rows of round holes in both inline and staggered arrangements, were made with an Excel® spreadsheet implementation of a NASA-developed empirical model for the mean conserved scalar field. Results for cases of opposed rows of jets with the orifices on one side shifted by half the orifice spacing shows that staggering can improve the mixing, particularly for cases that would overpenetrate if the orifices were in an aligned configuration. For all cases investigated, the dimensionless variance of the mixture fraction decreased significantly with increasing downstream distance. The variation between cases at a given downstream location was smaller, but the “best” mixers for opposed rows of jets were found to be inline and staggered arrangements at an orifice spacing that is optimum for inline jets.